Apologies for some autofocus issues with the camera. Not sure what happened there. Maybe Sony just dropped $20K on a disc brake bike - LOL. Also, SilverFox project is next week. Stay tuned. Exciting results there too. Cam
Mister Camshaft sir, I has a thinks of possible cause for noticeable discrepancy... 11 and 12 speeds. If both horses have same sized cranks and are (saaay) 11-28 cassettes there is the chance to be in a tooth or two inequality during tests 1 and 2. So whilst power might have been held was cadence? [was cadence recorded too, that should show up]
Mate, I appreciate your efforts but there are too many variables with your bikes and testing methodology. The aero differences between rim profiles could have a greater effect than the brakes, so build a combo wheelset with center lock disc hubs and brake rims. Add or remove the brake rotors when swapping wheels between bikes. Replicate riding position and biomechanics on both bikes (same crank length). Do identical chain prep on both bikes. Eliminate test surface variability by doing all testing on a velodrome, preferably indoors. Differences in aero drag will be greater at higher speeds, so test at higher speeds. Instead of measuring average speed, create a scatter plot of velocity vs watts. If there is a difference between the bikes and you have enough data points, you will see a trend. Don't try to quantify gains from lower weight or rotational inertia with a 2 bike test, that is better done by adding weight to a single bike.
Come to Adelaide and you can use my SL8 sworks tarmac. It’s just gathering dust at the moment. I prefer my SL2 by far. Lighter, stiffer, stronger, quicker, better to service and fit. SL8 sworks tarmac is the best bike in disc land but still about 15 seconds slower up Norton summit than a $700 sl2 off facebook. Same watts.
Cam, I have an Sworks SL6 rim (54) and a Specialized SL7 (54) and live local (Brisbane). You could grab that SL8 (54) on Alchemycycletrader and do a 3 way. Now who wouldn’t want a 3 way 😳……., and the cogs start turning.
Extremely kind offer Gary, so thank you. However, I’m simply not comfortable with taking someone else’s equipment, changing things around to fit me properly and then riding it. There’s always risk of damage and things not being put back the way they came…I don’t want to be responsible for that nor put that risk on anyone. I am very grateful for your offer though. Appreciate it.
I have both rim and disc road bikes. I go back-and-forth with riding them. Being a 55 year-old cyclist with where I ride and how I ride I don’t need the power of disc brakes. I do like the simplicity of rim brakes, but I’ve never had an issue with hydraulic disc. I do like the advantage of the disc for running wider tires. If manufactures made rim brake frames to accept wider tires that would negate one of the advantages of disc.
@@petersouthernboy6327I don't see how that could be a difficult task though. There are so many weird caliper designs, from ultra lightweight to aero TT specific. Surely designing them with wider tyres in mind can't be such a headache
@@richeeg3271 it would take a niche aftermarket manufacturer like Cane Creek to do it. No OEM is going to make that investment for quite practical business reasons.
My ultegras (whatever the last cable ones were) are taking tyres measuring 30mm too. 28s on wide modern rims and 32s on narrow rims (both come to 30mm). I think the wider rim could go up a size too because of how it shapes the tyre.
You should check out a 2022 Giant TCR KOM (RIM) vs a 2022 Giant TCR Advanced(Disc). That way you're testing the same generation of bike. They're the same geometry and identical frames the disc version even has the rim brake bridge. You could then do a circuit that involves climbs, descents and flats to see what bike is faster with the same avgs watts. Interesting results all the same. Nice video.
@@francescosaturnino113 but there were some differences in rider position, he said the bars were slightly narrower on the disc which for a rider his size would easily acount for a few seconds difference. Cam's testing also seems a lot more thorough by using different courses. PT just went back and forth on the same section of flat road which effectively removes the extra weight of the discs from the equation. I'm sure if Cam tested those 2 frames with the same bar width it would be a similar result to the BMCs.
I don't think that is the best idea. It would be interesting, and I would watch it. But, those bikes are a compromise one way or another. Bikes designed around disc brakes take advantage of it while bikes designed for both, or for rim brakes but adapted to disc brakes, will have limitations.
This is really interesting. Also as I am thinking about building a rim brake "old school" bike . The margins in your test is very small and for me the conclusion is that the old bike actually can keep up with the modern very expensive bike . Thanks for the good work
Excellent video! The amount of attention to detail for this test is amazing. I often do my own little comparisons between my rim brake road bike and my recumbent but not nearly as in depth as this.
As an average rider and way below average descender, I think the biggest benefit of disc breaks is the confidence they give me on long, steep descends. I therefore think that disc bikes will win in technical descends. I can go much faster and break later to make it round the next hairpin. However, the associated disadvantage is the potential lock-up if this is taken over the edge.
It makes sense that rim brakes are slightly more aero. But one of the advantages of disc is ability to fit wider tires, be able to run them at lower pressures and be more comfortable which makes bumps take less wear and allow you to go faster longer. Either way I think it doesn't matter that much ride whatever you prefer. Better nutrition and training will out do any of these small gains anyway.
"more comfortable" is widely used in ads and a term you can´t measure because everyone has his own feelings. i have ridden on the same bike with stiff alloy frame, on the same roads from 37mm schwalbe marathon/marathon racer, 35mm Kojaks, 35mm Conti Grand Prix Urban, 35mm Challenge Strada Bianca. 32mm Conti Speed, 28mm Conti 4k, 25mm Pirelli P Zero and 23mm Michelin Power Cup Competition. all with a wide range of pressure. at the end the 23-28mm was fastest very consistent. and the bike was always at the lightest that way. how much more comfy was the 35mm ones? a bit more but not world changing. running them high on pressure, but still withing range, all of them are quite hard. the best in comfort was the Strada Bianca. very plush feeling. if time and performance doesnt matter that much, 32-35mm is a nice size i highly recommend.
this is mainly due to new bikes being made with more tire clearance. and since only few new frames are rim, quite a few older frames have less tire clearance. 28mm rims are officially supported by all recent rim brakes and some people have found brakes that can take even 30mm wide rims.
I know someone with that 2013 BMC rim brake bike and it is a genuinely fast frame - I don’t think that current BMCs perform as well these days… ideally your best comparison would be same model rim/disc. Brave to go there Cam 😂
Agreed, I'd love to see a SL6 disc vs SL6 rim brake comparison for this reason! Really comparing apples to apples :) you wouldn't have the aspect of different geometry etc...
I’ve got a 2012 Scott addict that I’ve just upgraded to SRAM Red 22. Unbelievably light and fast race machine. Good brake pads and never had a problem with stopping, I really don’t see a need to change to a modern machine any time soon.
Thanks for doing this Cam. I think the work you did ahead of the test making the equipment as close to identical as possible made a big difference. I was expecting the modern bike to be faster so to see this is significant. I think if you compare a rim brake SL6 with a disc brake SL8 the result will be similar.
