At least a badly aligned press-fit BB interface isn't typically a lose-your-teeth problem. The ability of the bike industry to invent new uncertainties and failure modes is impressive.
Hookless isn't new. It was the norm for many decades but it wasn't tubeless. The tolerances of hookless tubeless are significantly better than those old hookless wheels/tires and better than early hooked clinchers too. I remember running 2 layers of thick cotton tape because a tire was too big. I also remember breaking beads because a tire was too small😂 I've also had sidewall blowouts on smooth roads with some of those absurdly tight tires, and I've had beads pop off the rim while riding because they were a bit too loose and I didn't add extra tape
The pen is not just working, it is stiffer and more responsive. Just like all bikes sold in 2024. More seriously, though, this is a really important video.
Yeah I agree. It has cemented my view I just won’t ride hookless. It’s just to save manufacturing costs and we are out at risk what’s the f ing point???
Rims do shrink when the tyre is inflated, reducing the BSD (bead seat diameter). How can you tell?Measure the spoke tension drop after mounting and inflating a tyre to 5 bar. Another reason to go for the safety of hooked (crotched). I have to say i think you explained the pressure vessel stuff really well and clearly.
Those with Giant SLR 0 (2020 Propel Advanced 0) will know this problem - perfectly straight wheel, mount tires not hookless compliant (Continental GP 5000 TL), wheel runs untrue. FWIW. The right tyre, on the right hookless wheel is extremely light, had no issues myself.
I ride almost exclusively road and gravel. Any hookless rim gets an immediate X drawn through it whenever I’m in the market for a new wheelset. For my MTB it could be an option where I know I’ll be running very low PSIs and encountering the hits MTB rides encounter. For a road or gravel wheel hookless is a non starter despite the marketing bullshat from the companies producing them and their paid online cheerleader clowns like David Arthur, etc.,..
Im an engineer myself, albeit electrical not mech, and just basic engineering common sense told me to stay away from hookless. I always wondered how its gonna stay put at all. The tire length argument filled the gap. Now I understand why it can work at all under stringent conditions. Thank you for providing reason to my gut feeling. I stay hooked with TPU.
As another engineer, I'd say hookless would be ok if it wasn't because of the terrible tolerances for bike tires and extremely flimsy rims. You'd need to make sure, like REALLY make sure the bead of the tire won't start fatiguing with use and that is made to a good tolerance.
I wanted to stay hooked with TPU but decided to spend money on a new Canyon bike .... therefore I'm forced into hookless because only very low end models still come with hooked now :( Still using TPU on hookless ZIPP 303 FC tho lol fuck tubeless
Not true. Like I said above if this was a REAL problem. Zipp would have been sued into oblivion in the US. Why hasn’t that happened?? If there was a real issue we’d already seen this here. I have Zipps and I see Zipps in every group I ride in. Where is the class action suit in the US against these manufacturers? There’s a freaking lawyer on every corner here waiting for you to burn your tongue on your coffee. Where are the lawsuits ? These rims have been around for 10 years
@@jimsteinway695 hookless zipps 10 years old? i dont think so. everything is good until its not, i hope the lawyers can bring you back to a full recovery or possibly back from the dead. gl with that. oh yea and the built in brake in the zipp hubs will make you stronger too. enjoy
You can not like the guy’s style, or like it (I do), but this explanation is priceless. Thx mate. Well done. Now clear as crystal that I’m sticking to tubes and hooks and all.
I've been waiting for this! Zipp's claim that he hit a rock and that caused the tire to come off is INSANE. When you're riding, you often ride over rocks! No thanks, Zipp.
Just looking at the inside of the cross section of the rim Hambini cut shows a cheaply fabricated rim. Yet they want $2,000 to $4000 for wheelsets with those cheaply fabricated rims and known cheap garbage hubs. Total joker product with joker MSRPs. 😀
I love how we go from lets fucking glue our tires to the rim a few years ago to hopefully the tire doesn't blow off because I blew 2 psi too much in it xD
As soon as the bike industry solves a problem, they go and create a new one. Remember the problems related to tubeless and rim combination at the introduction of the former on the market ?
The pros would ride solid rubber tires if the sponsor paid enough. "Vibration attenuation no longer matters". No more pneumatic tires allowed by UCI also. They'd get on board too!
Who needs the tyre to stop on their rim anyway? For ultimate thrill seekers everywhere match a Zipp hookless rim with a Shimano Hollowtech crank and see which tries to kill you first 😂 Both prime examples of cowboy engineering.
@ThePaulKat Yeah, and set it up with a non functioning SRAM front derailleur and a Zipp/SRAM non functioning rear wheel hub. And make sure it also comes with an undersized bearing SRAM DUB bottom bracket that you can regularly burn through. More cowboy engineering. 😀
Both the Lun and Zipp look horrendous inside ... more wrinkles than your grandpa's sac. Also, spongy walled Zipp rims are notorious, and they frequently delaminate.
Do you mean their new “hybrid hook” design? I was thinking of getting it for use with (TPU) tubes. I think it might provide enough hook to use with tubes above the tubeless pressure rating, while also being less prone to damage than a standard hook.
My engineering degree paid off in not jumping on the hookless train. Cycling industry is transforming but it pains me, at some point these designs will be more regulated. A bike is not a toy…
You don't need a degree in engineering to avoid crap pushed by marketing-mavens. Common-sense is enough but my time in bike retail proved it wasn't as common as one would like!
Thanks fine lad for cutting through all the marketing guff we drown in in this industry. We were presented with this style of rim last week to set up tubeless for an MTB. Using the tyre supplied, lets just say our very experienced mechanic "carefully" blew it off the rim 3 times at less than 40psi trying to seat it Two other tyre varieties were trialled before a satisfactory bead was established. Even still, neither of us would trust the bloody thing. Customer was informed to tread carefully{very]!
I've ridden road bikes about 25 years, 5 years hookless. I've had two blowoff on hooked rims (schwalbe tires Road Hutchinson mtb). No problems hookless. Both blown tire were very easy to mount. I have a feeling the hook does not change much the blowoff safety but easy to mount tire are dangerous. Vittoria are usually easy to mount.
I've been riding Vittoria exclusively since the 80's. Mostly Tubulars. More recently (2018) I started using there corsa control clinchers with Vittoria's pink latex tubes. Always 85 - 90 psi in a 25mm. I have never had a blowout or a flat. ( full disclosure: the roads where I live are mostly smooth and well maintained.)
It's not about whether the wheel is hooked or not, it's also in combination with a smaller tyre at lower pressure that makes hookless dangerous. The de Gendt incident was the team using 28mm Vittoria tyres with Zipp 25mm internal width hookless rims. The ISO states a minimum of 29mm tyres. When you unknowingly combine this with a lower tyre pressure (presumably unintentionally by the mechanic, maybe an inaccurate pump gauge?) or maybe slow leak, or maybe heat generated over time during the race, or a bump/pothole in the road... BOOM, tyre explodes.
Yes, the problem is the combination, a up to standard hookless + compatible tyre + correct pressure, it is as safe as you can get. But this is the hard part, manufacturers fuxkup + riders that does not have enough knowledge to know what tyre to put on, what preasure to use just have too much margin for errors. On the other hand, with hooked wheel, you can fuxkup a bit and you will still be fine.
I am riding giant hookless with their cadex tyres. As long as you stick to the allowable combination it’s a great system. Such a shame to see these self styled experts spreading fear to the sheep.
Zipp 530 wheelsets 20 years ago the alloy brake track debonded from the carbon v-section, zipp 188 rear hubs 10 years ago broke at the hub flanges where spokes mount, zipp firecrest rims went whiteish (faded) after time , zipp cognition clutch freewheel systems creak when dry, then there's this.
Zipp hookless have been around since 2013. If they’re so dangerous why isn’t there any lawsuits against Zipp? In the US if there was a real problem some bloodsucking lawyer would have had these eliminated 6 years ago
@jimsteinway695 An even better question. Why is a Zipp wheelset with such a cheaply and poorly Far East fabricated rim (as displayed in this vid) that also has known garbage quality hubs being solid for multiple thousands of dollars? Answer: lots of gullible and easily marketed to fools out there. 😀😀
A lot of people attribute the cost, ie is cheaper to make but they don't pass on the savings. From a technical perspective, they can make the system weight lighter. I don't think this problem would exist if the tyre and rim maker were the same. But, the wheel maker tyres are known to be shite eg cadex
@@Hambini the simplified manufacturing process and de-molding should lead to higher quality at lower cost with fewer voids and defects and less delamination. but that requires us to have confidence in the cycling industry's manufacturing consistency and QA, both of which appear to be lacking.
One other reason why manufacturers went hookless is because the carbon hooks had sharp edges which required additional surface treathment. The sharp edge cuts the tire beads causing blow outs.. pure cost saving for manufacturing. Customers have no advantage at all from hookless unless you favor the nurse in the hospital instead of the hairdresser..
Had my Zipp 303s with my Gravel bike for over 6months, no issues so far. Just changed tires over to Cinturato Gravel M 40mm. Others say a great tire for Zip 303s. Will let you know how the wheel and tires get on after my JOG ride.
correct me but if you hit something at high speed like going fast down hill the tyre will compress thus the pressure will increase and they say do not have a higher pressure than X. Hmmm. I don't think I will be buying hookless in the near future.
