Tank Slappers and the Quest for Perfect Suspension
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- Опубліковано 29 вер 2024
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Is there such a thing as the "perfect" suspension setup? Actually, yes. But it has nothing to do with preload, rebound or compression damping.
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"Like 3 homophobic men, your motorcycle is 550 lbs of pure desire to be straight."
That was not a line I was expecting to hear but I'm so fucking glad I did.
a true example of how to make people feel accepted without disturbing the flow of a great video ^°^
any bike of mine are gay as hell though >:)
That was such a well-scripted line, I genuinely paused the video to see who was discussing it in the comments 😂 Looks like it's also rather underrated.
Why does everyone have to accept people who make their whole identity about their sexual desires!? Why can't gay people just act like straight people and keep their sexual business to themselves!? Why do I have to approve of someone else's sexual desires when it's against my religious beleifs? Why don't my rights matter? Why do my rights have to be trampled for any group to have extra privelege over me? Just leave me alone and I'll leave you alone. Beleive what you want and ill beleive what I want. Im not trying to force gays to accept my identity so why are they trying to force me to accept theirs? Not only accept but affirm!! Im not affirming anything that is against my Catholic faith and is a sin! I'm not perfect but I strive to be. Stop trying to force me to denigrate my own values and religious identity to support your sexual identity. It has nothing to do with hate or homophobia.
@@CantTreadOnMe Chill out dawg it's just a joke, it wasn't aimed at you...
...wait a second
@@CantTreadOnMe So other people have to act differently to who they are in order to fit into your narrow-minded worldview?
Live and let live man. If you don't like someone, just turn around and walk the other way.
Almost 20 years of riding and never stop learning from this channel. Tanks for your work.
I don’t even own a bike, anymore … and still enjoy these videos.
I like to think "tanks" was a puntentional typo. ~RF9
"Tanks" I see what you did there
I assumed tanks was just a child that never learned spell check... Or to wipe their own as.....
As they say in the mechanized marines...
-Bob Gump
Interesting stuff, good video.. I’ve only ever had 1 tank slapper in 33 years of riding, and it’s indelibly printed in my mind! It was under hard acceleration on my ZXR 750 on a patched/bumpy part of the road. The bar oscillation went from lock to lock.. I was genuinely a passenger! Luckily, got it under control and didn’t crash. I had to stop at the side of the road though - to get myself together 😲
Happened to me about 40 years ago on a Honda cbr400, going downhill at about 70mph. I'll never forget that experience. Nothing to do with suspension, more to do with wheel balancing.
Happened to me on an 09’ 1100 Hyper Motard, scared the dogshit out of me, I snatched it up into a wheelie and straightened the bars. I had to take a break until my knees stopped knocking, man what an F’d up ride that was. Be safe fellas ✌️
What level of butt pucker would you say that experience was? 🤔
@@deborahchesser7375what an insane way to save yourself lmao
@@jamespegg6418 same time span on a KZ550 Kawasaki. I tried to accelerate out of it.
LOL,Nope.Just held on tight and slowed down.Wound up selling that bike pretty quick.
I realize you'll never see this, but you're a script genius. It's the main reason I come back. Your content is superbly edited and has gotten (a LOT) better over time. Now I look forward to seeing everything new. Thanks Ryan. Happy 2022 season from Maine US.
Tank slapper has only happened to me one time in my life. I was in Florida on a V-Four Honda VF750F Interceptor. I was going over an overpass and exactly as stated in the video, the front wheel came up. As it planted down again, I was on the downhill and totally unloaded the rear end. It slapped 4 times back and forth then somehow stopped on it's own. I rode 500 feet or so to the gas station where I spent a few minutes thanking all the deities. I had the cheapest tires a 90's young adult could afford, which in hindsight may have saved me the trip to the asphalt.
The "Honda" part of the phrase "V-Four Honda" is likely what saved you. Not that nobody has ever died on a Honda (of course they have), but Honda itself has always had a very strong focus on rider safety and reliable mechanical design - they stake their honor on their bikes because it was what they made for many, many decades before bothering with the car business. The fact that the bike recovered itself so quickly is a testament to their engineering. Meanwhile, you have stuff like the Harley Death Wobble, which comes out of nowhere for seemingly no reason whatsoever (bike moving in a perfectly straight line on a flat freeway), and is difficult to safely recover unless you are at low speed and lucky. I've read that it has something to do with the "rubber mount" design they use to save a few bucks in parts cost and manufacturing, and the only way to eliminate it is with aftermarket parts.
