Bicycle Mechanics - Crank Question
Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.
02-22-05, 07:44 PM
I'm replacing the crank on my old Trek. Will any double with a square taper fit on the BB?
02-22-05, 07:49 PM
Theoretically, you need to make sure that the new crankset sits exactly like the old one to work correctly. If this was my bike, I would replace both the crankset (including rings if they haven't been replaced in a long time) and the BB. That way you get a perfect match. In addition, the chain and cassette are probably worn too. Why are you replacing the cranks???
02-22-05, 07:53 PM
Well it's a fixie and I'm putting some 165mm cranks on there to replace the 170's.
Well it's a fixie and I'm putting some 165mm cranks on there to replace the 170's.Well, that does not matter. Taper on the spindle has to match the crank and different cranks have different spindle length requirements. Physically, it can be crammed on, assuming the ring doesn't end up hitting the chainstay,but the chailnime could be badly whacked.
02-22-05, 10:07 PM
Maybe..same amount of rings? Yes I think..do a measure and try it.
The chainline on geared bikes can be altered some...more than a ss or fixed gear bike.
the tensioner will let the chain angle ok.
02-23-05, 04:29 AM
the answer is yes.
it may really throw your chainline out of whack. or it may not at all. if it does only a little, you can move your bb with some spacers. or you cans space your chainring out a bit. or you can space your fixed cog out a bit. or a shorter/longer spindle BB if needed. instances like this, where chainline may be off by only a tiny bit, are where adjustable chainline BBs come in handy.
what is the old crank? try and find as similar to that as you can, even if you only have "eyeball" measurement to go on.
Powered by vBulletin® Version 4.1.12 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.