Yes, but the pros pump the tire to 1 psi before it blows of just standing still. Also their smaller tires, 28 mm and below, have much less air volume, so any compression from road interaction, raises the psi in the rest of the tire much higher, than say a 40 mm on a grave bike. It's all ridiculous, because pumping to for example 5 psi below treshold, instead of 1 psi below treshold, will decrease rolling resistance with close to noting, like below a watt. The pro peloton certainly aren't doing tubeless any favours, making it seem like a right hazard.
Yep, I bought a tcr a year ago, dumped the tubeless set up for tpu tubes and different tyres. Still crap myself using them, but have another set of hooked rims which I use mostly!!! I hate tubeless hookless crap, a solution for a small problem of moulding a hook!!!!!!!!
Dude these rims have been here for 10 years. If they’re so dangerous where are the class action lawsuits in the US? If there’s a safety issue they’d been sued already
@@jimsteinway695exactly this. These videos are just putting way too much fear out to the average cyclist. Hookless is solid , these self styled experts push their agenda , then at the end shill for Chinese brands such as Winspace.
@jimsteinway695 The vast majority of those bikes are MTBs running very low PSIs where hookless makes some sense. In the road you are dealing with much higher PSIs that can be death on a hookless rim wheel if you overinflate it even by not much. That’s why.
thanks, well explained! addition: friction is a function of the contact surface. if the tire does not fit well and is sitting too high on the hookless rim, the contact area is reduced. lower friction. hospital.
I went back to tubular on all my bikes last season and the ride quality is so much better. I went to the Alps on my Dura Ace 9100 C40’s and felt so safe and the cornering and braking were superb.
Thank you for doing this video. Hookless rims remind my of press fit BBs 15 years ago: Feasible on paper. A disaster when different manufacturers get involved. While noisy BBs are simply annoying, hookless rims hurt people.
Theres's another part to the drama that wasn't covered in this video but according to the etrto for the spec of those zipp wheels the minimum tire size should be 29mm whilst on zipp's website it says 28mm, which is what deGent was running I think..
For years, this happening has been one of the reasons why professional cyclists were initially wary of the implementation of tubeless compared to the *_traditional tubular whose main advantage was that, in case of a puncture, it allowed to keep rolling and stop safely_* as it remained attached to the rim.
I ride Sun CR18 rims with Panaracer tubes and tires. I get around 4 flats per year....at 10 min per flat that is almost an hour. They are also cheap, light, bulletproof
I’ve never considered the weakness of the hookless sidewall, I would imagine the lighter weight wheels like the NSW would not be as stiff and would allow outward flex under pressure causing a blow off 🤔 wow Hambini is the first I’ve seen to point this out. FYI the front wheel was a 353NSW with 25mm internal.
@@JayLato I find that hard to believe. What tire and what pressure? I’ve sold about 300 pairs of the 353, not a single issue. Not to mention the 454 and the firecrest line. I had one earlier today, sure enough guy installed tube type tires by mistake.
This is pure speculation by Hambini. He says he doesn't want to bull**** everyone with theory and then goes and does exactly that. Theory is useless in engineering unless you put numbers into the equations, which he can't do. Perhaps I'm biased because I do have Zipp hookless NSW and I did listen on. But for what it's worth, here's my experience running them tubeless with Continental GP5000 STR 28mm tyres. Firstly, fitting the tyres, they're relatively easy to get on although my thumbs weren't strong enough to do that without a lever. Seating them was amazing. They pumped up with a track pump just with normal pumping. I didn't even have to use a boost flow even though my pump has that feature. The surprising thing was that they then held their air even without sealant. My experience with pressures is very different to Hambini's. I weigh 11 stone and Zipp recommends 53-56 psi but far from the the Silca guidance (which is higher than Zipp's) being too low, I find it easy to run much lower pressures. This has not always been on purpose (e.g. after forgetting top up my sealant after a year on UK roads without any ride-stopping punctures). Even as low as 10 psi the tyres show no sign of coming off and why should they as they are firmly wedged between rims there's no pressure behind them to push them off? This is different to hooked rims. That is, whereas riding pushes hookless tyres in, hooked need pressure to keep the bead in the hook so when ridden with zero pressure they pop out. Personally, the only way I can see hookless tyres blowing off is by running them near the 70 psi limit under the mistaken belief that higher pressure is faster and then going over something kerb-like with such force that it breaks not just the tyre but the rim too. In that scenario, I'd probably be on my way to hospital whatever wheels I had. There does seem to be an optimum pressure where rolling resistance noticeably increases at very low pressures but again my experience is opposite to Hambini's: I find that optimum to be lower than the Zipp recommendation, not higher.
I run tubeless on my Roadbike/Gravel and Mtb. Since many Years, All of them Hookless. I ride 10k a year. I never had to stop with a flat since i switched to tubeless . The Milk always stop deflating the air. I use Conti gp5000 str 28 front and 30 rear on my 404 with 3.9bar . Gravelbike with 47mm Wtb, and Mtb with Specialized Fasttrack/Renegade. Its way more comfortable, and alot more grip in wet because of low pressure. No way i would switch back to tubes. My weight is just 67kg.
If there was a problem lawyers would have stopped this 8 years ago. These rims have been around since 2013. This just picked up steam because one guy had a blowout . I run Zipp 303s same thing no issues. Look for more copycat videos. The sky is falling!
Sorry, I have no desire to address a road problem that never existed by running tubeless and being forced to constantly refill my tires every few months with new sealant to address a road problem that never existed with hooked and tubes anyway. I’m funny that way. 😀😀
4:00 holy fuck those zipps have wrinkling ... 2k or something on those wheels? really glad l sold my 303 firecrests. they had fucked rear hub bearing ... a known issue with zipp and for 1.5k on wheels that is unacceptable. riding elite wheels currently
Silly prices for cheap fabricated junk wheelsets. That is a Zipp wheel in a nutshell. Not only is the fab of their rims mediocre at best, but their hubs are absolute Walmart level trash. Amazing that anyone would pay anything close to the silly nosebleed prices they ask for that junk. But the gullible and the posers will always be, well, gullible and posers. 😀
Given that hookless tyres are impossible to get off without first getting the beads into the centre of the track, then using tyre leaves and even then using considerable force, how exactly are underinflated hookless supposed to roll off?
Good vid. You mention that the sealant acts as a lubricant. However, when I remove a tyre from my hookless rim, the sealant has actually glued the tyre to the rim, requiring some effort to release it. The adhesion may not be uniform, though.
I’ve got a pair of Zipp 303s on my endurance bike with 32mm conti tires. I am not a racer and make sure to keep the psi at the appropriate level. Had no problems in 3 yrs, but do you think I need to find another wheel? How dangerous are these things in your judgment/how urgently do I need to replace if they are? Thanks for the video & the explanation. Cheers
Same here, I've got the 303S with big gravel tires. Every spontaneous hookless failure I've seen talked about on the internet involved someone running narrow road race tires. So I understand the paranoia but in the absence of compelling information to the contrary, I'm inclined to write this off as a road race problem. Maybe it's just post purchase rationalization though.
Same here if there was a problem lawyers in the US would have got these rims eliminated 9 years ago. One guy has a blowout and everyone is making a video. I AM an engineer I’ve had no problem with these rims or tires. This is all hogwash. The sky is falling!! The sky is falling!!
They aren't dangerous. The pros ride on Zipps, and elite CRIT riders use Zipps. This guy doesn't account for all variables and he doesn't do the calculations properly. It's a clickbait video in disguise.
Probably cycling industry should come up with specialist mounting paste for hookless rims so tires hold stronger on sidewalls? Meager $50 for 50ml bottle could drastically reduce risk of tire popping off rim, it's a win-win!
I don't have an engineering degree, but common sense tells me that introducing risks while getting little-to-no benefits seems unreasonable. Don't get me wrong, I think challenging a status quo is a good thing, but also I believe every cyclist has a vast interest in keeping tire on the wheel at all times.
@jimsteinway695 Bullshat. The vast majority of hookless are run on MTBs at very low PSIs. Road bikes running much higher PSIs is a completely different ballgame.
@@jimsteinway695 Nobody with any common sense runs 73 psi in MTB tyres! If you are happy with your set-up, great. There's no class action litigation, I imagine, because the average cyclist knows what works and what doesn't. Ignore industry marketing bs and avoiding putting one's self in harms way. For anyone else considering this for road use I see it as a form of natural selection.
Can't believe this became a thing for road cycling. Nox composites stated years ago the importance of tire pressure and use of hooked/hookless rims. Been riding those as prescribed for years w/ no problems. Also on brand new hooked Alpinist rims and Terra rims. All hooked. All perfectly fine.
Can you do a video on the following combination of tire, tube and wheel experiment? - Good quality hookless carbon fibre road time with; - Wire bead tubeless road tire (not necessarily folding, but the one that is specifically recommended for tubeless) measuring 25-35 mm and; -TPU tube, inflated to typical road pressure (65-90 psi). No sealant, ordinary rim tape. Try to bump this tire off the rim. What happens when a puncture occurs? Does the TPU tube prevent rapid loss of pressure? Does installing the tubeless tire with soap on the bead help with adhesion of the tire when the soap or tire wax has dried? Can you inflate to 140 PSI to see if the tire gets blown off the rim? What happens when a UST (Mavic Universal system tire) is used with TPU tube and recommended tire-rim combination?
This was an incredibly simple to understand video about this whole topic. So good, I can see it being used in court and a jury having to watch the pen check intro. Excellent writing today, new pen was SOLID.
@Team.TThhghchfgggcgv It makes some sense for MTbs running much lower PSI’s. Makes zero sense on a road or even most gravel bikes and addresses an essentially nonexistent issue in those disciplines.
