The Science and Perception of Bikes

Questions about bike hire abroad and everything light bike related. No off-topic chat please

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BeeSeeBee
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by BeeSeeBee

This has been mentioned in a few other threads, but I think it's interesting enough to warrant it's own thread.

News Article: http://www.slowtwitch.com/Tech/Thoughts ... _4571.html
Further Forum Discussion: http://forum.slowtwitch.com/gforum.cgi?post=5231787

Our brains are such curious things, we find patterns where there are none, simply fill in the blanks with made up information when we can't see the complete picture, basically we're incredibly susceptible to all sorts of mental trickery, yet at the same time are so absolutely certain that we're not.

How do we square the above (which admittedly just touches on the subject) with what we hear parroted over and over on these forums about ride quality/stiffness/acceleration/etc.? Are we all going to claim that somehow WE as a group are so much better than pros/everyone else and can absolutely differentiate minute differences (millimeters of saddle height, frame layup differences, 50g of weight, etc.). Is it simply an attempt to certify our cycling credibility to others by making claims to appear as experts?

I really can't notice any differences between bikes if certain things like positioning and tire pressures are controlled, and that's something that has been pretty freeing to me. I don't worry about needing 15% more torsional stiffness, or a beefier bottom bracket, and that's allowed me to stop worrying about the bike from a performance aspect and treat it more as an outlet to meet my subjective and emotional desires like aesthetics and "heritage."

I do imagine my next bike will probably be an aero frame, as that's an aspect that has been measured, correlated, and found to be beneficial; a lot of the other remarkable claims about bike performance... not so much.

mjduct
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by mjduct

I realize that at a certain point it's all mental, but I had a 2006ish Specialized Allez (aluminum low end model) that was so noodly the bottom bracket would sway 1.5-2" back and forth when I hammered on it in the trainer. You can't pretend that doesn't have real consequences on the road. When I upgraded to a 2011 Cervelo R5, the BB had zero perceptible budge in the trainer. Now does a bike with +/-10% stiffness than my Cervelo have any perceivable difference under my butt? Nope for sure not.

Same thing when riding 1200 gram carbon tubulars with 23mm vittoria corsas compared to 2000 gram clincher training wheels with 28mm gatorskins. (otherwise set up similarly bikes). There is a substantial difference in my exertion and how long I can hang with different riders/ my speed/exertion cresting known hills in my area that I am very familiar with. You know when you are working hard what the bike is doing.

I fully believe that there is alot of marketing out there, but there are large differences that can be felt/ gained when truly "upgrading" a bike or a significant component like wheels. Trading in your 2012 zipp 404 firecrests for the 2015 version might not get you any real gains besides the placebo. But upgrading the fulcrum racing 13's or whatever pig of an alunimum stock wheelset most bikes come with to some lighter, stiffer, more aero carbon wheels will definitely contribute to speed on the bike.

my $.02 given to you and a discount!

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uraqt
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by uraqt

Bikes are easy, it's all measurable ...

Stereo equipment is a whole different ball game : )

I think the question and it's been asked here a lot, is were is the line, what make the bike better? Do we need 10% stiffer cranks or 1% faster brakes? Cable shifting vs battery powered? I think a lot of this gets in the way of most people. Is a better bike going to improve the time I spend on the bike? It's really all about me doing something that make me happy, not keeping up with the Jones.

Now if buying things makes you happy that is cool too, but this is a "bike forum not a buying forum : )

20 year old steel bike VS brand new carbon bike yes they are different, hard to say what one is "better" I bounce back and forth between bikes and there are strengths and weakness to both. I know that just as in cars, planes, boats the real limiting factor is Me.

C

Permon
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by Permon

Weird article.
Saying that only aero is measurable and stiffness/inertia/weight is placebo is just making me laught.
Who is the author? I cant bealive this guy ever ride a bike.

What I can feel is the stiffness and comfort, what I really dont feel is more aero bike.
I am not able to feel if I ride at 33km/h or 33,7km/h because of aero frame. No way a person can feel the difference.

I am not sure who the pros and the other testers were in the studies, but I can feel differences in franesets and I feel differences between wheels.
For example....my Bora35 are the same weight as my Hyperons....but I feel the differences in handling.
The low profile rim is not affected by wind so much and it makes the handling more precise and easier in downhills.
I also feel the Hyperons are more comfortable.

And differences in stiffness and comfort of the framesets? Given the same wheels and tire presure - of course that there are differences between all the carbon frames out there.
Significant differences....which is great.
Everybody prefers something else...I need super stiff front end to feel good on the bike....and it took me some time to find one like that.

Just my 2cents.
Last edited by Permon on Sat Sep 06, 2014 11:04 am, edited 1 time in total.