Hey Cam, I have been VERY tempted make a video and put my Sworks SL6 rim up against a SL8, because I thoroughly believe my SL6 was the fastest bike Specialized made, possibly the fastest climbing bike ever made. Its basically an SL8 but lighter and more aero due to the lack of rotors.
Thanks for the vid, im hanging on to my 2010 Dura Ace equipped Merida Scultura now, no need to change if its just as quick as modern bikes. Just a thought, hope you can respond to this Cam. The rider produces by far the most drag, aero frames in comparison give marginal gains. Most modern aero bikes have a lower stack height, and put the rider in a more aero position with a flatter back and so less frontal area. I would ague when other UA-camrs have tested modern aero bikes and compared them to older rim brake models, it is the body position on modern bikes that makes them faster when they test them. You have replicated the body position on both bikes you tested, so it makes it a more level playing field.
I had the opportunity to grab a SL6 Ultralight, but I already own the other most coveted rim brake frame, the Supersix Evo Black. One day I'll grab one
Identical geometry would be best obviously. Body position should be identical between each bike. Otherwise making them identical is totally inaccurate because it's ignoring the advantages disc frames have which is the entire point. Wider fork blades isn't just for wider tires but it's more aerodynamic keeping the fork blades away from turbulance off the tire. Something you can't do in a rim brake frame because you need the rim brake calipers to be closer. The disc brake rim profile should also be optimized to be as aero as possible in both rim width and shape since you don't need a brake track or a narrow enough width to work in a rim brake caliper. While tire construction should be identical that doesn't mean the width should be if using the wider clearance available on the disc bike means you can get a faster combination than the tire width you can fit in a rim brake bike. If you aren't exploiting the advantages that disc has then you're knee caping the entire point of performance gains. Potentially down grading it to the limitations of a rim brake bike. It would be like adding weight to the rim brake bike so you have a "fair" comparison with the slightly heavier disc bike. Personally, I don't think there's going to be any statistically significant results one way or the other. Body position, good fitting jersey, having a clean drivetrain, good tires and good bearings makes up the overwhelming majority of performance. Everything else is so minor it's extremely difficult to measure outside of a laboratory setting.
I did the same recently. Changed my “modern” disk brakes di2 bike by one S-Works SL6 Di2 Rim brakes. From the change, a new Personal Record in strava every day! In climbs and also in downhills. Why ? I don’t know, both bikes are very similar in groupset, wheels, etc
Great video Cam! Rim brake bikes are better on every aspect, people should start thinking with their own head instead of formatting themselves with marketing commercials 😜
Great to see a review of the Rim v Disc bikes that makes a good attempt at isolating the difference between both bike types… (unlike others in Australia whose findings pushed disc brake gains using completely different bikes types). Apart from the performance gain with rim brakes and weight advantage shown in the video, the rim brake bikes are much easier to live on a day to day basis with due to the ease of required maintenance of rim brakes and much lower cost life cycle costs … which makes them a clear winner for me …. Especially on road bikes and given 99% of my rides are in dry conditions
Yep. When riding in a group that small difference isn't going to matter since almost everyone is drafting anyway. And if it is raining, where disc brakes seem to have a slight advantage you aren't going to be riding like an absolute madman anyway.
I have two CAAD10 and 3 Supersix Evos, all rim brake. The latest Evo would be faster, just because of aero and big tires. Still love my Cannondales though
@@heinik4349 bigger tires are faster. On the rough roads that are more and more commonplace, they roll faster. Current Evo is 15 Watts faster at 40 kph. I'm faster on my old Evo than my CAAD10 on any acceleration or climb. That said, there's a 4 pound difference between my bikes, same size and fit
Cam , mate , brother , I just was at my lbs and they have that teamachine same paint , 54 with 105 hardly rode . 2k USA$ here in Seattle and i nearly bought it on sight . I ride a 2014 izalco pro 10spd ultegra , few wheels , sl45s 28mm conti or 26mm pirelli, nothing new but it's great as I'm 55 . I do want more speed and this helped
Great vid! I find myself riding rim brakes more and more as well. I'll probably sell off all my disc bikes next spring and spend it all on gucci steel bikes.
Good video, love your style. For the conclusion you mentioned that the body position could have been different from the bikes. I think Niel could have helped you to check the position to minimize the difference between both bike positions
Thanks for the great video Cam. I don’t think your testing with these bikes are done. You’ve evaluated the differences well between frame/brake systems on climbs and flats using mostly controlled wheels and tyres. Now we have a picture of how weight and geo makes a fast bike. What I would love to see is how the modern bike allows us further advantages (wider tyres and wheels), that the rim brake bike just can’t afford us. I would love for you to test maybe the same brand of wheels and tyres on the disc bike, except with wider tyres and wheels, as that is the main advantage and trade off with the heavier bike. Maybe test them both on smooth and rough roads just to see if theres a course specific bias to the bike platforms. I do think modern bikes with wider tyres are advantageous for most people, as smooth roads are not that common. This is coming from a Rim brake bike rider (2010 and 2018 rim brake bikes).
Its all well and good until you're riding in the wet and raining weather of Northern EU. Sure if you're in Denmark or NL where it's flat (Limburg is an exception). But we all know that this environment is pretty much the fairest of weather...and doesn't represent everywhere else. Also long term, if you aren't somewhere flat and dry..enjoy replacing your wheels after you wear through the carbon rim. But it is a good fair test, I admit that, but sometimes the controls aren't really controls because in the real world, controls go out the window.
You’re a funny bugger Cam. Great clip and content. I use to own an S-Works SL6 Tarmac, before I got the 2023 SLR01 and so I’ll be keen to see how the next project goes. Keep putting out these reports Cam. Always interesting 🚴🏼🤙🚵♂️💪
Loved the concept and the resultant video. Yes please try to replicate with other brands. I would expect the heavier setup to roll further down a hill.
No, no rim are worse. You must using more power in hand to braking, and with carbon rims they are many many problem with rim brakes. Disc brakes are ahead of any rim brakes, and are very ease to mainetance.
Don't argue with durian. He's a full blown troll who is in a sketchy relationship with an internet whore, not gonna win that argument mate. @@Pablo_Coach
@@Pablo_Coach You would need a good carbon rim wheel set like the Winspace Hypers to adjust for your describes problems. Go to Reginald Scotts channel and watch his 30min deepdive on why rimbrakes are better. Any Durianrider Video on that will also do. If you think that disc brakes are better to maintain you are just delusional my friend... Sorry to brake (pun intended) to you.
@@franzkohlack8336 BS. Any Carbon rims are delaminated with that high temperatures on descends, and need More power on levers (with disc brakes I use one finger only)
Fascinating. I speculate that the stated measurements of the two bikes might be different than the actual measurements, but you'll need some fancy jig to figure that out.