I tried to run HEDs max pressure on my Jets (80psi iirc) and i never had so many pinch flats (tubes) in my life and even dinged a rim b/c of it. Back up to 95-100 f/r and it was same old same old mile after mile. -U10
Occurs to me that there's another variable that may be very difficult to account for. Sealant. Does it infiltrate the rim / bead interface? How much does it affect the coefficient of friction? Depends on the installation procedure, the pressure, the make up of the sealant, and perhaps the length of time since the install I guess? Perhaps it's not a massive thing, but surely significant?
There are so many variables with this point alone... I'd guess it could even make hookless slightly safer if it is a bit older and dried out at the rim, while it makes it unsafer if you spilled a lot on the rim while putting the tyre on.
I'd like to know, if tire bead strength decrease over time? Because I found the bead strength is ultimately THE thing that holds the trie from blowing off. I noticed that the bead becomes less and less tight after a few times of mounting my gp5000 to my zipp404. Does my mounting operation, i.e., using the tire lever to force the bead onto the rim, damage the bead strength?
I can remember when I first started mounting TUBULARS on rims, they tell me to stretch them a little, one end of the tub on the floor, put your foot on it and then pull upwards to slacken the fit a wee bit. This was because some brands were very tight to get on the rim. It still is the same today.... But hey ho better tight than too slack.(Use your imagination on that one I prefer Slack honestly 😂😂😂😂). But this never meant the tub would just POP off the rim unless some useless CNUT did'nt glue it on correctly...
@@RICHARD.WRIGHT1 If you know how to glue them, no popping off, no matching tables, no pressure worries, few or no snake bites, seldom or no rolling off when they puncture at speed, speedy to replace by the road, lightest possible rim...NO, we can´t have these, can we?? Rgr
I think the geometrical element is understated here. If the tire moves out on one side of the wheel, on the opposite side it's moving in, assuming it's a circle. That's not constrained by friction but by geometry. But for this to work the tolerances need to be tight. I don't know what led to the failure in this instance, but the rate of these failures is low. For example, if there's 300 pro racers (2 races per day, 150 riders per race), 3.3 hours per day every day for a month, and there's one failure, that's a failure per 30 thousand hours, . The tolerance for failure is even lower, but such a low failure rate implies a combination of factors, for example including out-of-spec equipment, is likely involved. I did really like the discussion of stress balancing. At first glance the "hoop stress" and the axial stress are orthogonal so cannot balance, so it takes some thought to resolve that.
I've got an older set of the rimbrake lun wheels. They are by far the best wheels for tubeless. No spoke holes, tires hold air for weeks, even without sealant.
Thousands of kilometers is done every single day on hookless wheels. Can someone please provide some links to all the accidents happening out there because of the wheels?
I'm not a scientist. But I am a lifelong bicyclist. I've seen fads and bad ideas come and go. As we evolve in technology, dumber ideas seem to be forced on the unknowing consumer. I hope we are at the pinnacle of dumb ideas. Because these salesman who no longer offer options, are going to be the death of the bicycle industry.
19:30 Just wanted to add that even though your cut Winspace wheels which are the hooked example in this video, doesnt mean all hooked rims got a hump (or two, cause each side), so technically this way of failure can still happen with hooked rims. Love the content, just adding info so people don't forget about differentiating and looking into stuff themselves!
My zipps 303s work well for me. Just done a 2000km ultra race. Nothing wrong with the wheelset. Been using sealant and tube on this wheelset. Going down steep mountain, hit pothole and still rolling well.
Congrats. You paid $2K plus for a cheaply and poorly Far East fabbed rim (as proven in this vid) with known garbage hubs to boot. Pat yourself on the back. Well done. LOL 😀😀
At 15:40 in the video, where you show a "gap" (the bead lifted away, or riding high on the rim), you talk about pressure under the bead. I would argue that the pressure pushing upward on the bottom of the bead, is that same no matter how small the gap. If you have 100psi in the tire, the bottom of that bead will have 100psi, even if the gap is almost zero. Thoughts?
What you said about high pressures is correct. On a smooth surface track pressures are at or near 200psi. But on the road the surface is not flat and incredibly irregular. Hence lower pressures are better on the road. Plus lower pressure help with comfort.
Dramatic improvements in comfort can also be gained by a decent set of knicks and cork bar tape. Without needing a bouncy rear end and pinch flats or damaged rims.
I’ve had DT Swiss GRC1400’s with Vitoria tyres fitted for the last year. Not running at stupid pressures as they’re gravel tyres. However they aren’t actually meant to be fitted to hookless wheels apparently, only realised recently!! Haven’t had a single issue with them though. The tyre is tight AF on the wheel during installation so I’m not worried it’s gonna blow off on a descent. Never say never though. For me this particular incident appears to be due to too high a pressure in the tyre and/or a heavier rider. Out of interest I wonder if those Vitoria tyres fitted were meant to be installed on hookless rims as a lot of them aren’t. There are manufacturers recommendations etc. interesting topic though. I am not an engineer but I certainly see the common sense side of this debate. Just saying that personally I’ve had no issues with the DT Swiss wheels or any of the other tyres I’ve had installed on them. Only run at 30 psi though so fairly low pressure. Which probably prevents any blow outs etc. For me it’s a happy medium of not too high a pressure equally not too low. The lip/sidewall on the DT Swiss rim is also quite thick (it’s a carbon one too) and appears to be of good quality and strong. I’ve bashed it hard on big rocks during descents and so far so good. Only had one incidence of a puncture due to a large impact on a rock and that was remedied by fitting a new tyre. Re tyres; you say Vitoria are sh*te but honestly in my experience they’ve been good so far even though they aren’t strictly meant to be installed on a hookless rim. I run the Terino dry mixed. Good grip. Have lasted long. Don’t seep through the sidewalls (unlike the continentals I’ve had, can’t remember where they’re made but it’s not China. Continental terra trails are now made in China not Germany. Re Pirelli, I’ve run those with no issue. You also said they are sh*t. This is a company with a rich history in rallying so not sure I agree there. Re Michelin I do agree with your conclusion great tyre manufacturer who provide good tyres for cars bikes whatever. Interesting topic. Hope this 2p is interesting!
I’ve got a set of these and had the unfortunate experience of the front tyre blowing off the rim at the top of a big climb apparently the shop sold me the wrong tyres ffs . Now I have no confidence in my zipp 303s wheel shame on them .
Would be nice if you could explain what the idea behind hookless rims is in the first place. Did not trust them when I saw the first pictures because I was asking where the clincher is supposed to hold to. But what would it require so hookless rims work as intended other than glue-on tubular tyre?
Such nonsense… dudes all freaking out here are clueless. Should hookless rims be a problem, you would see frequent accidents and a class action lawsuit going on for some time right now. To think that Zipp’s engineers wouldn’t do their homework properly and put a failed product in the market, risking the business reputation… please, give me a break. Just follow the guidelines. If you’re too heavy and afraid of over pressure, just get a regular hooked rim and conventional tube tires. That’s it. What a clickbait.
I love Hambini but he's spewing some BS. I've had hookless rims on all three of my bikes, Mountain, gravel, and road. I follow the guidelines and have never had a problem. I have hookless rims on my motorcycle and car. No problem. According to Hambini I should be absolutely terrified at all times. It's clickbait bullshit. Hambini is better than this.
What I think he’s saying is that there’s a greater risk with hookless not that it WILL fail. I know a guy who smoked a pack a day and he’s alive and kicking in his 80s….
@@MokaBoucha Sure, but the big question is: by how much? If there's just a marginal difference in risk between hooked and hookless eg, than all those discussions are pointless, but we simply dont know (also Hambini doesnt apparently).
If I’m running carbon on road I’m using Campagnolo hooked with continental tires. On MTB I use carbon hookless Chinese rims. I too tried the road lower pressure settings which feel great on flat roads with no pot holes or major road seams but in hilly mountain roads with road imperfections I had a few close calls. So back to more appropriate tire pressures
Hooked shills are the same as rim brake shills. the technology is better but refuse to accept. follow the manufacturers psi and approved tyre list and you wont have a problem.
Glad you covered the width. Have to admit I know its anecdotal, but running 28s on a Giant SLR1 which runs the 19.4 internal width on hookless. Havent had an issue such as this on mine, whereas the Zipps are 23 mm
With this excellent explanation, I don’t understand why a company would even consider the hookless variation. I mean, if they’re worth anything at all they must’ve at least made the same considerations?
@@marcvb3364 Cheaper, but also the rim is stronger, easier to make precisely, and needs less finishing. Not worth the risk of blowoff, but not purely them being cheap.
Always learn a lot watching these. The bit I'm curious about, isn't there a force in the opposite direction pulling the bead towards the rim because of the air pressure on the other side of the wheel? I don't really get how hookless work if I'm being honest.
Would the flex of the hookless rim as shown in the video at 23:30 be greater than as per design spec given the fact that you have cut the circular rim and thus reduced the tensile forces that only exist when the rim is a whole circle? It seems like your cut away sample is more like the plate form that you mentioned at 17:17 which seems quite different from the full circular rim as designed. Are the hookless rim parts as flexible when the wheel is whole as designed for use?
If this hookless thing was such a problem we would hear more about it long time ago. I think the biggest problem is that people are still putting 8bars in like in old times. My friend is riding 32mm tyre on 7bar and she has 50kg just because bike shop told her so when she bought the bike. When some bike shops are this slow to adopt new tech how can normal rider who just wants to ride know this things? Me and my wife both have zipp 303s and gp5000s tr and they works just fine but we are not some corner divers so we are never near the limit.
hookless literally blow off just sat looking at them with less than 70 PSI, lots of documented videos showing this! What benefit does it offer? Nothing whatsover!