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de zwarten
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by de zwarten

BeeSeeBee wrote:millimeters of saddle height, frame layup differences, 50g of weight, etc...
I really can't notice any differences between bikes if certain things like positioning and tire pressures are controlled, and that's something that has been pretty freeing to me.
I do imagine my next bike will probably be an aero frame, as that's an aspect that has been measured, correlated, and found to be beneficial; a lot of the other remarkable claims about bike performance... not so much.

to quote the article: "Let the rationalizing begin! "
Not all claims can be measured, but some of those are thereby not by definition worthless. They are just more personal.

I agree you cannot feel 50g of weight or frame layup. However, I (personally) felt that my saddle was 1cm lower over the course of a 70km training ride. It just felt harder to pedal, and I immediately thought about my seat post not being tightened. I guess not everybody will feel this, but I am doing a lot of distance and have always exactly the same saddle height on all my bikes.

About comfort: I have said it over and over on this forum:
tires DO make a difference, wheels a bit, and frames not so much.

I can race Paris-Roubaix on my stiffest alu frame with open pavé 28mm tubulars at 5 bars and it will be very comfortable.
I could do the same on an old steel bike with 8 bars pressure in the tires and it will be hell. In anyway, carbon wheels in PR are still nonsense whatever Zipp wants us to believe:
they themselves prove from the article that even though the 303 is more vertically compliant, it doesn't matter compared to tire pressure which is the key variable determining comfort.
And to conclude: many carbon wheels break, while most nemesis survive for years.

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kbbpll
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by kbbpll

The article made me curious - how do you blind-test wheels? Cover them from rim to hub? And what _exactly_ were the tests and results on wheels? One specific example with actual data would be nice. The article seems to imply that testers cannot feel wheel differences, or that the differences they feel are wrong, and I have a hard time believing it.

uraqt
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by uraqt

This is funny, I totally believe it... Homo sapiens are redundant we just don't realize it yet.

C

Franklin
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by Franklin

Oh boy... that article sure hits a sore point. There's a lot of truth though.

1. Blindtesting framematerials always leads to the conclusion inperceptible. Denial in here is huge, but as far as I know every time it's being tested it's a huge dud. So even in the off chance WW members have very sensitive genes it's certainly minor.
2. The "heavy wheel" mantra is quite simply a myth. The math has been done, a kilo at the wheel does not matter twice as much. Also, our acceleration (even if we are called Mark Cavendish) is relatively puny.
3. Seat heighth/position is elusive. Efficency tests show that humans are actually very adaptable. A few MM here and there do not matter at all. => This is actually quite logically considering cycling is a dynamic sport. Nobody in the world exists who is perfectly stable on a bike. In reality we move fore and aft all the time. And don't bother with a new and old chamois... we all know the answer. The old one is substantially thinner, thus lowering our position. Of course, a too high seatpost will always be noticed... but a lower seatpost is undetectable for most of us.*
4. OTOH Aero and overall weight are pretty much a constant factor. And contrary to what people think they count at all speeds. Aero/lower weight is basically a free gain (if not free monetarily)

Finally: Not being noticable for most humans does not mean it's not there! I don't notice the weight differences between my bikes, but they simply matter.That will also be true for stiffness etc.



* reason three is why the love for fitters is so sad. They are all quacks. There is NO solid science behind it. This is why every fitter just guestimates an dwhy the results vary so much. It's money through the drain. Just go with Genzling and adjust after a few rides and you will end up with a good position.

Franklin
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by Franklin

de zwarten wrote:I could do the same on an old steel bike with 8 bars pressure in the tires and it will be hell. In anyway, carbon wheels in PR are still nonsense whatever Zipp wants us to believe: .

Uhm no... You gloss over aerodynamics. Sorry de Zwarten, your position is very true for non-competition, but a pro is always better off with an aerodynamic wheel, even at Paris Roubaix.

This is because I don't think wheel breakage is a major factor in P/R. *Shrug* the most epic one was with Alu wheels (Kuiper).

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BeeSeeBee
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by BeeSeeBee

Franklin, I pretty much agree with everything you said, especially the bit about not noticing doesn't mean it's not there. I posted this study done years go in conjunction with Cervelo. Damon Rinard mentioned in the thread that they have since gone on to do more, but have kept it mostly internal, and I can't blame them, the "it doesn't really matter" isn't going to sell a lot of bikes. Clearly there are measurable differences in the frame materials (the geometries are very similar), but he also said that even those were too small to be noticed by most people.

Permon wrote:Weird article.
Saying that only aero is measurable and stiffness/inertia/weight is placebo is just making me laught.
Who is the author? I cant bealive this guy ever ride a bike.


Josh Poertner, former lead engineer of Zipp, now owner of Silca and Damon Rinard, Cervelo Engineer (In the SlowtwitchThread), so I'm inclined to give them some benefit of the doubt, given their history of incredibly insightful comments and tenure working on the cutting edge of technology in the sport.

