Wheels great up grade... Why not up grade the bearings instead?
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....and bearing drag is totally insignificant. Even if you have the worst bearings out there, there is little room for improvement in terms of speed/performance. You could probably help longevity by getting better bearings but that's it.
My bearings were totally shot in my rear hub when I replaced them (it took me a while to figure out that was the source of a noise) and I definitely didn't get faster or notice any improvement other than eliminiating the noise when the new ones went it.
Exactly. What you want to reduce is your rotational mass (see: Rotational Mass). Lower friction / lighter bearings will allow your wheels to spin slightly smoother, but you'll still be rotating a heavy mass about them. To gain the greatest efficiency, a lighter wheel set is what you need. That's why when people put heavy rims on a car, it becomes harder for the car to accelerate and also harder for the car to stop, because rotational mass is working against the direction the car is trying to go. Don't spend the money on ceramic bearings...look for a good deal on nicer set of rims. I too have Bontrager Selects because I just started road biking and wanted to do so on a budget; I'll be upgrading wheels later this year.
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Unless you're a competitive racer, rotational mass makes no difference, but, of course, total mass does, when your climbing.
I guess it depends on what you're going for; since lighter wheels spin easier than heavy wheels, one should be able to ride the bike with less effort, making for a more enjoyable, more sustainable ride.
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On the flats weight is virtually meaningless. It increases rolling resistance in the smallest way by causing the tires to flex a tiny bit more. 450 grams (1 lb.) decreases speed by about 0.02 mph (0.03 km/hr) - that's three seconds per hour at 20 mph (32 km/hr).
When climbing that weight decreases speed by about 0.1 mph (0.16 km/hr) on a 6% grade at 250 watts.
Rotational weight is different from any other weight only when speed changes: it takes more energy to spin up heavier rims/tubes/tires and they don't slow down as fast when you quit pedaling. You get essentially all of that extra energy back when you coast (if you're not applying the brakes). And the extra energy is quite small in proportion to the total.
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because they're useless on bicycles.
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Ceramics have great applications in high speed bearings. Bearings on bikes don't spin that fast. I have ceramics in the freehub on one of my wheels. I needed two 6803 bearings and the distributor sent the ceramics instead of what I ordered. Didn't notice until it was all apart so I put them in. Suprisingly enough, I didn't get faster or smoother.
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Bearings on your bike dont spin that fast. On the internet my bike will combust if I dont have them. In real life, not so much. But on the internet.........
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Blown way out of proportion
The statement about upgrading wheels is typically this: Wheels are the biggest upgrade you can do on a bike.
What it should say: Upgrading your wheels is the most cost-effective way to reduce weight on your bike.
You can get a 1500g set for about $300ish. So, if you have a 2000g wheelset, that's a 500g savings. Trying to save 500g just about anywhere else will cost considerably more.
A well-built 1800g wheelset is better than a poorly built 1500g wheelset. Now, it might be all in my head, but a smoother bearing does feel like it's easier to bomb down descents for me. I would never buy ceramic bearings though, I'd rather save the money and get some ABEC5 steel ones.
The statement about upgrading wheels is typically this: Wheels are the biggest upgrade you can do on a bike.
What it should say: Upgrading your wheels is the most cost-effective way to reduce weight on your bike.
You can get a 1500g set for about $300ish. So, if you have a 2000g wheelset, that's a 500g savings. Trying to save 500g just about anywhere else will cost considerably more.
A well-built 1800g wheelset is better than a poorly built 1500g wheelset. Now, it might be all in my head, but a smoother bearing does feel like it's easier to bomb down descents for me. I would never buy ceramic bearings though, I'd rather save the money and get some ABEC5 steel ones.
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