# Chainring bolt failure



## ki5ka (Dec 17, 2006)

Nothing like a complete failure to simplify diagnosing the problem :/ Finally figured out why we have been having problems when we're in the small ring.


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## Hurricane Jeff (Jan 1, 2006)

Probably don't want to use aluminum chainring bolts, especially on the small ring on your tandem....Im assuming they are aluminum, right?


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## ki5ka (Dec 17, 2006)

Naw, we just ripped through steel cause we're like that ... I'm lying, you're right, they're aluminum  

... and I replaced them with aluminum because thats what I had laying around. Glad you posted 'cause I probably would have just left them, now you've motivated me to find some steel ones. Did some damage to the crank where the ring seats so I'm going to have to deal with that. Mangled pretty good. Did my best to flatten it out but it looks like choosing a new crank is in my future...


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## ki5ka (Dec 17, 2006)

Funny, found my own post; forgot all about this. 

We got nearly another year out of that old TruVativ crank. Lost the small ring again, this time to stripped threads. Guess it's time to bite the bullet.


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## TandemBear (Aug 18, 2013)

ki5ka said:


> Naw, we just ripped through steel cause we're like that ... I'm lying, you're right, they're aluminum
> 
> ... and I replaced them with aluminum because thats what I had laying around. Glad you posted 'cause I probably would have just left them, now you've motivated me to find some steel ones. Did some damage to the crank where the ring seats so I'm going to have to deal with that. Mangled pretty good. Did my best to flatten it out but it looks like choosing a new crank is in my future...


Concur. I wouldn't use Al ring bolts on the small ring of my single and DEFINITELY not the tandem. I know a lot of people who've had nothing but problems with alloy bolts - and that's on single bikes. Wouldn't even think about it on a tandem, given the much higher torque loads (two riders PLUS greater rear wheel traction and no front wheel lifting on steep climbs). Switch 'em out ASAP! And as far as damage to the crank goes, if you can file the damage, get the surface square/flat and add a charinring spacer or two to achieve a flat, true chainring, you should be all set. Unless the damage is more extensive than that, I'm guessing you'll be good to go. Good luck.


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## Okayfine (Sep 7, 2010)

Looking at the rings, OP needs to change them out anyway.


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## ki5ka (Dec 17, 2006)

Okayfine said:


> Looking at the rings, OP needs to change them out anyway.


Replaced in January...


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## Okayfine (Sep 7, 2010)

Small ring looks fairly sharked out already. Might be the perspective.


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## ki5ka (Dec 17, 2006)

Either that or we are REALLY kickass riders that tear the sheit out of our gear in a couple of months of riding... actually... I like that explanation and I'm sticking with it till someone suggests otherwise!


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## Okayfine (Sep 7, 2010)

I switched the granny ring to steel to prolong the maintenance interval there. I don't remember how quickly we were shagging an aluminum granny (?!), but it was an issue. Plus, with many steel rings, you can flip 'em and get 2x the life.


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