Oh gee, because nobody has ever had a hooked rim and tire fail to seat and then blow the tire off when pumping it up. But I saw the hookless blow out on the internet!
Agreed. I think there are mistakes been made as regular cyclist and even mechanics at bike shops don't quite know about new tech. A friend had his tire blowing off the rim, he was using a tire not made for hookless rims, and 95 PSI. All of this because his mechanic had no idea this rim required an specific tire. In the Thomas de Gendt case, there was a bloody foam inside.
@davec5615 Oh gee, let’s put a hookless rim on a road bike or a gravel bike to address a nonexistent problem. Whoopeee look at me, my rim is hookless I bought into the marketing BS like a good little sheeple. LOL you clown. 😀
@Hambini Have you seen LightBicycle’s new “hybrid” hook? They advertise that it has a 5psi higher pressure limit for tubeless, but my interest is because it looks like it would be great with tubes - enough hook to act like a hook, but still thick and blunt enough to be tougher in the face of rim strikes. Dunno…
Hambini, I had gp4000 28mm on the back wheel for about 3-4000km. no issues. I installed a (brown wall) GP5000 28mm yesterday and it punctured in 9km!! Are they shite or was I v unlucky?
well punctures can happen with any tire, however the tan-wall gp5000 seem to be more fragile, teared the sidewalls rather quickly. black walled ones were more solid
I was expecting the equations to be populated with typical numbers and the elongation and likelyhood of a tire blowing off a rim to be analyzed. How much pressure does it take to blow particular tire off of a particular rim? And then run a test of the two!
Can't remember where I heard/read it, but apparently the ETRTO gave some guidance on minimum tyre size for a given internal rim width for hookless. It was larger than some manufacturers were saying was safe. Probably explains that chart you had up at 22:06
@@adamkenny5673There should definitely be a recall. I worked for one of the pioneer carbon bike brands. We had a recall because some steerer tubes had been made with inconsistent wall thickness, and could therefore fail. The recall was a major factor in the brand's bankruptcy. Brands cannot insure against recall costs, Recalls are very, very expensive to conduct, and a brand's various international distributors may not all be fully supportive and compliant - becasue they are expected to take action for which they will recieve no financial reward. Likewise the retail dealers supplied by those distributors. I was handed the unenviable task of heading up the aforementioned global recall operation. I did my very best, but it was a huge mess and the brand never recovered. Brands which have released hookless rims could very possibly be critically damaged by this.
I remember my biking history -- first department store "road" bike I was riding rocked chrome plated steel clincher rims -- lots of fun braking in the rain. Hookless of course as they had been made that way for decades. I don't remember narrow aluminum hooked rims coming in until the late 70s early 80s, and for safety reasons they were a requirement for the then new foldable clincher tires, which unless you were riding tubulars, they were what you used as a serious cyclist. I can see the modern corporate desire to make things a little easier and cheaper on themselves by eliminating undercuts in the molds like the safety hooks -- just another projected business expense when something goes wrong...
What about (xc-)MTB use? The hook-less edge can be made much thicker. And there for better at dealing with impacts with the ground as a result of the extremely low tire pressures (1 bar is not uncommon). (that is also why mtb use (light weight) inserts; better protection for the rim and side wall support) I agree with you that for road use the pressures (that you should be running) are to high for hook-less and not a option. But for MTB (offroad) lower pressures do result in less roiling resistance and more grip.
Hookless clincher rims were the standard in the ‘70’s, but as high-performance clincher tires arrived in the ‘80’s, hooked rims (and their ability to hold those tires at their recommended psi) became the norm. So, it made me scratch my head a few years ago when high-tech carbon rims started appearing with “hookless” being a selling point. A weird marriage of high-tech materials with a step back to an outdated design! Kind of like a modern sports car being marketed as having a “technologically advanced” carburetor!
The sealant ... as a lube 😶 I thought it set up somewhat sealing and holding the beed in place a bit. 2 sets of Zipp 303 S.. tuning 30mm though (one measures at 32mm).
I unknowingly had hookless clicher rims years ago and seem to be ok. Later were not used but after few years I happened to use them and blew tires off (yes high pressure). Had to figure out they were different then all my other rims, I had no idea.
What's next? Toothless cassettes and chainrings?
Odd number narrow wide chainrings😳😅
Wireless brakes.
@@911normanI wouldn’t put it past these maroons, you only think you’re joking
SRAM will introduce a NEW chain roller standard!! Joy to all!!! Rgr
Toothless riders?
At least a badly aligned press-fit BB interface isn't typically a lose-your-teeth problem. The ability of the bike industry to invent new uncertainties and failure modes is impressive.
Bike industry: what is failure mode 😂😂😂
Hookless isn't new. It was the norm for many decades but it wasn't tubeless. The tolerances of hookless tubeless are significantly better than those old hookless wheels/tires and better than early hooked clinchers too. I remember running 2 layers of thick cotton tape because a tire was too big. I also remember breaking beads because a tire was too small😂 I've also had sidewall blowouts on smooth roads with some of those absurdly tight tires, and I've had beads pop off the rim while riding because they were a bit too loose and I didn't add extra tape
What is more impressive is ppl still buying this overpriced marketed bullsh1t and believe it is a space-engineering R&D work they are paying for:)
@veganpotterthevegan that's a lot
@@veganpottertheveganI think you had those problems because you’re vegan. Meat eaters don’t have such problems
The pen is not just working, it is stiffer and more responsive. Just like all bikes sold in 2024. More seriously, though, this is a really important video.
Yeah I agree. It has cemented my view I just won’t ride hookless. It’s just to save manufacturing costs and we are out at risk what’s the f ing point???
the problem are youtubers and paid ''testes'' and recommendations
ppl are just sheeps, stupid sheeps with too much money end massive ego
Rims do shrink when the tyre is inflated, reducing the BSD (bead seat diameter). How can you tell?Measure the spoke tension drop after mounting and inflating a tyre to 5 bar. Another reason to go for the safety of hooked (crotched). I have to say i think you explained the pressure vessel stuff really well and clearly.
That's very likely part of the reason tubulars roll off rims too.
This video plus yours was an extremely thorough engineering perspective on the whole issue.
The tag team partners in full effect
Are you telling me a carbon fiber rim shrinks when there is a tire inflated to 4 bar installed on it?
Those with Giant SLR 0 (2020 Propel Advanced 0) will know this problem - perfectly straight wheel, mount tires not hookless compliant (Continental GP 5000 TL), wheel runs untrue.
FWIW. The right tyre, on the right hookless wheel is extremely light, had no issues myself.
"Only give credits to people with decent size pens...."
Well, there goes that.
Go hookless if you favor a nurse instead of your hairdresser😂
Don’t go for nurses brother, always ends bad
I also choose hookers.
I ride almost exclusively road and gravel. Any hookless rim gets an immediate X drawn through it whenever I’m in the market for a new wheelset. For my MTB it could be an option where I know I’ll be running very low PSIs and encountering the hits MTB rides encounter. For a road or gravel wheel hookless is a non starter despite the marketing bullshat from the companies producing them and their paid online cheerleader clowns like David Arthur, etc.,..
What go hookers...? ahh you wrote hookless. Never mind😊
@@rcg9573 Hookless is 100% safe. Period.
Im an engineer myself, albeit electrical not mech, and just basic engineering common sense told me to stay away from hookless. I always wondered how its gonna stay put at all. The tire length argument filled the gap. Now I understand why it can work at all under stringent conditions. Thank you for providing reason to my gut feeling. I stay hooked with TPU.
As another engineer, I'd say hookless would be ok if it wasn't because of the terrible tolerances for bike tires and extremely flimsy rims. You'd need to make sure, like REALLY make sure the bead of the tire won't start fatiguing with use and that is made to a good tolerance.
I wanted to stay hooked with TPU but decided to spend money on a new Canyon bike .... therefore I'm forced into hookless because only very low end models still come with hooked now :( Still using TPU on hookless ZIPP 303 FC tho lol fuck tubeless
@@thebrunoserge I think the swiss side wheels still have hooks. Just stay away from the zipps
@@onepunchbud1472 too late been using zipps. Returning the whole canyon bike was a pain I gave up
hookless tires are literally held together by hopes and dreams 😭😭
thoughts and prayers
Hoops and screams.
Not true. Like I said above if this was a REAL problem. Zipp would have been sued into oblivion in the US. Why hasn’t that happened?? If there was a real issue we’d already seen this here. I have Zipps and I see Zipps in every group I ride in. Where is the class action suit in the US against these manufacturers? There’s a freaking lawyer on every corner here waiting for you to burn your tongue on your coffee. Where are the lawsuits ? These rims have been around for 10 years
@@jimsteinway695 hookless zipps 10 years old? i dont think so. everything is good until its not, i hope the lawyers can bring you back to a full recovery or possibly back from the dead. gl with that. oh yea and the built in brake in the zipp hubs will make you stronger too. enjoy
@@jimsteinway695 You sound like someone desperately trying to justify your purchase. 🤣
You can not like the guy’s style, or like it (I do), but this explanation is priceless. Thx mate. Well done.
Now clear as crystal that I’m sticking to tubes and hooks and all.
But the issue is, its not. Yes, it sounds very plausible, but he didnt test/proof anything.
I've been waiting for this! Zipp's claim that he hit a rock and that caused the tire to come off is INSANE. When you're riding, you often ride over rocks! No thanks, Zipp.
