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Cottered Cranks

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Cottered Cranks

Old 03-18-17, 07:30 AM
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Join Date: Oct 2014
Location: Milwaukee
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Bikes: Trek Domane SL7 83 Cannondale, 70s Raleigh International, 70s Bob Jackson, 70s Gitane tandem, 2018 Trek Domane SL7, Giant Yukon MTB

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Be sure to measure cotter diameter

Originally Posted by ramzilla View Post
Go online & buy a couple sets of new cotter bolts & nuts. Have on hand before starting work. In the meantime, start basting the crank set with penetrating oil or diesel fuel. Unscrew the cotter nut till it's 1/2 way off & tap it with a hammer. If it doesn't come loose no worries. Remove the nut, get a punch, & pound the living crap out of the cotter bolt till it pops out. (Why not - you're not going to re-use it. You got new ones). No big deal. Have fun. Be good.
There are a few different diameter cotter sizes. If you buy new ones be sure to get correct size. Not a bad idea to reuse old ones if you can. Best to put back on side they came out of as the tapered surface was often filed to get the crank arms exactly in line or the cotter to slide deeply enough into the hole.
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