3 ms·
Can you explain the physics of rotating mass savings being more important? The top of the wheel moves twice as fast as the bike, but the bottom of the wheel doe
by Nutmog 11y ago
Can you explain the physics of rotating mass savings being more important? The top of the wheel moves twice as fast as the bike, but the bottom of the wheel doesn't move at all so don't they balance out? The frame isn't static - you still have to accelerate it frame along with the wheels when you're speeding up.
If your route has a lot of uphill, then I'd expect that 1.5:1 ratio to get closer to 1:1 where the work you do is more fighting gravity than inertia.
- adrianN 11y agoIt takes energy to make things rotate: https://en.wikipedia.org/wiki/Rotational_energy https://en.wikipedia.org/wiki/Rotational_energy The wheels have a rather large diameter and go pretty quickly. Both diameter and angular velocity are quadratic terms. You could now do the math to see how much energy it takes to accelerate a bike to a given speed. But you're right, going uphill or at steady speed completely changes the picture.
- bch 11y agoHere are some articles[0][1] -- and to be clear, the tone of the first (bicycle) article is appropriately "fussy". One person who gets groceries on their bike may not notice, but a competitive racer might notice. So whether it matters (enough) depends on the situation. With suspended bikes, wheels are also never part of the "sprung" weight; minimizing unsprung weight in suspension is always beneficial. I don't have metrics for how many grams deliver $x performance, though. [0] http://velonews.competitor.com/2012/06/bikes-and-tech/technical-faq/technical-faq-does-wheel-weight-matter_223209 http://velonews.competitor.com/2012/06/bikes-and-tech/techni... [1] http://www.tuneruniversity.com/blog/2011/04/part-i-why-wheel-weight-slows-most-people-down/ http://www.tuneruniversity.com/blog/2011/04/part-i-why-wheel...