@@martuuk8964 The death wobble is caused by harmonics. It's stupid, but on some road surfaces the slow low end heavy a** cruising long bore v-twin's rocking will line up with the road surface's bumps. And like an extra kid jumping to super bounce another on a trampoline the extra shock at the right time sends the bike's engine off kilter at an unwanted angle into an uncontrollable lift. Thing is, there's no way to know. Engine speed is variable, and the speed the bike is going at to hit the bumps is also variable. It's one of those, "When the planets align the beast shall be summoned forth to lay waste to yon Harley.". And yeah, dampen the engine mount and it mostly gets rid of the problem. Not completely. It's just a basic design flaw of Harley. To get that distinctive Harley sound the engines are slightly unbalanced. No way around it if a customer wants a Harley to sound like a Harley. That sound is a holdover from before precision engineering engines and modern build tolerances. It's why even other cruisers that borrow the Harley aesthetic don't sound like a Harley. German and Japanese engineers won't let anything out the door that's designed unbalanced, they can't even conceive of doing so.
A semester of Suspension theory in 7 minutes! and YES, I would make it perfect if I could (afford it)!
As someone designing FSAE suspension, one thing i realised very quickly, is there IS a theoretical perfect solution, and that's continuous adjustment in real time, if that's unfeasible, there is simply no perfect setup and that's just it. So as long as you're in the ballpark, it's good enough, simple as that. From there tuning the suspension to personal preferences is the only thing to be done and you're as near perfect as it's physically possible without electronics.
@@AntaresSQ01 CDC sounds cheap and easy to DIY from a programmers standpoint
@@PartikleVT Yes but as mentioned in the video CDC or otherwise also known as DDC has limitations. It's very good indeed, and easy in concept to implement, but in practice a lot of man hours go behind designing a reliable system that stays accurate even after hundreds of millions of adjustments. The programming is also difficult behind it as it's making a lot of adjustments, how can it tell the difference between a wheelie on a downwards slope vs the road suddenly dipping out from under the wheel such as riding off a ledge? It can't. To be honest in such a scenario it doesn't matter that it doesn't know because the damping will need to be softened on initial impact and then hardened once the wheels land but there are a few scenarios where it can "trip out". And then accurate BMS units are just expensive, again that have to stay reliable and accurate for a long time. The type BMW uses can register lean angles to 2 decimal points 100 times a second. Don't get me wrong they are entirely feasible to implement, but as we can see, there is a reason the bikes that have them START at 15k (with a few rare exceptions) and most near the lower end actually have very cheap forks with DDC picking up the slack in terms of ride quality. A true high end electronic suspension unit like the Öhlins Semi actives cost 3-4 grand for a reason. Trust me, they aren't making big margins on those systems.
@@AntaresSQ01 I can see how the system gets larger and larger and requires more and more sensors as you start adjusting it.
@@AntaresSQ01 Hi, I have actually designed and patented (US9561701) an active electromechanical suspension that will use the suspension travel to charge the battery. It is even lighter than a standard suspension. I installed a prototype on my motorcycle several years ago and made a video. I have not been able to update the prototype for a while, because I am trying to manufacture an EV (scooter) that uses my other 2 patents, but if you are interested then let me know.
ua-cam.com/video/7J9_Zq-C0d8/v-deo.html
Came for the education, stayed forever for Ryan's brilliant witticisms 😊
As always, thank you Ryan F9 and team for the thought, humor, effort and wit incorporated in these videos. Well done.
The humor is so witty, these videos are totally worthwhile even for cagers!
This channel is a treasure trove of information I did not know I needed and now cannot live without. With each new episode comes anticipation, enjoyment and education. Well done, F9! Bravo!
Even going back as recent as 8 months and you can see how much the video quality increased recently, and this is still brilliant, it just all got, brillianter
These videos are so informative and intelligent.
I often finish them feeling smarter.
The humor in this episode was especially on point!
Well done, well done!!!!!!!!
