Originally Posted by
bigfred
I don't know that I would agree with the assertion that the recent trend has been toward longer cranks.
I would contend that the current trend is toward an increasing emphasis on "proportional" cranks and/or use specific cranks.
I think we're increasingly seeing a cycling population who are no longer willing to accept a one size(or very narrow range) should fit all solution from the manufacturers.
At least from my perspective, we increasingly are seeing the crank length of stock bikes vary with frame size. All be that within the traditionally narrow range.
But, we're seeing fitters paying increasing attention to both leg lengths and hips angles and recommending cranks above and below the standard range as appropriate. And, manufacturers are increasingly offering lengths beyond the traditionally narrow range (167.5-175).
All of which I feel is a move in the correct direction.
It's altogether possible we are both right. One current trend is to ride smaller frames, i.e. to depart from the French Fit. So if a bigger guy is riding a smaller frame, and he wants his usual longer crank, then that is how we see longer cranks on smaller frames. In my 30+ year experience, crank length has always been matched to frame size, it is just that in the past the match of cranks to frames was smaller cranks than now by about one size, i.e. 2.5 mm. I can see how that could be due to larger people riding those smaller frames these days. Since it is the same size me riding the same size frame as always, there is no reason for my crank length to increase when I outfit a new bike.