Just looking at the inside of the cross section of the rim Hambini cut shows a cheaply fabricated rim. Yet they want $2,000 to $4000 for wheelsets with those cheaply fabricated rims and known cheap garbage hubs. Total joker product with joker MSRPs. 😀
@@rcg9573 youre summing up the current bike industry
@the.communist
Yes, unfortunately you are correct there!
I love how we go from lets fucking glue our tires to the rim a few years ago to hopefully the tire doesn't blow off because I blew 2 psi too much in it xD
or blow off because i put the pressure close enough to the limit that the heat from the road put them over :P
... 2 psi too many*
This is the best explanation of the failure modes of hookless that I've seen. The discussion re. low pressures around 18:30 was eye opening.
What failures?
As soon as the bike industry solves a problem, they go and create a new one.
Remember the problems related to tubeless and rim combination at the introduction of the former on the market ?
hookless is just way cheaper to manufacture and QC so the margins are higher. They solve a profitability problem, no more
Hooked bead rims were a solution to poor manufacturing. They are no longer required.
@@Omar411269Than why did they also decrease rim prices?
@@portland675 maybe because customers know theyre unsafe and arent buying them
@@Omar411269 nah, I’ve sold thousands.
I ride Zipp 303 and 404 hookless for road and gravel. They perform wonderfully and never had any issues.
Same with me. Don’t worry about this guy.
Faith will keep your skin in place. Keep believing.
There are none so blind as those who will not see!
everybody posting here will say the same - the others do not post anything anymore... it reminds me of the helmet discussion ~30 years ago
Most people that drove ford pintos and never died. Didn't mean they were safe. They were lucky.
Good luck! ;) (I'm a trauma nurse).
The ONLY hookless technology EVER, was gradually pushed aside by the pros: TUBULARS.
Not by the riders, but the teams
The pros would ride solid rubber tires if the sponsor paid enough. "Vibration attenuation no longer matters". No more pneumatic tires allowed by UCI also. They'd get on board too!
Who needs the tyre to stop on their rim anyway? For ultimate thrill seekers everywhere match a Zipp hookless rim with a Shimano Hollowtech crank and see which tries to kill you first 😂
Both prime examples of cowboy engineering.
Modern clinchers got so good they basically made tube redundant. A modern clincher on a TPU tube is cheaper, less hassle and in most cases faster.
@ThePaulKat
Yeah, and set it up with a non functioning SRAM front derailleur and a Zipp/SRAM non functioning rear wheel hub. And make sure it also comes with an undersized bearing SRAM DUB bottom bracket that you can regularly burn through. More cowboy engineering. 😀
Good explanation…. as a civil engineer I appreciate the clarity, the math and the safety aspect. Weight weenies take note
There is more to life than trying to reduce the weight of our bikes.
@@davidkennedy4845especially when we had super light bikes already before the disc brake era. And they were safe...
Both the Lun and Zipp look horrendous inside ... more wrinkles than your grandpa's sac. Also, spongy walled Zipp rims are notorious, and they frequently delaminate.
Yep! Terrible 3:51 for the zipp and winspace
@@Hambiniif you say, even winspace. Which wheel is then worth to buy then?😢
😂
@@desdundodafabosch1047 9Velo
@@desdundodafabosch1047 FFWD looks better than those on the inside.
My favourite rims are Lightbicycle. There hook design works actually really well even with super tight tubeless tires (Conti GP5000)
Do you mean their new “hybrid hook” design? I was thinking of getting it for use with (TPU) tubes. I think it might provide enough hook to use with tubes above the tubeless pressure rating, while also being less prone to damage than a standard hook.
... Their* (!) hook design
My engineering degree paid off in not jumping on the hookless train. Cycling industry is transforming but it pains me, at some point these designs will be more regulated. A bike is not a toy…
You don't need a degree in engineering to avoid crap pushed by marketing-mavens. Common-sense is enough but my time in bike retail proved it wasn't as common as one would like!
Always was, always will be...
@@larryt.atcycleitalia5786
However dentist & some dumb rich always buy crap pushed by marketing mavens lol
Thanks fine lad for cutting through all the marketing guff we drown in in this industry. We were presented with this style of rim last week to set up tubeless for an MTB. Using the tyre supplied, lets just say our very experienced mechanic "carefully" blew it off the rim 3 times at less than 40psi trying to seat it Two other tyre varieties were trialled before a satisfactory bead was established. Even still, neither of us would trust the bloody thing. Customer was informed to tread carefully{very]!
I've ridden road bikes about 25 years, 5 years hookless. I've had two blowoff on hooked rims (schwalbe tires Road Hutchinson mtb). No problems hookless. Both blown tire were very easy to mount. I have a feeling the hook does not change much the blowoff safety but easy to mount tire are dangerous. Vittoria are usually easy to mount.
I've been riding Vittoria exclusively since the 80's. Mostly Tubulars. More recently (2018) I started using there corsa control clinchers with Vittoria's pink latex tubes. Always 85 - 90 psi in a 25mm. I have never had a blowout or a flat. ( full disclosure: the roads where I live are mostly smooth and well maintained.)
It's not about whether the wheel is hooked or not, it's also in combination with a smaller tyre at lower pressure that makes hookless dangerous.
The de Gendt incident was the team using 28mm Vittoria tyres with Zipp 25mm internal width hookless rims.
The ISO states a minimum of 29mm tyres.
When you unknowingly combine this with a lower tyre pressure (presumably unintentionally by the mechanic, maybe an inaccurate pump gauge?) or maybe slow leak, or maybe heat generated over time during the race, or a bump/pothole in the road... BOOM, tyre explodes.
Yes, the problem is the combination, a up to standard hookless + compatible tyre + correct pressure, it is as safe as you can get. But this is the hard part, manufacturers fuxkup + riders that does not have enough knowledge to know what tyre to put on, what preasure to use just have too much margin for errors. On the other hand, with hooked wheel, you can fuxkup a bit and you will still be fine.
I am riding giant hookless with their cadex tyres. As long as you stick to the allowable combination it’s a great system. Such a shame to see these self styled experts spreading fear to the sheep.
Add the fact that there was a foam inside.@@brotherfranciz
My hairdresser just bought some NTN bearing from your site, thank you Hambini.
Thanks for this clear explanation. I'm "arts and crafts" but managed to follow along without difficulty👍.
Zipp 530 wheelsets 20 years ago the alloy brake track debonded from the carbon v-section, zipp 188 rear hubs 10 years ago broke at the hub flanges where spokes mount, zipp firecrest rims went whiteish (faded) after time , zipp cognition clutch freewheel systems creak when dry, then there's this.
I thought their stuff was OK before SRAM bought the thing and put it under a serious "product cheapening department" regimen?
I had clubmates with zipp 530s back then and the the debonding was experienced first hand
Zipp hookless have been around since 2013. If they’re so dangerous why isn’t there any lawsuits against Zipp? In the US if there was a real problem some bloodsucking lawyer would have had these eliminated 6 years ago
@jimsteinway695
An even better question.
Why is a Zipp wheelset with such a cheaply and poorly Far East fabricated rim (as displayed in this vid) that also has known garbage quality hubs being solid for multiple thousands of dollars?
Answer: lots of gullible and easily marketed to fools out there. 😀😀
Continental Gatorskin user here. I multitask my bike; good for all surfaces. Here’s my question; what are the advantages of a hookless rim?
A lot of people attribute the cost, ie is cheaper to make but they don't pass on the savings. From a technical perspective, they can make the system weight lighter. I don't think this problem would exist if the tyre and rim maker were the same. But, the wheel maker tyres are known to be shite eg cadex
@@Hambini the simplified manufacturing process and de-molding should lead to higher quality at lower cost with fewer voids and defects and less delamination. but that requires us to have confidence in the cycling industry's manufacturing consistency and QA, both of which appear to be lacking.
@@Hambini all very good arguments to use rimbrakes 😀
@@MrMichaelfalk You don't get the inevitable rub either.
One other reason why manufacturers went hookless is because the carbon hooks had sharp edges which required additional surface treathment. The sharp edge cuts the tire beads causing blow outs.. pure cost saving for manufacturing. Customers have no advantage at all from hookless unless you favor the nurse in the hospital instead of the hairdresser..
Hopefully, market pressure and negative press will quickly correct this insanity!
Chinese makers of hooked rims will show the way to the dump. Rgr
If there was a real issues lawyers in the US would have stopped these 9 years ago. These rims have been around since 2013
Very good and thorough explanation. Thanks.
Had my Zipp 303s with my Gravel bike for over 6months, no issues so far. Just changed tires over to Cinturato Gravel M 40mm. Others say a great tire for Zip 303s. Will let you know how the wheel and tires get on after my JOG ride.
correct me but if you hit something at high speed like going fast down hill the tyre will compress thus the pressure will increase and they say do not have a higher pressure than X. Hmmm. I don't think I will be buying hookless in the near future.
Yes, but the pros pump the tire to 1 psi before it blows of just standing still. Also their smaller tires, 28 mm and below, have much less air volume, so any compression from road interaction, raises the psi in the rest of the tire much higher, than say a 40 mm on a grave bike.
It's all ridiculous, because pumping to for example 5 psi below treshold, instead of 1 psi below treshold, will decrease rolling resistance with close to noting, like below a watt. The pro peloton certainly aren't doing tubeless any favours, making it seem like a right hazard.
To think these come STANDARD on all GIANT road bikes fuxking hell
Yep, I bought a tcr a year ago, dumped the tubeless set up for tpu tubes and different tyres. Still crap myself using them, but have another set of hooked rims which I use mostly!!! I hate tubeless hookless crap, a solution for a small problem of moulding a hook!!!!!!!!
giant revolt doesn't have a hookless rim but that's gravel bike..i refilled the sealant so i know its a hooked rim.