4:35 Paulo Gonçalves crash in 2016 Dakar rally. He kept going. Died in 2020 Dakar rally.
Never drove a bike since driving licence test, but I really like learning stuff from your channel... great work...
It's almost unbelievable how good your are in explaining basic physics and its application. Thank you!
I had the phone in my hand and I'm still number 6. I guess it shows how much we love his work.
You really should have covered the finale common cause of tank slappers. Out of adjustment or worn out neck bearings.
And the spring rates on bikes with dual rear suspension not matching perfectly (Harley Dyna).
Wheels not weighted properly can also cause them, and on super sports too much weight on your wrists can also cause them as well. I'm especially conscious about this on my r6.
@@Matty_Ice9 Yes, balancing or tires with wear or new poor quality tires can increase chance of it to happen. I had those.
Also totally had forgotten, but in my youth I had a pocket bike - too firm grip would make it wobbly instantly! 🤔 Crazy sensitive steering, would not like that on an bike going over 25 mph 🙃
And mis-adjusted forks in the triples shortening trail too much causing an overly nervous front end
And uneven fork oil levels due to a leaking seal or pitted fork tube
You are leaving other motorcycle channels in the dust. You put in the proper work to create the best content.
4:07 It takes talent to come up with footage like this. Bravo.
Another way to preload the front end is to lower your forks. Not a ton, obviously, but small adjustments can do some pretty amazing things. I rode an R6 for a lot of years commuting. I found the front end too light for around town so I dropped the forks 10mm to plant the tire better. Worked wonders.
This is the best channel it should be the top channel for any rider
I put off everything else if I see a new F9 video. I hope he never stops posting this amazing content.
I’ll never admit that I learn anything from this channel. ✊
Ryan, Ryan, Ryan...
Excellent post, packed with great info as usual. I know your focus here was on suspension issues as the cause of death wobbles, but you did leave out one glaringly huge cause (for most average riders ) far more than accidental power wheelies: Tire balance, wear and inflation. Absolutely, 100% the biggest cause of tank wobbles. Improperly balanced tires wearing uneven are almost a guaranteed tank slapper on the highway, especially if they are at the end of the tread and improperly inflated.
Again, I know the focus was on suspension, but technically tires are part of the suspension as well... Certainly worth a mention.
So true. I had a death wobble, while heavy accelerating, i think due to a new, but defective front tire. Very, very frightening. Before that incident steering with that tire always felt uneasy in corners. Changed the tires, and no more death wobbles since then. And much more confidence in the twisties. I survived the wobble by holding a loose grip on the handles and leaning over the tank ( transferring weight to the front).
My 2011 very modded Mini Cooper uses linear springs. Always know what my suspension is gonna do.
That homophobe joke was gold 😂
Hi Ryan, to prepare you for the Ragley Hall event, please remember that we call the shire here "Warrickshire"! Yes, the 2nd "w" is pronounced as an "r" - coz that's how Shakespeare spelled it. At least that's what I was told when moving here 20+ years ago ...
I'm not even a biking enthusiast and I enjoyed this video.
I especially enjoyed the turns of phrase, especially that 350lb one.
Nice vid.
This surely is one of the first videos every biker must watch.
I know I'm a bit late to this one, but I enjoyed that video, especially as it ended and you mentioned tea drinking watchers... While I was carrying a fresh brew into my living room!!
Citroen has been producing the perfect suspension for decades, it's called Hydroactive.
To bad they stopped making this marvel of engineering in 2018.
Just because steel spring suspension was "good enough" for customers who are now focused on entertainment gadgets.
Yes, it got bad rep for poor maintenance I guess. My dad had 3, I also had 3 and still blame myself for selling the first of those because of "small" issues and it ended up going for scrap.
I never got to the bottom of this, but I think the bad rep was "it leans too much" (older ones especially, but they kept the wheels firmly planted unlike the funny swing axle cars of their time), "it's too soft" (apparently people equate a bumpy ride with sporty aspirations"), but guess what, the moose test speed record is still held by the 1998 Citroen Xantia Activa. And finally, I guess what killed 2 of my 3 Citroens is a terminal hydraulic fluid leak (the first one did too, but I had that one repaired before selling it). But they all had 250.000+ km on them, and then people forget that other cars would have had springs, shocks etc replaced multiple times already...