I would love to see more of these comparisons of rim vs discs! However, I am sure most bike companies would not as it goes against the narrative most bike brands are pushing today. And yes I am a BIG fan of rim bikes but do own a disc one. Rim for fast days disc for long days.
The bike industry and the people who support it, deserve more of this independant research. I would love to see a pro use a rim brake bike for certain stages in the tour in 2025, purely because theres no argument against it being faster.
I've had a custom steel rim brake frame built using 1'1/8 tubes except for the rear stays. I had been riding a SL6 Domane (2017) Disk bike and although a great all day ride I was always concerned with the tube diameters, the down tube in particular. The down tube here is getting on to be nearly three times the width of the steel tube, so any claimed aero profiling of the Trek tube would have to be nearly 3 times better than a cylindrical shape. It is actually wider than it is long... so that doesn't seem to stack up either. The steel bike rear brake cable pops in and out of the top tube and I went sram axs on the build so I did not have to run any other cables, so it is fairly clean from a cable perspective. Basically a classic looking steel frame with modern parts. It is an absolute weapon compared to the TREK. It is probably an unfair comparison, but I have certainly noticed that most of the tour bikes have much skinnier tube sets/frame than what they were riding say 5 years ago. A think like for like, rim brake frames will probably be more aero and lighter than disc brake. In a dry climate it would be hard to justify Discs, but like me, when it is wet and cold with grimy roads --- I still take the Trek--- with full mudguards!
Great video, been waiting for this. Durianrider is the GOAT. It's why iv'e just bought an S-Works Roubaix SL3, it rides amazing. The BIG difference which you're not even mentioning is the price of course, which makes this choice an even more no-brainer.
Last month I asked a friend of mine, who has ridden for a couple of world tour teams and is still racing in Europe on a pro team, what was his favorite bike and his least favorite bike of all the bikes he has ridden. Here is what he replied; "I think my favorite bike so far was the Giant TCR. It was light and handled really well, I could immediately descend better on it. And it’s less expensive than a lot of other high end bikes. I always thought the BMC road bike drove like a boat. Even after 4 years I never felt great on it. But their TT bike was the best " BTW, who in the world changes wheels by turning their bike upside down like that??
Thanks for the confirmation that I don't need to get a new bike any time soon, still love my 2018 rim brake trek emonda. I'll stay away from wallet weight savings a little longer
Excellent video. Ive been asking Norcal to do something similar for months. So can we assume that Jessies claims on the Niel Millar show that a new aero bike is at least 20 watts faster be classed as bollox. I can also recall Chris Horner stating on one of his channels that when he finished Trek wanted him to do a commercial stating that the new Moadone was x watts faster, Chris stated if it was x watts faster he would still be riding the world tour 🤣
Interesting video Cam! Big fan of BMC, disc brake and rim brake bikes. I have a 2008 cervelo which feels fast and very light to this day, but is noticeably less comfortable over time and i'm less confident on descents than my 2020 BMC teamachine with discs. The extra weight does go somewhere for performance but it's hard to demonstrate that with tests out on the road. Something to consider would be a "sketchy" decent test, but it would be hard to show differences aren't related to bike handling. Another thing would be spin down test of the wheels to show the bearing resistance is the same. Qualitative experience about the way each bike feels during each test is also scientifically valid, I'd be interested to hear what you think in terms of bike feel, vibration, stiffness in sprinting and cornering etc. Thanks for the interesting video!
Nice to see more tests on this (long debated) point of contention. I guess the million dollar question for you is ... now that you seem to have shown its faster , are you going to be riding that 2013 rim brake BMC from now on or are you going to stick to 2023 disc brake version and why? EDIT ... I took a look at few online calculators. Based on those and holding everything else constant (and using some assumed other inputs calibrated to the faster run). I see the following for a 3.6% climb ... 400g of weight for the uphill test is a bit less than a 1s difference ... a 5 second difference over the climb is equivalent to about 14 watts.
What I was curious to know, is how did each bike feel in each type of test? Speed is one thing and it's very interesting to see those results and I appreciate the effort, time and money you put into these tests. Maybe a video on how each one felt to ride each segment, the pros and cons of each would make for an interesting video. I own disc brake bikes and I love how they stop but I also love how the rim brake bike feels when I ride it, it's more responsive and nimble and just feels more spritely if that makes sense. Of course I don't have the same model in disc to do a back to back comparison though. On the forums when someone rides a Ritchey Road Logic rim brake and a then a Ritchey Road Logic disc brake, effectively the same bike apart the design changes due to breaking types everyone says the rim brake feels more lively/springy and enjoyable to ride over the disc brake which feels like, to quote one person "like a pig" which could be attributed to the reinforcement to cater for the disc brakes.
I’m very intrigued to see the results of the specialized vs bmc if you were able to make it happen….best of luck on this new endeavor awesome video like always
Great video, Cam. Balanced, transparent and honest. And as a bonus, rim brakes came out on top and we had an interlude from everyone’s favourite vegan.
Interesting test and good work, i know these are time intensive. My conclusion is that the rim is faster for this bike because the frames are both conventional design. All other things being equal, rim is lighter and faster. However, I do believe many modern bikes that emphasize aero are faster. There are frame designs that didn't exist in rim brake era.
Cam, another very interesting series of test outcomes. Real world back to back tests are hard to find. Perhaps if you carried the extra 235gms in your jersey pockets (hidden from aero influences) on the 2013 bike as a comparison, we'd know more about aero, etc. Extra mass should make your rolling distance greater, momentum does matter, after all, just as it makes climbing slower, even on slopes below that 'magical' 7-8%. If mass is different, what can the results actually show us? I've always wondered why pros don't add 2 bottles at the top of each climb before a long descent. So, my 61cm 2018 RCA @ 7.2kgs with 45mm/28mm OD aero wheels/tyres, aero bars & a slammed -20 stem with Tri-Rig brakes could be faster than a current R5 with discs & Di2? These tests do of course open up the chance to test climbing bikes vs aero bikes, an R5 vs an S5 perhaps? I love my rim-brake bikes, but I'm not so certain the marketplace does, unless buying a cheap rim-brake 'old-school' bike becomes a thing for many others, too. 🤔
Cam, great effort in getting high quality data! I believe the climbing speed difference is very significant, at 2.5% = 5 seconds/200 seconds. I strongly suspect the differences you measured are real. But, as much as we might want to draw a conclusion that rim brake bikes are faster while climbing etc., we simply cannot do this. Even if somehow every other aspect was truly identical, which it isn’t because that’s essentially impossible, there’s always the potential for some unknown error. This of course is the reason that scientific tests, which this is, have to be independently reproduced by others. Just as you brought up at the end of the video. Just looking at the climbing data, something doesn’t add up. The disc brake bike is 235 g heavier. I’m estimating the total weight is around 110 kg. So, this weight difference is only about 0.2% weight difference. So, weight couldn’t possible explain the 2.5% in climbing speed. If we then look to aero difference to explain this, I get some back of the envelop estimates that using the rim brake bike would have to be about 8% more aero (8% lower CdA). There’s simply no way the rim brakes are going to be 8% lower total CdA. We know the rider dominates the aero losses. Also, other testing I've seen shows aero differences are very small to non-existent between rim and disc brakes. So, if there really is something in the range of 8% aero difference, it’s not going to be due to the rim brakes vs disc. It pretty much would have to be rider position. My point is not to poke holes in your efforts. Getting good data, which you have done, is very hard to do and takes a lot of time and effort. For those who have never done this type of testing, it is much harder than you think to do it well. I just don’t think the majority of the difference, at least for the climbing test, can be attributed to rim vs disc brakes. I think there’s something else going on. Cam, thanks again for this effort.