Dude these rims have been here for 10 years. If they’re so dangerous where are the class action lawsuits in the US? If there’s a safety issue they’d been sued already
@@jimsteinway695exactly this. These videos are just putting way too much fear out to the average cyclist. Hookless is solid , these self styled experts push their agenda , then at the end shill for Chinese brands such as Winspace.
@jimsteinway695
The vast majority of those bikes are MTBs running very low PSIs where hookless makes some sense. In the road you are dealing with much higher PSIs that can be death on a hookless rim wheel if you overinflate it even by not much. That’s why.
My oh my, Legendary Reaming incoming
thanks, well explained!
addition: friction is a function of the contact surface. if the tire does not fit well and is sitting too high on the hookless rim, the contact area is reduced. lower friction. hospital.
No problem for me, because I’m still gluing on tubs!😂
Yeah tubbies are the best!
no they are not, get on with the time and go tubeless
@@TheHardCorePunkHead
New bike came with tubs (C40 DA9100). Braking is horrible but the ride is heavenly
For racing I will always ride tubulars. I currently have around 8 sets, looking at a set of Kappius components for the coming season.
I went back to tubular on all my bikes last season and the ride quality is so much better.
I went to the Alps on my Dura Ace 9100 C40’s and felt so safe and the cornering and braking were superb.
Thank you for doing this video. Hookless rims remind my of press fit BBs 15 years ago: Feasible on paper. A disaster when different manufacturers get involved. While noisy BBs are simply annoying, hookless rims hurt people.
They’ve been around for 11 years, why no lawsuits if they’re dangerous?? In the US lawyers would have stopped Zipp 9 years ago
Theres's another part to the drama that wasn't covered in this video but according to the etrto for the spec of those zipp wheels the minimum tire size should be 29mm whilst on zipp's website it says 28mm, which is what deGent was running I think..
not even a sarcastic question: does the aero shape even properly do its job if you put something bigger than 28/29mm on this rim?
For years, this happening has been one of the reasons why professional cyclists were initially wary of the implementation of tubeless compared to the *_traditional tubular whose main advantage was that, in case of a puncture, it allowed to keep rolling and stop safely_* as it remained attached to the rim.
There have been plenty of accidents with tubular tyres being rolled off. There's no evidence yet that this is more likely with hookless.
I ride Sun CR18 rims with Panaracer tubes and tires. I get around 4 flats per year....at 10 min per flat that is almost an hour.
They are also cheap, light, bulletproof
I run tubeless and get zero flats per year. That's despite doing thousands of miles in UK weather on rain soaked roads.
I’ve never considered the weakness of the hookless sidewall, I would imagine the lighter weight wheels like the NSW would not be as stiff and would allow outward flex under pressure causing a blow off 🤔 wow Hambini is the first I’ve seen to point this out.
FYI the front wheel was a 353NSW with 25mm internal.
The tire didn’t blow off the rim though.
@@portland675I have personal experience with 2 different in spec tires blowing off my 353NSW
@@JayLato I find that hard to believe. What tire and what pressure? I’ve sold about 300 pairs of the 353, not a single issue. Not to mention the 454 and the firecrest line. I had one earlier today, sure enough guy installed tube type tires by mistake.
This is pure speculation by Hambini. He says he doesn't want to bull**** everyone with theory and then goes and does exactly that. Theory is useless in engineering unless you put numbers into the equations, which he can't do.
Perhaps I'm biased because I do have Zipp hookless NSW and I did listen on. But for what it's worth, here's my experience running them tubeless with Continental GP5000 STR 28mm tyres.
Firstly, fitting the tyres, they're relatively easy to get on although my thumbs weren't strong enough to do that without a lever.
Seating them was amazing. They pumped up with a track pump just with normal pumping. I didn't even have to use a boost flow even though my pump has that feature. The surprising thing was that they then held their air even without sealant.
My experience with pressures is very different to Hambini's.
I weigh 11 stone and Zipp recommends 53-56 psi but far from the the Silca guidance (which is higher than Zipp's) being too low, I find it easy to run much lower pressures. This has not always been on purpose (e.g. after forgetting top up my sealant after a year on UK roads without any ride-stopping punctures). Even as low as 10 psi the tyres show no sign of coming off and why should they as they are firmly wedged between rims there's no pressure behind them to push them off? This is different to hooked rims. That is, whereas riding pushes hookless tyres in, hooked need pressure to keep the bead in the hook so when ridden with zero pressure they pop out. Personally, the only way I can see hookless tyres blowing off is by running them near the 70 psi limit under the mistaken belief that higher pressure is faster and then going over something kerb-like with such force that it breaks not just the tyre but the rim too. In that scenario, I'd probably be on my way to hospital whatever wheels I had.
There does seem to be an optimum pressure where rolling resistance noticeably increases at very low pressures but again my experience is opposite to Hambini's: I find that optimum to be lower than the Zipp recommendation, not higher.
11 stone? 😂
I run tubeless on my Roadbike/Gravel and Mtb. Since many Years, All of them Hookless. I ride 10k a year. I never had to stop with a flat since i switched to tubeless . The Milk always stop deflating the air. I use Conti gp5000 str 28 front and 30 rear on my 404 with 3.9bar . Gravelbike with 47mm Wtb, and Mtb with Specialized Fasttrack/Renegade. Its way more comfortable, and alot more grip in wet because of low pressure. No way i would switch back to tubes. My weight is just 67kg.
If there was a problem lawyers would have stopped this 8 years ago. These rims have been around since 2013. This just picked up steam because one guy had a blowout . I run Zipp 303s same thing no issues. Look for more copycat videos. The sky is falling!
Sorry, I have no desire to address a road problem that never existed by running tubeless and being forced to constantly refill my tires every few months with new sealant to address a road problem that never existed with hooked and tubes anyway. I’m funny that way. 😀😀
@@jimsteinway695 you cant say these hookless rims are safer in any case
4:00 holy fuck those zipps have wrinkling ... 2k or something on those wheels? really glad l sold my 303 firecrests. they had fucked rear hub bearing ... a known issue with zipp and for 1.5k on wheels that is unacceptable. riding elite wheels currently
Silly prices for cheap fabricated junk wheelsets. That is a Zipp wheel in a nutshell.
Not only is the fab of their rims mediocre at best, but their hubs are absolute Walmart level trash. Amazing that anyone would pay anything close to the silly nosebleed prices they ask for that junk. But the gullible and the posers will always be, well, gullible and posers. 😀
LOL....LOOK AWAY RIGHT NOW!! Thanks for the awesome explanation.
so with hookless, if you overinflate you get a blow off, if you underinflate you can get a roll off. Great system.
Given that hookless tyres are impossible to get off without first getting the beads into the centre of the track, then using tyre leaves and even then using considerable force, how exactly are underinflated hookless supposed to roll off?
Good vid. You mention that the sealant acts as a lubricant. However, when I remove a tyre from my hookless rim, the sealant has actually glued the tyre to the rim, requiring some effort to release it. The adhesion may not be uniform, though.
Yeah I also think that's bullshit.
Maybe when sealant has dried out, but while still liquid it would serve as a lubricant. And if rain
reliquified it, could slick it up at a bad time.
@@Up2L842moro Ever tried removing a tubeless tire with sealant? The sealant glues it to the side of the rim.
I’ve got a pair of Zipp 303s on my endurance bike with 32mm conti tires. I am not a racer and make sure to keep the psi at the appropriate level. Had no problems in 3 yrs, but do you think I need to find another wheel? How dangerous are these things in your judgment/how urgently do I need to replace if they are? Thanks for the video & the explanation. Cheers
wait for an official UCI announcement. but in the meantime I would stick to known safe tires, and only 30mm+ tires.
Same here, I've got the 303S with big gravel tires. Every spontaneous hookless failure I've seen talked about on the internet involved someone running narrow road race tires. So I understand the paranoia but in the absence of compelling information to the contrary, I'm inclined to write this off as a road race problem. Maybe it's just post purchase rationalization though.
Sticking to the Conti GP 5000 S TRs. Thanks for the help folks
Same here if there was a problem lawyers in the US would have got these rims eliminated 9 years ago. One guy has a blowout and everyone is making a video. I AM an engineer I’ve had no problem with these rims or tires.
This is all hogwash.
The sky is falling!! The sky is falling!!
They aren't dangerous. The pros ride on Zipps, and elite CRIT riders use Zipps. This guy doesn't account for all variables and he doesn't do the calculations properly. It's a clickbait video in disguise.
Probably cycling industry should come up with specialist mounting paste for hookless rims so tires hold stronger on sidewalls? Meager $50 for 50ml bottle could drastically reduce risk of tire popping off rim, it's a win-win!
I don't have an engineering degree, but common sense tells me that introducing risks while getting little-to-no benefits seems unreasonable. Don't get me wrong, I think challenging a status quo is a good thing, but also I believe every cyclist has a vast interest in keeping tire on the wheel at all times.
Oh, but there are enormous benefits… just not for the consumer.
Cyclist have been using these for 11 years. There’s no problem or these rims would have been sued out of existence
@jimsteinway695
Bullshat. The vast majority of hookless are run on MTBs at very low PSIs. Road bikes running much higher PSIs is a completely different ballgame.
@@rcg9573 bullshit. 73 psi compared to 120 in 23mm tires or 180 in tubulars that are hookless also. Try doing some research
@@jimsteinway695 Nobody with any common sense runs 73 psi in MTB tyres!
