Originally Posted by
jupiter422
"percentage of the total torque that 'x' exerts on the crank is now 100 times smaller"
Yes, but it's still 'x'. It doesn't really matter what the % of total torque is. What matters is the difference in work required. The work required to rotate the crank one revolution on the stand is no different than the work required to rotate the crank one revolution on the road. Integrate that over a long ride and see how much extra work you have to do. To some people, that is worth the expense. To pro riders in a big stage race, that is certainly worth the expense, even if it is only in the kJ range.
First off, this is seal drag I am talking about; has nothing to do with bearings. I have an old, worn out cartridge bearing (from a formula hub; destroyed by setting my chain tension too high on my fixed gear) sitting on my desk at work with rough, pitted bearings (but no seal) that will easily cause something as massive as a crankset to spin forever on the work stand. Pay a bit more for better sealed steel ball bearings, and you'll get the same benefits. Ceramic bearings come with good seals because the market is the type of people who will pay the premium for all this stuff, and part of the marketing appeal of ceramic bearings is that they roll forever on the work stand. On the other hand, the bearings that come standard in bottom brackets are basically the same bearings you can get out of the McMaster Carr catalogue, which are sealed up tighter because they are designed to roll at thousands of rpms under torque, not at 100 rpm with zero torque applied.
Second, if 'x' is 0.1% of the torque on the crank, it matters not a bit. It is probably less of an effect than the increase in fluid drag from the grease in the bearings that you encounter when it's cold out vs. riding in 90 degree weather. Pros ride them because they have these products thrown at them by sponsers, though maybe the younger ones are spurred on by the placebeo effect benefits. Hey, if you think you should climb faster because of your equipment, you have a vested interest in proving your thinking right, and if this psycological factor makes you faster, then so much the better.
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Cat 2 Track, Cat 3 Road.
"If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --
the tiniest sprinter