Strongly agree, I tried to estimate the difference needed in weight assuming a constant efficiency, for a 3.6% slope over a distance of 1.47 km at 353 watts, using the formula P=m⋅g⋅v⋅sin(θ)/n. and it would require the bike-rider complex to be 3 kg heavier to explain a 6 seconds time difference. So there must be something else going on here. Would be curious on Cam's hypothesis on this
I am getting tons of these videos recommended to me and I suspect it is a hidden agenda to drive more consumer cycles by making us all think we need a new bike again and have to buy rim brakes now.
The wheels are different. Creative Classic Disc 45 has an internal width of 21mm, the rim brake version is only 19mm wide. The measured width of the tires on the disc bike should be wider, in turn the tire pressure should be lower to get the same rolling resistance and vibration absorption.
The only way to get consistent watts is to use an electric motor. A power meter is great but for such a test with small differences it might not be the best tool for the job.
I bet Durianrider would lend you his SL8 😉 great idea to compare other makes.. what about Cannondale supersix evo 😊 excellent vid Cam as always dude.. Pete 🚴🏻👍
Good work on the test. Clearly a lot of work went into it. There is a 235gram difference between the 2 bikes, circa (3.4%), but both under UCI 6.8kg weight limit. Would it be fair to bring both bikes up to 6.8kg? Possibly a waste of time, given people's entrenched position on the subject. Your patience with the green shirted rim brake warrior was admirable.😂 I am lucky enough to have both rim and disc brake bikes in my stable. I do prefer the disc brake bike when going down hill, shimano ulterga, having said that the rim brakes (sram red) performed very well this summer when going to a steep hill and I was confronted with a car on the wrong side of the road. Under this test, I can reveal that adrenaline is brown
I don't road bicycle I'm only an amateur mtber but I drive fast cars and what is one of the things you learn when you track race : unsprung weight matters a lot, what is unsprung weight ? pretty much the wheel IF on a rim brake bike or the wheel + brake disc on a disc bike that's what you're seeing here and why I absolutely love my car smaller winter tires mounted on lightweight Oz wheels and hate every spring when I mount the heavy sluggish oem summer wheels even with a whole car between the wheels and me I can feel the difference so on a light bike powered by your muscles for sure it has an impact
Apologies for some autofocus issues with the camera. Not sure what happened there. Maybe Sony just dropped $20K on a disc brake bike - LOL. Also, SilverFox project is next week. Stay tuned. Exciting results there too. Cam
Cam how did the bike feel on Saturday ride?
Mister Camshaft sir, I has a thinks of possible cause for noticeable discrepancy... 11 and 12 speeds. If both horses have same sized cranks and are (saaay) 11-28 cassettes there is the chance to be in a tooth or two inequality during tests 1 and 2.
So whilst power might have been held was cadence? [was cadence recorded too, that should show up]
Mate, I appreciate your efforts but there are too many variables with your bikes and testing methodology. The aero differences between rim profiles could have a greater effect than the brakes, so build a combo wheelset with center lock disc hubs and brake rims. Add or remove the brake rotors when swapping wheels between bikes. Replicate riding position and biomechanics on both bikes (same crank length). Do identical chain prep on both bikes.
Eliminate test surface variability by doing all testing on a velodrome, preferably indoors. Differences in aero drag will be greater at higher speeds, so test at higher speeds. Instead of measuring average speed, create a scatter plot of velocity vs watts. If there is a difference between the bikes and you have enough data points, you will see a trend. Don't try to quantify gains from lower weight or rotational inertia with a 2 bike test, that is better done by adding weight to a single bike.
Love that Durianrider made a guest appearance.
haha not a perfect cameo, still had a jersey on!
LOLZ 😂
Should have had the naff "govegan" vest in shiite brown and lime green
Was gonna post the same hahaha
Doesn’t Durianrider own a SL6 and a SL8?!? 🧐
Come to Adelaide and you can use my SL8 sworks tarmac. It’s just gathering dust at the moment. I prefer my SL2 by far. Lighter, stiffer, stronger, quicker, better to service and fit.
SL8 sworks tarmac is the best bike in disc land but still about 15 seconds slower up Norton summit than a $700 sl2 off facebook. Same watts.
Make it happen Cam! Make it the most epic vid of 2024 get and maybe together with Jesse and Chris haha
@@franzkohlack8336 Jessica and Christina are 2 drama queens. We don't want them
How can SL8 be the best disk brake bike? You said it was floppy junk with an unreliable steerer tube design.
@@devdroid9606facts!!!! @durianriders
@@devdroid9606 of all the other disk brake junk bikes, he meant that's the best one out of them
Cam, I have an Sworks SL6 rim (54) and a Specialized SL7 (54) and live local (Brisbane). You could grab that SL8 (54) on Alchemycycletrader and do a 3 way. Now who wouldn’t want a 3 way 😳……., and the cogs start turning.
Thumbs up
Can't beat that Offer
Same here, got a sw sl6 rim and a sw sl7 on enve’s 5.6/4.5 2022 The sl6 is more fun and the sl7 faster imo.
Extremely kind offer Gary, so thank you. However, I’m simply not comfortable with taking someone else’s equipment, changing things around to fit me properly and then riding it. There’s always risk of damage and things not being put back the way they came…I don’t want to be responsible for that nor put that risk on anyone. I am very grateful for your offer though. Appreciate it.
@@CamNichollsI’ve got an SL8 sworks tarmac that’s gathering dust now I don’t even use it for a shopping bike.
This was a lot of work and variables controlled as much as possible. I don't see anyone else doing this at this level.
I have both rim and disc road bikes. I go back-and-forth with riding them. Being a 55 year-old cyclist with where I ride and how I ride I don’t need the power of disc brakes. I do like the simplicity of rim brakes, but I’ve never had an issue with hydraulic disc. I do like the advantage of the disc for running wider tires. If manufactures made rim brake frames to accept wider tires that would negate one of the advantages of disc.
