Originally Posted by
olek
Agree with that completely.
But I fail to see how that explains difference in acceleration between bikes with 650b and 27" wheels.
If rotational mass of the wheels is about the same, and their outside diameter is also about the same, they should accelerate in a similar way.
Here is an interesting read on the subject:
http://www.tomsarazac.com/tom/opinions/wheelsize.html
My personal opinion is that once there is wider/heavier tire installed on 650b wheel, it has about same acceleration properties as 27"/700 wheel, and behavior differs only because of wider tire (more plush, compliant ride with a tad higher rolling resistance, and tire would behave much better when taken to moderate off-road situations, like dirt path or gravel road.). But I have to admit that I have sold my 650b bike 2 years ago, and it was not really comparable to my road bikes, so I may be wrong on the subject.
I think you are correct. Personally, I see no difference in acceleration between my 650B bike and any of my 700C/27" bikes. However, my 20" Bike Friday tandem accelerates (and also stops) quite quickly, despite its hefty 50 lb. So even though it's not a direct comparison, I think I can feel the difference with the much smaller wheels. What completely confounds me, though, is that despite the fact that the smaller wheels contirbute much less gyroscopic effect than my road bikes' wheels, I can manage to stay upright on it even when approaching a dead stop. I can literally stay balanced while rolling less than a few inches per second; can't do that on my road bikes. But then, that may be because of a very low center of gravity and not because of a lack of gyroscopic effect.