@@MaartenvanHeek In my family we have had/ has nine large Citroën. 4 CX, 3 Xm, one C5 and the glorius C6. Only once have I had a major hydtaulic leak, it was on an 20 year old CX and was easy to fix by the roadside.
@@Svarthammarholet in my case it was on a 20 yo XM strut return line (fixed same night), second was a Xantia under the (hot) engine block so could not be fixed roadside and had to be towed, by that time including upcoming MOT repairs it was a total loss. Third was a diravi on another XM, after having it repaired 3 times in 3 months I was done with that car, as you can imagine :)
@@MaartenvanHeek In my experience it pays of to find a meccanic that really knows and love these cars if you want to keep them alive and healthy. They are in many ways completely different from all other brands.
And ahh yes the good old Diravi, best ever power-steering in the history of automobiles..
Best MC Channel Of Them All !!!!
Keep Them Coming
I don't even own a motorcycle or a permit to ride one, but I love this channel and have been a subscriber for a while! Keep the amazing content coming!
Outstanding motorbike suspension lesson👍
best ever channel... watching ur channel always.. from philippines Godbless
Yet another entertaining and informative vid! But a minor point I can't help making: The section of the progressive spring with the most coils is the softest part.
Perfect suspension? Yes.
I'd love to float on a magic carpet.
You'd probably lose a lot of feel
KTM motocross/supercross test riders will swear that the air suspension is much better and even pro riders saw how the lap times got faster... but they all hated the lack of feel, which made them likelier to crash so it was abandoned
@@DiegoRuiz1991 I'm not riding on dirt, I'm rounding twisties and cruising down the highway.
@@h.d.h - It's about the same: you need to have enough feedback to never go past what the tyre can endure
As ever Ryan, great content. As a tea sipper who lives in Warwickshire I look forward to catching up with you. We pronounce it Worrickshire 👍🏻
Love your videos, just wish they showed up more in my UA-cam feed.
Old 96 ktm 360 exc was perfect. Light responsive steering, hit a boulder and it stabilised very quickly.
I put a top box on my CB750 in 1976 and it caused tank slappers (even unladen) by lifting the front end with aero drag and wobbling the rear with turbulence. Needless to say, no more top boxes.
I don't know if the Godfather II was weaker than the first one. Top-notch content, BTW. You're way better at what you do than I would ever be.
Great writing... fun and educational. What's not to like? More please
Hi Ryan, I watched this video while sipping tea. I would love to attend the festival in June but my fiancé has booked our wedding for that weekend. When I suggested we move the wedding with just 3 months to go, so I could attend, it went down like a sh!t in a lift! (Elevator for my American cousins). I don’t fancy my chances of “pulling a sicky” either.
Hope you have a great time and get to hang out with TMF, be good to see some footage of you two enjoying all things bikes.
Jolly good video old chap, tally-ho old boy 🇬🇧
The puns are funs in these videos. Another great educational video. We need one on harmonic resonance. Harmonic resonance occurs in a power or mechanical system when the system natural frequency corresponds to the frequency of a source of stimulus (like road bumps).
See you in June! Awesome you are going to be there. I am going to take the bait like a fat trout tho - it’s ‘Warrickshia’ the second W is mute!
Riding stock suspension on a DR650 as a 185 lb dude off road... Yes, I would absolutely love a button to click on perfect suspension.
Props to the driver that kept that bike up,thats some serious adrenaline rush 😂
What the hell? on this video you talked about things i’ve never considered or came up with in my life, great job! 👍
Godfather joke made me spit out my tea. Genuienly enjoy watching your vids so much:)
Great video as always. Might see you in Warwickshire!
Excellent video. Thank you so much! I just got Ohlins suspension on my KLX230 and have been playing around with the rebound damper, as the mechanic set it to be way too slow. I've adjusted it completely the other way, and remembered to come back to this video as a reference for properly adjusting my rebound damper. Cool stuff! Thanks again, Fortnine. Excllent content (:
Yea thanks you are really sharp,appreciate your thorough description
I still can’t believe I don’t have to pay to watch such quality content
Really informative....Tech jargon that I’ve been looking at for years but never really understood :-)
Your channel is always interesting!