Well, it might also require the caliper manufacturer to make wider brake calipers
@@petersouthernboy6327I don't see how that could be a difficult task though. There are so many weird caliper designs, from ultra lightweight to aero TT specific. Surely designing them with wider tyres in mind can't be such a headache
@@richeeg3271 it would take a niche aftermarket manufacturer like Cane Creek to do it. No OEM is going to make that investment for quite practical business reasons.
well my dura ace 9100 brakes fit 30mm no problem, how big do you want your road tires?
My ultegras (whatever the last cable ones were) are taking tyres measuring 30mm too. 28s on wide modern rims and 32s on narrow rims (both come to 30mm). I think the wider rim could go up a size too because of how it shapes the tyre.
The results don't surprise me in the slightest.
Thanks for doing the hard work Cam!
You should check out a 2022 Giant TCR KOM (RIM) vs a 2022 Giant TCR Advanced(Disc). That way you're testing the same generation of bike. They're the same geometry and identical frames the disc version even has the rim brake bridge. You could then do a circuit that involves climbs, descents and flats to see what bike is faster with the same avgs watts.
Interesting results all the same. Nice video.
I think peak torque did that (not 2022 model, but both were the same model). He found no significant difference between the bikes.
@@francescosaturnino113 but there were some differences in rider position, he said the bars were slightly narrower on the disc which for a rider his size would easily acount for a few seconds difference. Cam's testing also seems a lot more thorough by using different courses. PT just went back and forth on the same section of flat road which effectively removes the extra weight of the discs from the equation. I'm sure if Cam tested those 2 frames with the same bar width it would be a similar result to the BMCs.
I don't think that is the best idea. It would be interesting, and I would watch it. But, those bikes are a compromise one way or another. Bikes designed around disc brakes take advantage of it while bikes designed for both, or for rim brakes but adapted to disc brakes, will have limitations.
Thanks for doing such a thorough comparison and for trying so hard to make it a fair one.
You should drop some money on upgrades to the rim brake one and get it even faster. ;) Still cost less than the disc brake one too.
True perhaps. However, until the mystic rim brake speed-sauce is disc-overed, it isn't broken so why try and fix it ;)
That’s interesting. Since there is probably more room to improve the rim brake than the disc brake one.
@@lucasherculano5563like putting on better brakes?😀
This is really interesting. Also as I am thinking about building a rim brake "old school" bike . The margins in your test is very small and for me the conclusion is that the old bike actually can keep up with the modern very expensive bike . Thanks for the good work
Cam The greatest. Waiting for The s-works tests 👍👍
Great follow up video, thanks for sticking with it!
Very brave to post this
Thanks mate!
Colnago and Time both do disc and rim brake versions of the same frame. Test them.
This is a great idea, but these frames are even more expensive than the Specialized ones.
@@krider7296 The Colnagos maybe, not the Time.
crazy that durian rider came up to a sunny coast crit track to yap on about his golden years.
He had no golden years .. he was aty best a C grade rider in Adelaide apparently
golden years?
@@cannon1156A grade. Did a few NRS races. Still have second place on the hardest sub10 min KOM in SA.
Your turn😂
@@durianriders maybe when you were using the drugs
@@mettflow2648 golden drug use?
Thanks Cam, appreciate the HOURS you put in to this video.
Great vid. Appreciate all the testing between rim & disc. Lots of lol’s as well. Keep it going!
Thanks for doing these tests AND throwing away the litter!
Finally ! I've been waiting for this video for a long time.
Thank you !!
Good impression of DurianRider, but you forgot to say to carb the F up 🤣
Loved this type of content....need more of it!
Excellent video! The amount of attention to detail for this test is amazing. I often do my own little comparisons between my rim brake road bike and my recumbent but not nearly as in depth as this.
As an average rider and way below average descender, I think the biggest benefit of disc breaks is the confidence they give me on long, steep descends. I therefore think that disc bikes will win in technical descends. I can go much faster and break later to make it round the next hairpin. However, the associated disadvantage is the potential lock-up if this is taken over the edge.
I think locking up disc brakes is less of a risk than rim brakes failing or overheating the rim.
It makes sense that rim brakes are slightly more aero. But one of the advantages of disc is ability to fit wider tires, be able to run them at lower pressures and be more comfortable which makes bumps take less wear and allow you to go faster longer.
Either way I think it doesn't matter that much ride whatever you prefer. Better nutrition and training will out do any of these small gains anyway.
"more comfortable" is widely used in ads and a term you can´t measure because everyone has his own feelings. i have ridden on the same bike with stiff alloy frame, on the same roads from 37mm schwalbe marathon/marathon racer, 35mm Kojaks, 35mm Conti Grand Prix Urban, 35mm Challenge Strada Bianca.
32mm Conti Speed, 28mm Conti 4k, 25mm Pirelli P Zero and 23mm Michelin Power Cup Competition. all with a wide range of pressure. at the end the 23-28mm was fastest very consistent. and the bike was always at the lightest that way.
how much more comfy was the 35mm ones? a bit more but not world changing. running them high on pressure, but still withing range, all of them are quite hard. the best in comfort was the Strada Bianca. very plush feeling.
if time and performance doesnt matter that much, 32-35mm is a nice size i highly recommend.
this is mainly due to new bikes being made with more tire clearance. and since only few new frames are rim, quite a few older frames have less tire clearance. 28mm rims are officially supported by all recent rim brakes and some people have found brakes that can take even 30mm wide rims.
“But mu fatter tyres!” Grade A disc brake cope. 😆
Can confirm Michael at Creative is a legend. His wheels are excellent!
I know someone with that 2013 BMC rim brake bike and it is a genuinely fast frame - I don’t think that current BMCs perform as well these days… ideally your best comparison would be same model rim/disc.
Brave to go there Cam 😂
Agreed, I'd love to see a SL6 disc vs SL6 rim brake comparison for this reason! Really comparing apples to apples :) you wouldn't have the aspect of different geometry etc...
That old school BMC is just a classy bike. Side profile is 🤤
I have one for sale 58cm XL
I’ve got a 2012 Scott addict that I’ve just upgraded to SRAM Red 22. Unbelievably light and fast race machine. Good brake pads and never had a problem with stopping, I really don’t see a need to change to a modern machine any time soon.
Thanks for doing the hard work Cam! You are are real bike nerd. Love it!
Thanks for doing this Cam. I think the work you did ahead of the test making the equipment as close to identical as possible made a big difference.
I was expecting the modern bike to be faster so to see this is significant. I think if you compare a rim brake SL6 with a disc brake SL8 the result will be similar.
First of all huge thanks for your effort and time! Really interesting results.
