Hi Tom,
Originally Posted by
noglider
cplager, we may need to agree to disagree. I feel weight differences in a major way, and they make a big difference in speed for me. It matters whether I'm climbing or riding on the flats.
However, if I'm carrying cargo of significant mass, then the weight of the bike doesn't matter.
I have no problem agreeing to disagree.
Are you riding two different bicycles with the same tires at the same pressure? I'm willing to bet that this has a much bigger difference than the weight of the bike.
In general for flats, physics says it's the total weight of the bike + rider that matters (for accelerating, the weight of the rims/tires counts double, but this is generally a small effect).
One exception to this that has to do with
feel and not speed is that heavier tires/rims have more angular momentum and make the bike feel more stable, less responsive. So if you are doing a slalom course, you might be able to tell the difference with heavy wheels compared to light ones.
Note that almost every bike store I've been to when asked has quoted the same thing that you have: that lighter wheels are important. If you are not racing, then their importance has been greatly over-stated.
Cheers,
Charles