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Dangers of one less chainring bolt

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Dangers of one less chainring bolt

Old 09-14-13, 11:20 AM
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jdefran
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Dangers of one less chainring bolt

This bolt was located on the inner part of the crankarm for the small ring of a triple. Is it dangerous to ride with just four bolts holding the inner ring? I figure there isn't a whole lot of torque in that gear so I would think it's fine. I really don't want to mess it taking it out. Do you have an experience to share?

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Old 09-14-13, 11:43 AM
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Not really dangerous, but not a good thing either. I wouldn't worry, but would plan of completing the set th the first opportunity.

The effect and importance depends on which bolt and how you ride.

The stress on the chainring is greatest when cranks are horizontal, where the chain is loading the top of the chairning, so the least important bolt is the one that lies inline with the cranks. How you ride is also a factor, since there's very little load on the rings when spinning on flat ground. But if you like to sprint up short steep hills, or have long grinding climbs, this missing bolt can be your proverbial missing horseshoe nail.
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Old 09-14-13, 11:44 AM
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Originally Posted by jdefran View Post
This bolt was located on the inner part of the crankarm for the small ring of a triple. Is it dangerous to ride with just four bolts holding the inner ring? I figure there isn't a whole lot of torque in that gear so I would think it's fine. . .
Torque input is the same in each gear. Chain tension is the crank's output and is highest in the smallest ring. I would not use a small ring with a broken bolt.
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Old 09-14-13, 11:49 AM
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Instead of troubleshoot first I ran you smart folk..I removed the crank and found the bolt was long enough to simply unthread and replace. Thanks for to responses though
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Old 09-14-13, 12:15 PM
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Wilfred Laurier
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i have on a couple of occasions
ridden with one missing chainring bolt
on the small ring

on each of these occasions
the small ring has folded over
or broken in half
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