I love this kind of content. Well done! 👏🏼👏🏼
Great content Cam. If only you had the rim brake bike with you on that epic ride with Mitch in France.
You just made my day. Great to see! Thanks.
love these bike test and taking them pretty serious instead of just a afternoon stroll type of test... always pretty interesting.
Hey Cam, I have been VERY tempted make a video and put my Sworks SL6 rim up against a SL8, because I thoroughly believe my SL6 was the fastest bike Specialized made, possibly the fastest climbing bike ever made. Its basically an SL8 but lighter and more aero due to the lack of rotors.
Good on ya old mate, keep it going
My hat off to you for your huge energy and effort, I was very interested to see the result. Very well done.
Yeah would love to see the specialized comparison. Great video!
Fantastically well presented video. Just about as thorough as you can be with 1 person.
Thanks for the vid, im hanging on to my 2010 Dura Ace equipped Merida Scultura now, no need to change if its just as quick as modern bikes. Just a thought, hope you can respond to this Cam. The rider produces by far the most drag, aero frames in comparison give marginal gains. Most modern aero bikes have a lower stack height, and put the rider in a more aero position with a flatter back and so less frontal area. I would ague when other UA-camrs have tested modern aero bikes and compared them to older rim brake models, it is the body position on modern bikes that makes them faster when they test them. You have replicated the body position on both bikes you tested, so it makes it a more level playing field.
Thanks for doing this comparison video. Hope to see another in the future
This vid just cements I bought the right bike back in 2020 when I got tcr adv pro 1 rim and mechanical ❤
Do it! The tarmac sl6 seams to be the most coveted rim bike frame ever made.
I had the opportunity to grab a SL6 Ultralight, but I already own the other most coveted rim brake frame, the Supersix Evo Black. One day I'll grab one
A very nice test. Would love to see more of those with other brands.
Identical geometry would be best obviously. Body position should be identical between each bike. Otherwise making them identical is totally inaccurate because it's ignoring the advantages disc frames have which is the entire point. Wider fork blades isn't just for wider tires but it's more aerodynamic keeping the fork blades away from turbulance off the tire. Something you can't do in a rim brake frame because you need the rim brake calipers to be closer. The disc brake rim profile should also be optimized to be as aero as possible in both rim width and shape since you don't need a brake track or a narrow enough width to work in a rim brake caliper. While tire construction should be identical that doesn't mean the width should be if using the wider clearance available on the disc bike means you can get a faster combination than the tire width you can fit in a rim brake bike.
If you aren't exploiting the advantages that disc has then you're knee caping the entire point of performance gains. Potentially down grading it to the limitations of a rim brake bike. It would be like adding weight to the rim brake bike so you have a "fair" comparison with the slightly heavier disc bike.
Personally, I don't think there's going to be any statistically significant results one way or the other. Body position, good fitting jersey, having a clean drivetrain, good tires and good bearings makes up the overwhelming majority of performance. Everything else is so minor it's extremely difficult to measure outside of a laboratory setting.
Great video Cam, I really enjoyed it.
Perfect balance of humour and nerdy facts
Really enjoyed this and hopefully get to see “another brand”
Keep going with these projects until you get results that help me feel better about all the money I spend on newer bikes😀
The tarmac SL6 rim brake review was the very first video I ever watched from cam.
Rim for the win. I sold my disc brake road bike because it was heavy and would rub. Got a Sworks SL5 rim brake and love it
SRAM or Shimano disk brakes?
I did the same recently. Changed my “modern” disk brakes di2 bike by one S-Works SL6 Di2 Rim brakes. From the change, a new Personal Record in strava every day! In climbs and also in downhills. Why ? I don’t know, both bikes are very similar in groupset, wheels, etc
@@falconbike_onfire What model/brand/groupset was your disk brake bike?
@@kpsig Shimano Dura Ace in both bikes.
@@kpsig it was shimano
You could also look into Canyon Aeroads, they haven't changed as much over the past 4 years, and you can easily find rim brake vs disc brake versions.
No stone left unturned i enjoyed it a bit of an eye opener cam thanks food for thought.
Great video Cam! Rim brake bikes are better on every aspect, people should start thinking with their own head instead of formatting themselves with marketing commercials 😜
Top work, Cam. You should hit up your mates in Sydney, they're always chatting about their TCRs
Great to see a review of the Rim v Disc bikes that makes a good attempt at isolating the difference between both bike types… (unlike others in Australia whose findings pushed disc brake gains using completely different bikes types).
Apart from the performance gain with rim brakes and weight advantage shown in the video, the rim brake bikes are much easier to live on a day to day basis with due to the ease of required maintenance of rim brakes and much lower cost life cycle costs … which makes them a clear winner for me …. Especially on road bikes and given 99% of my rides are in dry conditions
Yep. When riding in a group that small difference isn't going to matter since almost everyone is drafting anyway. And if it is raining, where disc brakes seem to have a slight advantage you aren't going to be riding like an absolute madman anyway.
99% of rides dry? Where do you live? Near 90% of my rides are in rain.
OMG! A 2013 teammachine with dura ace mechanical. My Literal Dream Bike
Best video i've ever watched, woawh.
If i'd have a big company, i would sponsor this guy immediately!
I would like to see the old Cannondale Supersix evo rim vs modern Cannondale. They were quick.
i would assume the modern Evo is quicker on the flat due to its aero shape while the older one is quicker on the hill due to its weight.
And Caad 10
I have two CAAD10 and 3 Supersix Evos, all rim brake. The latest Evo would be faster, just because of aero and big tires. Still love my Cannondales though
@@Shadowboost how much faster than Caad?? Biggers tires arent faster, just more comfort.
@@heinik4349 bigger tires are faster. On the rough roads that are more and more commonplace, they roll faster. Current Evo is 15 Watts faster at 40 kph.
I'm faster on my old Evo than my CAAD10 on any acceleration or climb. That said, there's a 4 pound difference between my bikes, same size and fit
Cam , mate , brother , I just was at my lbs and they have that teamachine same paint , 54 with 105 hardly rode . 2k USA$ here in Seattle and i nearly bought it on sight . I ride a 2014 izalco pro 10spd ultegra , few wheels , sl45s 28mm conti or 26mm pirelli, nothing new but it's great as I'm 55 . I do want more speed and this helped
Keep this up Cam, its very good public interest citizen science.
Great vid! I find myself riding rim brakes more and more as well. I'll probably sell off all my disc bikes next spring and spend it all on gucci steel bikes.
Good video, love your style.
For the conclusion you mentioned that the body position could have been different from the bikes. I think Niel could have helped you to check the position to minimize the difference between both bike positions
Thanks for the great video Cam.
I don’t think your testing with these bikes are done. You’ve evaluated the differences well between frame/brake systems on climbs and flats using mostly controlled wheels and tyres. Now we have a picture of how weight and geo makes a fast bike.
