Bicycle Mechanics - Ultegra Crank arms on DA BB?

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Gus Riley
06-17-04, 05:41 PM
I'm having some problems getting comfy with my 172.5 DA cranks. After 40 miles my legs are toast, I have hot spots on my feet and my saddle is sore. This is still occurring after over 400 miles (in three weeks, with rest days) of training. I changed from 170 ultegra (Groupo) to 172.5 DA recently, before that I never had the problems I am having now.. I thought there might be an advantage to longer cranks. I think I was wrong. Anyway, I've taken my DA crank arms off and installed my Ultegra crank arms (with DA rings) on the DA BB. Seems to work fine. Anyone know if this is really doable or am I messing up my Ultegra cranks?

Dutchy
06-17-04, 07:41 PM
DA and Ultegra are fully compatiable, so it should not cause any problems.

CHEERS.

Mark
SteveE
06-17-04, 09:50 PM
Did you move the seatpost down 2.5mm when you switched from 170mm to 172.5mm cranks? The increased crankarm length could've caused you to start rocking, leading to your saddle becoming sore. Not sure why your feet would have hot spots, though.

Gus Riley
06-17-04, 09:58 PM
Did you move the seatpost down 2.5mm when you switched from 170mm to 172.5mm cranks? The increased crankarm length could've caused you to start rocking, leading to your saddle becoming sore. Not sure why your feet would have hot spots, though.

Yes. And when I installed the 170s I moved it back up. The hot spots are a real surprise to me too. My Sidis have carbon soles (I use speedplays) so I shouldn't have hotspots, I don't experience them with my 170s.