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Tinea Pedis
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by Tinea Pedis

I just wish I had the facilities to be able to take the bet of the chap in the other thread (where this study was posted) who said he could pick the difference (blinded) between the Venge and the Tarmac. Easy money.

Funnily I have a steel and Ti frame. Same groupsets, saddles, fit and wheels (swapped between the two bikes). I certainly can appreciate and know the difference in ride feel between the two. But weight, honestly, not a chance. And there's half a kilogram between the steel frame weight and the Ti.

martinko
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by martinko

Franklin wrote:...
but a lower seatpost is undetectable for most of us.*
...
* reason three is why the love for fitters is so sad. They are all quacks. There is NO solid science behind it. This is why every fitter just guestimates an dwhy the results vary so much. It's money through the drain. Just go with Genzling and adjust after a few rides and you will end up with a good position.


Not really for my knees, they will let me know. I remember riding my very first longer ride with old mountain bike. I did have the saddle too low. It was ok for short rides, but after that ride, I was not able to ride bike for about a month (repeating pain in right knee for each stroke). After raising the saddle higher I found out by myself why the correct saddle position is so important.

Similar thing happened to me last year when I changed my bike and wrongly positioned cleats on shoes. There was no problem for several rides (probably 500 km in total). But suddenly, in the middle of 90km training ride my left knee started hurting. Few weeks later, it was gone. Surely, after that I checked the saddle few times and corrected cleats' position.

Or I am not that adaptable... :D

Franklin
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by Franklin

martinko wrote:
Franklin wrote:...
but a lower seatpost is undetectable for most of us.*
...
* reason three is why the love for fitters is so sad. They are all quacks. There is NO solid science behind it. This is why every fitter just guestimates an dwhy the results vary so much. It's money through the drain. Just go with Genzling and adjust after a few rides and you will end up with a good position.


Not really for my knees, they will let me know. I remember riding my very first longer ride with old mountain bike. I did have the saddle too low. It was ok for short rides, but after that ride, I was not able to ride bike for about a month (repeating pain in right knee for each stroke). After raising the saddle higher I found out by myself why the correct saddle position is so important.

Similar thing happened to me last year when I changed my bike and wrongly positioned cleats on shoes. There was no problem for several rides (probably 500 km in total). But suddenly, in the middle of 90km training ride my left knee started hurting. Few weeks later, it was gone. Surely, after that I checked the saddle few times and corrected cleats' position.

Or I am not that adaptable... :D


With a too low saddle I was talking a bout a cm or so. Most people simply don't notice. In fact lab tests show no reliable loss of efficiency. If we are talking more than that even an oaf like me will start to notice.

On your MTB, I'll be very carefull as I'm not a physician nor was I withness of what happened... but if the saddle was just 1 cm too low (which ofc I don't know!) considerng the dynamics of cycling I seriously doubt that would cause such problems in isolation.

On Cleats: cleat placement is indeed much more tricky as that causes direct strain/friction. Yet that said: There's no scientific method to adjust cleat angles, so everyone in the world just uses a position that feels best. This is why a 5% leeway each way is so nice to have^^.

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de zwarten
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by de zwarten

Franklin wrote:
de zwarten wrote:I could do the same on an old steel bike with 8 bars pressure in the tires and it will be hell. In anyway, carbon wheels in PR are still nonsense whatever Zipp wants us to believe: .

Uhm no... You gloss over aerodynamics. Sorry de Zwarten, your position is very true for non-competition, but a pro is always better off with an aerodynamic wheel, even at Paris Roubaix.

This is because I don't think wheel breakage is a major factor in P/R. *Shrug* the most epic one was with Alu wheels (Kuiper).


I said carbon where you think I said aero.
Carbon wheels break. Last example was Vanmarcke vs. Cancellara. Vanmarcke lost that sprint because he had a cracked front rim. So he couldn't hit this front brake. He tried to hit the rear brake but that wheel was changed (this one allegedly because of a flat) so when it mattered the most on the velodrome, he lost the race because of carbon wheels. https://www.youtube.com/watch?feature=p ... f4wg#t=239

I will rephrase: a good carbon wheel can help winning Paris-Roubaix. But for everybody out there who is not sponsored (you and me), they make no sense at all. So those comfort claims that Zipp makes about their wheels outperforming other wheels in Roubaix is ridiculous. The can claim those wheels are more aero, but nothing more. They can as well claim those wheels are more prone to failure which means loosing the race altogether.

About seat positioning: everyone here with 10.000 km/year (like me) will feel a 1cm change in the saddle height. If not, it's because you ride different bikes at different heights. Human bodies can get used to that. But once the body accommodates, it will feel changes even if they are small. That's what I feel and what other people around me feel. It can have something to do with being flexible or not etc., but it's definitely something real.

nathanong87
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by nathanong87

that's why u build the illest looking bike a disregard all other metrics. money green

by Weenie


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