Nice breakdown of the causes of the Death Wobble. Bicycles can get 'em if you go fast enough. Mine occurred when I was bombing as fast as gravity would take me down a mountain road in northern Michigan. I was in a full race tuck when a person on the side of the road yelled encouragement. I quickly turned my head to that side and the combo of weight shift and undoubtedly a slight unconscious tweak of the bars nearly smeared me all over the road at 35 mph (which on a mountain bike feels like 85....). Still unsure how I managed to stop safely.
See you at the ABR festival man! Looking forward to it
Fixing tankslappers is easy - don't think you are wayne rainey or kevin schwanz and it's all fixed magically...
Very Interesting, I learned a lot. I was disappointed, however, that you didn’t include a discussion of front wheel wobble occurring when one rolls off the throttle in some speed range, and the front wheel starts to wobble as the weight of the bike shifts forward against engine braking. The rear shocks seem to have something to do with this phenomena, but I’m not sure what.
BRILLIANT, as always. Why wasn`t school this interesting??????
I played with my suspension early last year. Tried to tune my old Honda commuter bike to respond to pavement buckles better at 55mph. Had limited success. Progressive front springs, preload adjustments on rears. My conclusion was that you can't definitively tune for every road condition. Good video!
I was enjoying a nice cuppa when your last comment came on :) Enjoy your visit.
Never had a tank slapper take me down, but felt some serious shaking a few times on rough motocross tracks. Enough crashes in the dirt, hope I never go down on pavement
You get more than just the whole you have to get a bunch of washers and you can put more washers in there to change the rate of compression under stress.
what a fantastic first video to be introduced to a channel.
sub.
Thanks a lot for the explanation.
I knew about shimming but not tank slapping.
For your question: I would not choose perfect suspension. For the same reason I would also never buy a Honda gold wing. Without some gritty roughness motorcycle riding would only be like driving a cabriolet in the rain.
"Like three homophobic men, your motorcycle is 550 pounds of pure desire to be straight."
He has a way with words...
I have come to understand spring rates in kg/mm even as a 'Murican, so you can imagine my surprise when the Canadian starts his explanation with lb/in
My father rode Ex-Cop Harleys in the 50s…/Springer frontends…a High Speed wobble was assured over 90….scary stuff…
I've got an BMW F800 GS with new progressive springs front and rear, max rear preload, forks slightly dropped, and it wobbles down the road at highway speeds while my buddies look on and pity me. It's just too rear heavy to ride anything up front besides an 80/20. It amazes me the problem persists. Just a rant... this was a great video.
Unwelcome cyclic oscillations happen on un-sprung bicycles, too. They seem to be the result of fork trail, rake, loaded weight, tyre dimension and castor effect combining to give the shakes. Some bikes wobble all the time, others once in a blue moon but few are completely exempt, and this is without any suspension. Gripping the top tube with your knees usually puts things right, and the same with the fuel tank on a bike. Theoretically, you can accelerate out of most tank slappers, which is little help if you're heading for a downhill hairpin bend with adverse camber.
Would you?
Depends. Sometime, the compression and rebound are utilized by the rider to control the motorcycle. In cars, it is often referred to as loading the suspension. For those who need a controlled ride, it is probable a great thing. For those who enjoy the personality and integration between man and machine, probably not.
Kinda like a Miata - simple, light, communicative, pleasure.
These are amazing. Just plain amazing. Keep them coming!
legendary once again.
Top tier explanations 🙌🙌
Suspension adjustment has always been one of the nonstop things that I have. Adjust for single, adjust for pillion. Readjust for each ride. Havent found that happy medium
If I could click on perfect suspension, would I? No, I wouldn’t. I like the character of older vehicles. My bike is 14 years old, my truck is 23. No desire to have new, fancy, precise, or perfect. A few years ago I test rode an Indian Scout. Incredible machine, and great respect for what it is, but no character.