What I would love to see is how the modern bike allows us further advantages (wider tyres and wheels), that the rim brake bike just can’t afford us.
I would love for you to test maybe the same brand of wheels and tyres on the disc bike, except with wider tyres and wheels, as that is the main advantage and trade off with the heavier bike.
Maybe test them both on smooth and rough roads just to see if theres a course specific bias to the bike platforms.
I do think modern bikes with wider tyres are advantageous for most people, as smooth roads are not that common. This is coming from a Rim brake bike rider (2010 and 2018 rim brake bikes).
Its all well and good until you're riding in the wet and raining weather of Northern EU. Sure if you're in Denmark or NL where it's flat (Limburg is an exception).
But we all know that this environment is pretty much the fairest of weather...and doesn't represent everywhere else. Also long term, if you aren't somewhere flat and dry..enjoy replacing your wheels after you wear through the carbon rim.
But it is a good fair test, I admit that, but sometimes the controls aren't really controls because in the real world, controls go out the window.
You’re a funny bugger Cam.
Great clip and content.
I use to own an S-Works SL6 Tarmac, before I got the 2023 SLR01 and so I’ll be keen to see how the next project goes.
Keep putting out these reports Cam. Always interesting 🚴🏼🤙🚵♂️💪
Loved the concept and the resultant video. Yes please try to replicate with other brands.
I would expect the heavier setup to roll further down a hill.
Can’t deny rim is best for road performance 💯❤️
Great vid C💯💯
🎉
No, no rim are worse. You must using more power in hand to braking, and with carbon rims they are many many problem with rim brakes. Disc brakes are ahead of any rim brakes, and are very ease to mainetance.
Don't argue with durian. He's a full blown troll who is in a sketchy relationship with an internet whore, not gonna win that argument mate. @@Pablo_Coach
@@Pablo_Coach You would need a good carbon rim wheel set like the Winspace Hypers to adjust for your describes problems. Go to Reginald Scotts channel and watch his 30min deepdive on why rimbrakes are better. Any Durianrider Video on that will also do. If you think that disc brakes are better to maintain you are just delusional my friend... Sorry to brake (pun intended) to you.
@@franzkohlack8336 BS. Any Carbon rims are delaminated with that high temperatures on descends, and need More power on levers (with disc brakes I use one finger only)
Fascinating. I speculate that the stated measurements of the two bikes might be different than the actual measurements, but you'll need some fancy jig to figure that out.
Fabulous level of critical thinking in how to do a test. Enjoying this much more than the seemingly ad hoc gcn comparisons.!!!!!! Well done!!
I would love to see more of these comparisons of rim vs discs! However, I am sure most bike companies would not as it goes against the narrative most bike brands are pushing today. And yes I am a BIG fan of rim bikes but do own a disc one. Rim for fast days disc for long days.
The bike industry and the people who support it, deserve more of this independant research. I would love to see a pro use a rim brake bike for certain stages in the tour in 2025, purely because theres no argument against it being faster.
I've had a custom steel rim brake frame built using 1'1/8 tubes except for the rear stays. I had been riding a SL6 Domane (2017) Disk bike and although a great all day ride I was always concerned with the tube diameters, the down tube in particular. The down tube here is getting on to be nearly three times the width of the steel tube, so any claimed aero profiling of the Trek tube would have to be nearly 3 times better than a cylindrical shape. It is actually wider than it is long... so that doesn't seem to stack up either. The steel bike rear brake cable pops in and out of the top tube and I went sram axs on the build so I did not have to run any other cables, so it is fairly clean from a cable perspective. Basically a classic looking steel frame with modern parts. It is an absolute weapon compared to the TREK. It is probably an unfair comparison, but I have certainly noticed that most of the tour bikes have much skinnier tube sets/frame than what they were riding say 5 years ago. A think like for like, rim brake frames will probably be more aero and lighter than disc brake. In a dry climate it would be hard to justify Discs, but like me, when it is wet and cold with grimy roads --- I still take the Trek--- with full mudguards!
Love the tests, keep it gong!!
Rim brakes for the win!! Thanks Cam.
Saw this bike at a lbs on Wed and I'm gonna test ride it hopefully today . 2022 disc. Black n white it's calling me ....
Nice touch with the captain planet soundtrack.
Great video, been waiting for this. Durianrider is the GOAT.
It's why iv'e just bought an S-Works Roubaix SL3, it rides amazing.
The BIG difference which you're not even mentioning is the price of course, which makes this choice an even more no-brainer.
Last month I asked a friend of mine, who has ridden for a couple of world tour teams and is still racing in Europe on a pro team, what was his favorite bike and his least favorite bike of all the bikes he has ridden.
Here is what he replied;
"I think my favorite bike so far was the Giant TCR. It was light and handled really well, I could immediately descend better on it. And it’s less expensive than a lot of other high end bikes.
I always thought the BMC road bike drove like a boat. Even after 4 years I never felt great on it. But their TT bike was the best "
BTW, who in the world changes wheels by turning their bike upside down like that??
But it's the TCR Advanced SL he raced on, no?
respect the hustle, my man trying to get an SL8 out of this👏👏
Congrats for the 200k :)
Great content, well done.
Thanks for the confirmation that I don't need to get a new bike any time soon, still love my 2018 rim brake trek emonda. I'll stay away from wallet weight savings a little longer
Same here😊 I will stay with my Emonda for longer 🎉
Excellent video. Ive been asking Norcal to do something similar for months. So can we assume that Jessies claims on the Niel Millar show that a new aero bike is at least 20 watts faster be classed as bollox. I can also recall Chris Horner stating on one of his channels that when he finished Trek wanted him to do a commercial stating that the new Moadone was x watts faster, Chris stated if it was x watts faster he would still be riding the world tour 🤣
Geez you're a funny bastard. I've shared the video with my mates titled it "no I'm still going to ride the ten year old weapon"
Interesting video Cam! Big fan of BMC, disc brake and rim brake bikes. I have a 2008 cervelo which feels fast and very light to this day, but is noticeably less comfortable over time and i'm less confident on descents than my 2020 BMC teamachine with discs. The extra weight does go somewhere for performance but it's hard to demonstrate that with tests out on the road. Something to consider would be a "sketchy" decent test, but it would be hard to show differences aren't related to bike handling. Another thing would be spin down test of the wheels to show the bearing resistance is the same. Qualitative experience about the way each bike feels during each test is also scientifically valid, I'd be interested to hear what you think in terms of bike feel, vibration, stiffness in sprinting and cornering etc. Thanks for the interesting video!
Nice to see more tests on this (long debated) point of contention. I guess the million dollar question for you is ... now that you seem to have shown its faster , are you going to be riding that 2013 rim brake BMC from now on or are you going to stick to 2023 disc brake version and why?
