Current Projects chat and miscellany

Surely the 'leverage' issue is just the gear ratio, which crank length contributes a bit to, but much less than chainring and cog size. So for the same chainring and cog size, longer cranks will be a slightly higher gear than shorter cranks. If you adjust for this with chainring and cog size, then crank length becomes irrelevant to 'leverage' - and (assuming tester is right about it not making any difference to human power output) the only thing it will make any difference to is comfortable cadence.

Yes, but bear in mind that your self-selected preferred cadence will probably change if you change crank length, it turns out that people tend to have a preferred (and limiting) foot speed, not repetition rate. You can test the limit fairly easily by doing low gear spin outs on the rollers - you'll probably find that if you max out at 170rpm on 175mm cranks, you can jump straight onto 170mm cranks and hit 175rpm, i.e. you're not limited by ω itself but by the product ωr

Exactly

Thanks guys, think I'm slowly getting it.

So, a smaller crank will still have the same foot speed, but a higher RPM as each rotation has less physical distance for the foot to travel than a longer crank?

But a longer crank with the same gearing will have the same power output, but a bit more leverage for hills and the like and a slightly slower speed?

So, basically, if you got two riders on a track with the same level of power output, one with longer cranks and slightly higher gearing, and another with shorter cranks and slightly lower gearing, basically having the same gain ratio, they would be doing the same speed?

oh no, there are no LBS anymore the last shut down last year, there are 2 evans!

He was puffing out his chest and giving it, "yes well they just cant hold the stock like us...." (while trying on oversize sunglasses and not being able to sell me some velcro straps because the only have large amounts of stock that small manufactures cannot supply....)
*unt

What a twat.
I loved those old school bike shops when I was a kid, emporiums of the interesting and fun, and still do today.
And although I do get a lot of components from Wiggle and CRC, as they are cheaper because of their huge stock, I still pop into my LBS for advice from the old boy behind the counter (although the mechanic ain't up to much) from time to time.