If you are happy with your set-up, great.
There's no class action litigation, I imagine, because the average cyclist knows what works and what doesn't. Ignore industry marketing bs and avoiding putting one's self in harms way.
For anyone else considering this for road use I see it as a form of natural selection.
Excellent summary. Worth watching!
Thank You for clear demonstration of geometry-related safety issue with hookles.
Now I know specifically why to avoid them and stick to hooked rims. 👍
Go Tubular, you'll never look back.
Can't believe this became a thing for road cycling. Nox composites stated years ago the importance of tire pressure and use of hooked/hookless rims. Been riding those as prescribed for years w/ no problems. Also on brand new hooked Alpinist rims and Terra rims. All hooked. All perfectly fine.
Great vid matey.... keep it up.
Can you do a video on the following combination of tire, tube and wheel experiment?
- Good quality hookless carbon fibre road time with;
- Wire bead tubeless road tire (not necessarily folding, but the one that is specifically recommended for tubeless) measuring 25-35 mm and;
-TPU tube, inflated to typical road pressure (65-90 psi). No sealant, ordinary rim tape.
Try to bump this tire off the rim. What happens when a puncture occurs? Does the TPU tube prevent rapid loss of pressure? Does installing the tubeless tire with soap on the bead help with adhesion of the tire when the soap or tire wax has dried? Can you inflate to 140 PSI to see if the tire gets blown off the rim? What happens when a UST (Mavic Universal system tire) is used with TPU tube and recommended tire-rim combination?
This was an incredibly simple to understand video about this whole topic. So good, I can see it being used in court and a jury having to watch the pen check intro.
Excellent writing today, new pen was SOLID.
I've been looking forward to this ripping.
I still dont understand how come something "hookless" can be used in high pressure enviroment. Might done well in MTB area, but in road cycling?!
It’s pretty much been used in mtb for years without any problem. But you’re maybe running 35psi max on a 2.4 inch tyre.
@@Ryan.T89 No, you are right it is ok for MTB, but for the road cycling it is not alright. (for my perspective)
@Team.TThhghchfgggcgv
It makes some sense for MTbs running much lower PSI’s. Makes zero sense on a road or even most gravel bikes and addresses an essentially nonexistent issue in those disciplines.
I tried to run HEDs max pressure on my Jets (80psi iirc) and i never had so many pinch flats (tubes) in my life and even dinged a rim b/c of it. Back up to 95-100 f/r and it was same old same old mile after mile. -U10
Had the exact same experience with my jets. Serveral front and rear pinch flats when riding in a group.
I think they should invent rimless wheels. The spokes could attach straight to the tyre. It would save some weight.
...spokeless, held in place by chemtrails...
@@OGillo2001genius. Patent it
Occurs to me that there's another variable that may be very difficult to account for. Sealant. Does it infiltrate the rim / bead interface? How much does it affect the coefficient of friction? Depends on the installation procedure, the pressure, the make up of the sealant, and perhaps the length of time since the install I guess? Perhaps it's not a massive thing, but surely significant?
There are so many variables with this point alone... I'd guess it could even make hookless slightly safer if it is a bit older and dried out at the rim, while it makes it unsafer if you spilled a lot on the rim while putting the tyre on.
I'd like to know, if tire bead strength decrease over time? Because I found the bead strength is ultimately THE thing that holds the trie from blowing off.
I noticed that the bead becomes less and less tight after a few times of mounting my gp5000 to my zipp404. Does my mounting operation, i.e., using the tire lever to force the bead onto the rim, damage the bead strength?
anecdotally, every tire I've had has gotten slightly wider over time. I haven't over-pressured them. That suggests creep is going on.
The only totally nonstretch bead is most probably steel. There goes the weight advantage. Rgr
I can remember when I first started mounting TUBULARS on rims, they tell me to stretch them a little, one end of the tub on the floor, put your foot on it and then pull upwards to slacken the fit a wee bit. This was because some brands were very tight to get on the rim. It still is the same today.... But hey ho better tight than too slack.(Use your imagination on that one I prefer Slack honestly 😂😂😂😂). But this never meant the tub would just POP off the rim unless some useless CNUT did'nt glue it on correctly...
@@RICHARD.WRIGHT1 If you know how to glue them, no popping off, no matching tables, no pressure worries, few or no snake bites, seldom or no rolling off when they puncture at speed, speedy to replace by the road, lightest possible rim...NO, we can´t have these, can we?? Rgr
@@borano2031 I always used to have VELOFLEX tubs or Panaracer(when I was at school). The best feeling any tire can provide.
I think the geometrical element is understated here. If the tire moves out on one side of the wheel, on the opposite side it's moving in, assuming it's a circle. That's not constrained by friction but by geometry. But for this to work the tolerances need to be tight.
I don't know what led to the failure in this instance, but the rate of these failures is low. For example, if there's 300 pro racers (2 races per day, 150 riders per race), 3.3 hours per day every day for a month, and there's one failure, that's a failure per 30 thousand hours, . The tolerance for failure is even lower, but such a low failure rate implies a combination of factors, for example including out-of-spec equipment, is likely involved.
I did really like the discussion of stress balancing. At first glance the "hoop stress" and the axial stress are orthogonal so cannot balance, so it takes some thought to resolve that.
I mean the wheel was destroyed from the collision with the rock. Blaming hookless when there is an opportunity for it
I've got an older set of the rimbrake lun wheels. They are by far the best wheels for tubeless. No spoke holes, tires hold air for weeks, even without sealant.
Thousands of kilometers is done every single day on hookless wheels. Can someone please provide some links to all the accidents happening out there because of the wheels?
Millions, maybe billions... Every car, lorry and motorcycle wheel is hookless...
Great video thanks bro, used your concepts to teach an intro to P=F/A this week
13:21 -- that's not a hookless rim, that's a proper pen!
I'm not a scientist. But I am a lifelong bicyclist. I've seen fads and bad ideas come and go.
As we evolve in technology, dumber ideas seem to be forced on the unknowing consumer.
I hope we are at the pinnacle of dumb ideas. Because these salesman who no longer offer options, are going to be the death of the bicycle industry.
I'm HOOKED on this video
Also my degree in sports engineering specializes in pen functionings
@@paulschulman8131 you mean fuctionings.
19:30 Just wanted to add that even though your cut Winspace wheels which are the hooked example in this video, doesnt mean all hooked rims got a hump (or two, cause each side), so technically this way of failure can still happen with hooked rims. Love the content, just adding info so people don't forget about differentiating and looking into stuff themselves!
My zipps 303s work well for me. Just done a 2000km ultra race. Nothing wrong with the wheelset. Been using sealant and tube on this wheelset. Going down steep mountain, hit pothole and still rolling well.
Congrats. You paid $2K plus for a cheaply and poorly Far East fabbed rim (as proven in this vid) with known garbage hubs to boot. Pat yourself on the back. Well done. LOL 😀😀
@@rcg9573well. I have no issue on the wheel so far. I’m a real user on this wheelset and have been using for 2 years.
At 15:40 in the video, where you show a "gap" (the bead lifted away, or riding high on the rim), you talk about pressure under the bead. I would argue that the pressure pushing upward on the bottom of the bead, is that same no matter how small the gap. If you have 100psi in the tire, the bottom of that bead will have 100psi, even if the gap is almost zero. Thoughts?
That was in regard to "ZIPP Hookless Bike Wheels, A fast track to the Emergency Room!!"
What you said about high pressures is correct. On a smooth surface track pressures are at or near 200psi. But on the road the surface is not flat and incredibly irregular. Hence lower pressures are better on the road. Plus lower pressure help with comfort.
It sure should be way below 200 psi but no, it's not the lower the better.
Dramatic improvements in comfort can also be gained by a decent set of knicks and cork bar tape. Without needing a bouncy rear end and pinch flats or damaged rims.
@@williwacker2774 Veloflex tubular 140psi max. on the road. Veloflex clincher 140psi max. on alloy rim also on the road.
I’ve had DT Swiss GRC1400’s with Vitoria tyres fitted for the last year. Not running at stupid pressures as they’re gravel tyres. However they aren’t actually meant to be fitted to hookless wheels apparently, only realised recently!! Haven’t had a single issue with them though. The tyre is tight AF on the wheel during installation so I’m not worried it’s gonna blow off on a descent. Never say never though.
For me this particular incident appears to be due to too high a pressure in the tyre and/or a heavier rider. Out of interest I wonder if those Vitoria tyres fitted were meant to be installed on hookless rims as a lot of them aren’t. There are manufacturers recommendations etc. interesting topic though. I am not an engineer but I certainly see the common sense side of this debate. Just saying that personally I’ve had no issues with the DT Swiss wheels or any of the other tyres I’ve had installed on them. Only run at 30 psi though so fairly low pressure. Which probably prevents any blow outs etc. For me it’s a happy medium of not too high a pressure equally not too low.
The lip/sidewall on the DT Swiss rim is also quite thick (it’s a carbon one too) and appears to be of good quality and strong. I’ve bashed it hard on big rocks during descents and so far so good. Only had one incidence of a puncture due to a large impact on a rock and that was remedied by fitting a new tyre.
Re tyres; you say Vitoria are sh*te but honestly in my experience they’ve been good so far even though they aren’t strictly meant to be installed on a hookless rim. I run the Terino dry mixed. Good grip. Have lasted long. Don’t seep through the sidewalls (unlike the continentals I’ve had, can’t remember where they’re made but it’s not China. Continental terra trails are now made in China not Germany.