Active suspension..I'd say if it could perfectly absorb all road irregularities, potholes, and speed bumps, reduce wear on the bike, limit mass transfer and prevent offsetting the bike's geometry when accelerating or braking, without compromise beetween performance/stability and comfort, without being too heavy, it would be totally worth using a significant amount of energy! I rememeber being blown away by Bose suspension prototype a long time ago. but I would be surprised that it reaches motorcycles first,if it ever goes to production, it will be probably luxury sedans first, luxury GT motorcycles 10 years later and eventually affordable motorcycles 20 years later, like ABS or traction control. but unlike ABS and TC its not just about a couple sensors and a chip, its a complete redesing of the suspension system
A beautifully long winded video that went the whole 7 minutes without saying "Just like, buy a 40$ steering damper, dude."
that was the best starting line ever
Of course I suffered a high speed tank slapper today and now I'm 6 hours in Wonderland. I've had it happen twice and they are scary as shit. I just squeezed with my legs and lean. I ran off the road while still wobbling and the only thing I could think about was the damage I was going to do to my bike. A miracle happened. I didn't lay it down or get thrown. I managed to get back on the road. Once I pulled over I threw my helmet on the grass and the damn visor hinge broke. My Ram mount came off, but it managed to get stuck against the windscreen with my phone still attached.
Sound stuff, bud. Slappers also product of steering geometry, another reason pack down is so dangerous. I've had two lock to lock tank slappers, both when hard on the gas over bumps: Honda SP1 at 130mph and Honda 954 FireBlade at 90. Both unnerving. Strangely, Honda started fitting steering dampers soon after those bikes... Plenty of wobbles and weaves from other bikes, but those were the only two bikes that slapped. I never owned a TL1000...
For mountainbiking, perfect suspension would be super sick.
I would love to meet you. Long ride from San Antonio Texas though. If i had the money and time off work I would make the journey. As for CDC I would like to have it but cost is always the factor.
There's nothing more frightening than watching the (very excellent) UK motorcycle reviews, seeing the oncoming cars going down the wrong side of the road. I feel like I'm about to watch a head on collision, and it makes me have an anxiety attack. The brain can't help but get triggered by seeing a car "in the wrong lane" coming straight at me! haha.
Thanks for your evert very useful video
I'd say no, I wouldn't take that option.
But I know that's only because I haven't tried that option. I'm pretty sure the moment I experience a semi-active suspension set up on a motorbike I'll love it and it will become something that I won't want to do without.
Suffering from CPT for last couple of months.. I think IAM gonna turn on the perfect suspension to save my wrist.
Of course some bikes were just badly designed, and would get a death wobble on any road at certain speeds. My old BMW R65 being one of them, I finally found a partial solution by fitting a rear tyre that had no central groove. Yamaha XS650 (hinge frame) was another, had a mechanical steering damper (which sort of worked). Aerodynamics is another cause, R series BMWs warned you not to exceed 130Kph (I think) if panniers were installed. I think the V4 Honda, the one that had the small front wheel was another such bike.
I've seen that video of the magnetic suspension on that ls400 and it is hilarious they literally make the car jump
0:30 I was not prepared for that😂😂😂😂😂
Just love your videos, cant get enough, I dont want to nitpick, but, when you're talking about progressive springs, the soft end where the whorls are the closest. Just saying.
My MT10 has an electronically activated steering damper. It's brilliant!
I would just relax my arms to let the front end geometry do its job correcting the instability.
I think perfect suspension ticks the box after heated memory foam seating, on the way to autonomous motorcycles. If I wanted all that luxury I'd have a car, maybe a convertible; and I wouldn't even have to wear a helmet!
The feel of the machine, the road, the hyper awareness of centrifugal forces and terrain, traction, foreseeing obstacles and standing up on the pegs or maneuvering around them.. I enjoy this, and I would hope most people find the discomfort and challenge appealing, on a bike. In my experience tank slappers are usually a result of going too fast on too poor of a road, or doing something more obviously stupid. You can only build something to be human-error-proof so much until it starts to drive itself.
Would I? Some of my most memorable moments have involved slappers 😎
There is also one other reason, bike frame stiffness and geometry. My first motorcycle was Yamaha XJ600 Diversion and it would have diverted out of control very quickly if both hands where not in bars. It is famous for tendency to start wobling.
Yes. Wouldn't mind if they replicated the ride of a '75 Fleetwood Cadillac in a bike that could handle an emergency stop. I'd buy it...
Fascinating video!
Been riding for long time, the new generation of motorcycles are amazing, even the one with no electronic aids… you dont go to the forest hoping to have internet service an cable … do you?
Always great content!