EDIT ... I took a look at few online calculators. Based on those and holding everything else constant (and using some assumed other inputs calibrated to the faster run). I see the following for a 3.6% climb ... 400g of weight for the uphill test is a bit less than a 1s difference ... a 5 second difference over the climb is equivalent to about 14 watts.
the results so far are very interesting....great vid
Cam you legend, 2k Video Quality 🤙🤙
What I was curious to know, is how did each bike feel in each type of test? Speed is one thing and it's very interesting to see those results and I appreciate the effort, time and money you put into these tests. Maybe a video on how each one felt to ride each segment, the pros and cons of each would make for an interesting video. I own disc brake bikes and I love how they stop but I also love how the rim brake bike feels when I ride it, it's more responsive and nimble and just feels more spritely if that makes sense. Of course I don't have the same model in disc to do a back to back comparison though.
On the forums when someone rides a Ritchey Road Logic rim brake and a then a Ritchey Road Logic disc brake, effectively the same bike apart the design changes due to breaking types everyone says the rim brake feels more lively/springy and enjoyable to ride over the disc brake which feels like, to quote one person "like a pig" which could be attributed to the reinforcement to cater for the disc brakes.
I’m very intrigued to see the results of the specialized vs bmc if you were able to make it happen….best of luck on this new endeavor awesome video like always
Great video, Cam. Balanced, transparent and honest. And as a bonus, rim brakes came out on top and we had an interlude from everyone’s favourite vegan.
My favorite vegan is the Austrian artist who made Germany great for a time before the bolsheviks ruined everything.
Interesting test and good work, i know these are time intensive. My conclusion is that the rim is faster for this bike because the frames are both conventional design. All other things being equal, rim is lighter and faster. However, I do believe many modern bikes that emphasize aero are faster. There are frame designs that didn't exist in rim brake era.
People forget that rim brake and carbon rims also featured the first analogue ABS system that activated during wet weather.
🤣 I don't think he has that problem in QLD
Cam, another very interesting series of test outcomes. Real world back to back tests are hard to find.
Perhaps if you carried the extra 235gms in your jersey pockets (hidden from aero influences) on the 2013 bike as a comparison, we'd know more about aero, etc.
Extra mass should make your rolling distance greater, momentum does matter, after all, just as it makes climbing slower, even on slopes below that 'magical' 7-8%. If mass is different, what can the results actually show us?
I've always wondered why pros don't add 2 bottles at the top of each climb before a long descent.
So, my 61cm 2018 RCA @ 7.2kgs with 45mm/28mm OD aero wheels/tyres, aero bars & a slammed -20 stem with Tri-Rig brakes could be faster than a current R5 with discs & Di2?
These tests do of course open up the chance to test climbing bikes vs aero bikes, an R5 vs an S5 perhaps? I love my rim-brake bikes, but I'm not so certain the marketplace does, unless buying a cheap rim-brake 'old-school' bike becomes a thing for many others, too. 🤔
Cam, great effort in getting high quality data! I believe the climbing speed difference is very significant, at 2.5% = 5 seconds/200 seconds.
I strongly suspect the differences you measured are real. But, as much as we might want to draw a conclusion that rim brake bikes are faster while climbing etc., we simply cannot do this.
Even if somehow every other aspect was truly identical, which it isn’t because that’s essentially impossible, there’s always the potential for some unknown error. This of course is the reason that scientific tests, which this is, have to be independently reproduced by others. Just as you brought up at the end of the video.
Just looking at the climbing data, something doesn’t add up. The disc brake bike is 235 g heavier. I’m estimating the total weight is around 110 kg. So, this weight difference is only about 0.2% weight difference. So, weight couldn’t possible explain the 2.5% in climbing speed.
If we then look to aero difference to explain this, I get some back of the envelop estimates that using the rim brake bike would have to be about 8% more aero (8% lower CdA). There’s simply no way the rim brakes are going to be 8% lower total CdA. We know the rider dominates the aero losses. Also, other testing I've seen shows aero differences are very small to non-existent between rim and disc brakes.
So, if there really is something in the range of 8% aero difference, it’s not going to be due to the rim brakes vs disc. It pretty much would have to be rider position.
My point is not to poke holes in your efforts. Getting good data, which you have done, is very hard to do and takes a lot of time and effort. For those who have never done this type of testing, it is much harder than you think to do it well.
I just don’t think the majority of the difference, at least for the climbing test, can be attributed to rim vs disc brakes. I think there’s something else going on.
Cam, thanks again for this effort.
Strongly agree, I tried to estimate the difference needed in weight assuming a constant efficiency, for a 3.6% slope over a distance of 1.47 km at 353 watts, using the formula P=m⋅g⋅v⋅sin(θ)/n. and it would require the bike-rider complex to be 3 kg heavier to explain a 6 seconds time difference. So there must be something else going on here. Would be curious on Cam's hypothesis on this
I am getting tons of these videos recommended to me and I suspect it is a hidden agenda to drive more consumer cycles by making us all think we need a new bike again and have to buy rim brakes now.
The wheels are different. Creative Classic Disc 45 has an internal width of 21mm, the rim brake version is only 19mm wide. The measured width of the tires on the disc bike should be wider, in turn the tire pressure should be lower to get the same rolling resistance and vibration absorption.
The only way to get consistent watts is to use an electric motor.
A power meter is great but for such a test with small differences it might not be the best tool for the job.
Thanks for this testing!! I think it would be fair to say that our old rim brake bikes STILL have a place in our would 😁🤔
I bet Durianrider would lend you his SL8 😉 great idea to compare other makes.. what about Cannondale supersix evo 😊 excellent vid Cam as always dude.. Pete 🚴🏻👍
Good work on the test. Clearly a lot of work went into it. There is a 235gram difference between the 2 bikes, circa (3.4%), but both under UCI 6.8kg weight limit. Would it be fair to bring both bikes up to 6.8kg? Possibly a waste of time, given people's entrenched position on the subject. Your patience with the green shirted rim brake warrior was admirable.😂 I am lucky enough to have both rim and disc brake bikes in my stable. I do prefer the disc brake bike when going down hill, shimano ulterga, having said that the rim brakes (sram red) performed very well this summer when going to a steep hill and I was confronted with a car on the wrong side of the road. Under this test, I can reveal that adrenaline is brown
I don't road bicycle I'm only an amateur mtber but I drive fast cars and what is one of the things you learn when you track race : unsprung weight matters a lot, what is unsprung weight ? pretty much the wheel IF on a rim brake bike or the wheel + brake disc on a disc bike that's what you're seeing here and why I absolutely love my car smaller winter tires mounted on lightweight Oz wheels and hate every spring when I mount the heavy sluggish oem summer wheels even with a whole car between the wheels and me I can feel the difference so on a light bike powered by your muscles for sure it has an impact