Re Pirelli, I’ve run those with no issue. You also said they are sh*t. This is a company with a rich history in rallying so not sure I agree there.
Re Michelin I do agree with your conclusion great tyre manufacturer who provide good tyres for cars bikes whatever.
Interesting topic. Hope this 2p is interesting!
I'm an engineer and wouldn't touch hookless rims with a barge pole. The manufacturers have a responsibility to consumers to explain the risks.
I’ve got a set of these and had the unfortunate experience of the front tyre blowing off the rim at the top of a big climb apparently the shop sold me the wrong tyres ffs . Now I have no confidence in my zipp 303s wheel shame on them .
90kg and 50k miles on hookless road. I expect that to stay fully trouble free😊
Yeah, you solved a problem that does not exist on the road. Congrats genius. LOL 😀😀
@rcg9573 cool, you're crediting me with creating hookless. When will you start sending me my royalties?
Would be nice if you could explain what the idea behind hookless rims is in the first place. Did not trust them when I saw the first pictures because I was asking where the clincher is supposed to hold to. But what would it require so hookless rims work as intended other than glue-on tubular tyre?
Such nonsense… dudes all freaking out here are clueless. Should hookless rims be a problem, you would see frequent accidents and a class action lawsuit going on for some time right now. To think that Zipp’s engineers wouldn’t do their homework properly and put a failed product in the market, risking the business reputation… please, give me a break. Just follow the guidelines. If you’re too heavy and afraid of over pressure, just get a regular hooked rim and conventional tube tires. That’s it. What a clickbait.
Thank you for the explanation. I ride Mavics along with their tires as a system. No issues but they aren't hookless either.
I love Hambini but he's spewing some BS. I've had hookless rims on all three of my bikes, Mountain, gravel, and road. I follow the guidelines and have never had a problem. I have hookless rims on my motorcycle and car. No problem. According to Hambini I should be absolutely terrified at all times. It's clickbait bullshit. Hambini is better than this.
What I think he’s saying is that there’s a greater risk with hookless not that it WILL fail. I know a guy who smoked a pack a day and he’s alive and kicking in his 80s….
@@MokaBoucha Sure, but the big question is: by how much? If there's just a marginal difference in risk between hooked and hookless eg, than all those discussions are pointless, but we simply dont know (also Hambini doesnt apparently).
If I’m running carbon on road I’m using Campagnolo hooked with continental tires. On MTB I use carbon hookless Chinese rims. I too tried the road lower pressure settings which feel great on flat roads with no pot holes or major road seams but in hilly mountain roads with road imperfections I had a few close calls. So back to more appropriate tire pressures
Hooked shills are the same as rim brake shills. the technology is better but refuse to accept. follow the manufacturers psi and approved tyre list and you wont have a problem.
what makes it better?
To me, it looks like Hambini did not read the chart right. It says there you need a minimum 28 mm tire for the 23 mm rims.
Glad you covered the width. Have to admit I know its anecdotal, but running 28s on a Giant SLR1 which runs the 19.4 internal width on hookless. Havent had an issue such as this on mine, whereas the Zipps are 23 mm
The way you write mu so haphazardly is giving me flashbacks to engineering profs and their uniquely wacky handwriting 😅
With this excellent explanation, I don’t understand why a company would even consider the hookless variation. I mean, if they’re worth anything at all they must’ve at least made the same considerations?
They're cheaper to make. Money money money!
@@marcvb3364 Cheaper, but also the rim is stronger, easier to make precisely, and needs less finishing. Not worth the risk of blowoff, but not purely them being cheap.
Always learn a lot watching these. The bit I'm curious about, isn't there a force in the opposite direction pulling the bead towards the rim because of the air pressure on the other side of the wheel? I don't really get how hookless work if I'm being honest.
Would the flex of the hookless rim as shown in the video at 23:30 be greater than as per design spec given the fact that you have cut the circular rim and thus reduced the tensile forces that only exist when the rim is a whole circle? It seems like your cut away sample is more like the plate form that you mentioned at 17:17 which seems quite different from the full circular rim as designed. Are the hookless rim parts as flexible when the wheel is whole as designed for use?
If this hookless thing was such a problem we would hear more about it long time ago. I think the biggest problem is that people are still putting 8bars in like in old times. My friend is riding 32mm tyre on 7bar and she has 50kg just because bike shop told her so when she bought the bike. When some bike shops are this slow to adopt new tech how can normal rider who just wants to ride know this things? Me and my wife both have zipp 303s and gp5000s tr and they works just fine but we are not some corner divers so we are never near the limit.
hookless literally blow off just sat looking at them with less than 70 PSI, lots of documented videos showing this! What benefit does it offer? Nothing whatsover!
Oh gee, because nobody has ever had a hooked rim and tire fail to seat and then blow the tire off when pumping it up.
But I saw the hookless blow out on the internet!
Agreed. I think there are mistakes been made as regular cyclist and even mechanics at bike shops don't quite know about new tech. A friend had his tire blowing off the rim, he was using a tire not made for hookless rims, and 95 PSI. All of this because his mechanic had no idea this rim required an specific tire. In the Thomas de Gendt case, there was a bloody foam inside.
@davec5615
Oh gee, let’s put a hookless rim on a road bike or a gravel bike to address a nonexistent problem. Whoopeee look at me, my rim is hookless I bought into the marketing BS like a good little sheeple. LOL you clown. 😀
@Hambini Have you seen LightBicycle’s new “hybrid” hook? They advertise that it has a 5psi higher pressure limit for tubeless, but my interest is because it looks like it would be great with tubes - enough hook to act like a hook, but still thick and blunt enough to be tougher in the face of rim strikes. Dunno…
Hambini, I had gp4000 28mm on the back wheel for about 3-4000km. no issues. I installed a (brown wall) GP5000 28mm yesterday and it punctured in 9km!!
Are they shite or was I v unlucky?
well punctures can happen with any tire, however the tan-wall gp5000 seem to be more fragile, teared the sidewalls rather quickly. black walled ones were more solid
@@ElPresidente561 cheers. Punchier was through the black, but It's been OK since.
I was expecting the equations to be populated with typical numbers and the elongation and likelyhood of a tire blowing off a rim to be analyzed. How much pressure does it take to blow particular tire off of a particular rim? And then run a test of the two!
Thanks for trying to keep cyclist's safe Hambini ! Unlike the Cycling Industry Again !!!
Can't remember where I heard/read it, but apparently the ETRTO gave some guidance on minimum tyre size for a given internal rim width for hookless. It was larger than some manufacturers were saying was safe. Probably explains that chart you had up at 22:06
When the rider needs to go by a chart to keep tyres on rims you know there's a serious issue with the hookless design concept.
@@davidpalk5010 completely agree it's a mess. This isn't a tenable situation for a consumer product.
@@adamkenny5673There should definitely be a recall. I worked for one of the pioneer carbon bike brands. We had a recall because some steerer tubes had been made with inconsistent wall thickness, and could therefore fail. The recall was a major factor in the brand's bankruptcy. Brands cannot insure against recall costs, Recalls are very, very expensive to conduct, and a brand's various international distributors may not all be fully supportive and compliant - becasue they are expected to take action for which they will recieve no financial reward. Likewise the retail dealers supplied by those distributors. I was handed the unenviable task of heading up the aforementioned global recall operation. I did my very best, but it was a huge mess and the brand never recovered. Brands which have released hookless rims could very possibly be critically damaged by this.
very good point, not only do hooks secure the tire bead they also resist the stress of the tire pressure. what a bs design hookless is
I remember my biking history -- first department store "road" bike I was riding rocked chrome plated steel clincher rims -- lots of fun braking in the rain. Hookless of course as they had been made that way for decades. I don't remember narrow aluminum hooked rims coming in until the late 70s early 80s, and for safety reasons they were a requirement for the then new foldable clincher tires, which unless you were riding tubulars, they were what you used as a serious cyclist. I can see the modern corporate desire to make things a little easier and cheaper on themselves by eliminating undercuts in the molds like the safety hooks -- just another projected business expense when something goes wrong...
I would appreciate an extra piece on this, appraising what happens after puncturing, and the tyre bead drops into the rim well.
What about (xc-)MTB use? The hook-less edge can be made much thicker. And there for better at dealing with impacts with the ground as a result of the extremely low tire pressures (1 bar is not uncommon). (that is also why mtb use (light weight) inserts; better protection for the rim and side wall support) I agree with you that for road use the pressures (that you should be running) are to high for hook-less and not a option. But for MTB (offroad) lower pressures do result in less roiling resistance and more grip.
I e been using these on my Roubaix for 5 years no issues 70psi. If there’s a real issue lawyers would have a freaking field day
Hookless clincher rims were the standard in the ‘70’s, but as high-performance clincher tires arrived in the ‘80’s, hooked rims (and their ability to hold those tires at their recommended psi) became the norm. So, it made me scratch my head a few years ago when high-tech carbon rims started appearing with “hookless” being a selling point. A weird marriage of high-tech materials with a step back to an outdated design! Kind of like a modern sports car being marketed as having a “technologically advanced” carburetor!
It's not really 'outdated' when it's used for all modern cars and planes, F1 etc.
The sealant ... as a lube 😶 I thought it set up somewhat sealing and holding the beed in place a bit. 2 sets of Zipp 303 S.. tuning 30mm though (one measures at 32mm).
I unknowingly had hookless clicher rims years ago and seem to be ok. Later were not used but after few years I happened to use them and blew tires off (yes high pressure). Had to figure out they were different then all my other rims, I had no idea.