fixed gear chainring bolts

jtill said:

Is there some trick to getting the chainring bolts on a fixie to stay tight? I have a salsa 39t
chainring with 130 BCD on an old shimano 600 crank, and they keep coming loose. I've tried lightly
greasing the threads, using track-specific chainring bolts, tightening them more, less, etc. They
keep loosening up to the point where the chainring jumps back and forth on the spider when i switch
from powering forward to resisting the wheels to slow down. Help!

This most commonly occurs when the nuts are too long for the combination of chainring and crank you
have, and the bolt comes together with the nut before holding the chainring fast to the crank. You
can: a- Get new fasteners, with the nut side shorter than the ones you've got. b- File/grind the
nuts you have now a little shorter. c- If your chainring's teeth are all "normal" (completely
symmetrical tooth profiles, no special "gated" cuts), you can try reversing the 'ring (side facing
out now faces in) so there's no countersunk recess for the chainring nut to fit within.
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jtill said:

Is there some trick to getting the chainring bolts on a fixie to stay tight? I have a salsa 39t
chainring with 130 BCD on an old shimano 600 crank, and they keep coming loose. I've tried lightly
greasing the threads, using track-specific chainring bolts, tightening them more, less, etc. They
keep loosening up to the point where the chainring jumps back and forth on the spider when i
switch from powering forward to resisting the wheels to slow down. Help!

Some chainrings are just thinner than others. Probably your bolt is bottoming out before securing
the ring. Either pass the nut side of the fastener lightly across a grindwheel or get a set of the
thin shims Shimano uses under their cheap thin chainrings. That spacer goes between ring and arm.

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Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971