Campy chainring bolts on post 2015 cranks

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biwa
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by biwa

Just to confirm, on 2015+ chorus/record cranksets, is it anti-clockwise to loosen the chainring bolts (from the behind of the crank arm, facing the bolts)?

How much are they tightened to in the factory? 8-10nm? I have a record crankset under 200 miles with no sign of corrosion, and the bolts simply do not budge with a proper a T30 wrench. Any special tool/technique I'm missing? Thanks.

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Calnago
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by Calnago

This is why, even on brand new cranks, I will disassemble, add a little low strength threadlocker (loctite 222, purple), then reassemble with even torque all the way round, little bit at a time on each bolt to about 6.5-7.0Nm. I know the specified torque is 8Nm, but with the threadlocker you don’t need that much. You’ll appreciate this kind of attention to the initial build when it’s time to disassemble things.
But yes, it’s normal thread direction... righty tighty left loosey. Make sure you have a good torx bit and it’s firmly anchored.
I remember the torque spec for chainring bolts on a SRAM SRM crank was 10Nm. Ridiculously tight and when I loosened them off there’d be a “crack” as they broke free, a spark, and little poof of smoke that was smellable.
Last edited by Calnago on Fri Jul 19, 2019 8:30 pm, edited 1 time in total.
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Attermann
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by Attermann

Campagnolo has already put tread locker on the factory bolts, no need to disassemble

biwa
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by biwa

Calnago wrote:
Fri Jul 19, 2019 7:45 pm
I remember the torque spec for chainring bolts on a SRAM SRM crank was 10Nm. Ridiculously tight and when I loosened them off there’d be a “crack” as they broke free, a spark, and little poof of smoke that was smellable.
Lol, such drama for loosening a bolt! Thanks for the confirmation.

biwa
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Joined: Fri Sep 21, 2018 8:39 pm

by biwa

Attermann wrote:
Fri Jul 19, 2019 7:55 pm
Campagnolo has already put tread locker on the factory bolts, no need to disassemble
I wonder if it's to do with the factory threadlocker that is causing my problem..

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Calnago
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by Calnago

I do this because I’ve found that factory assembly is sometimes not very even all the way round. It’s just something I like to verify myself for peace of mind. Especially after having not done this on a new crank before only to have a chain ring bolt come loose on the first ride of a major descent and take a big gouge out of the chainstay of a brand new custom frame. Plus, 8Nm with threadlocker can be a kind of a pain to remove, as you’re finding out. Deep breath... take a hard left turn and you should achieve success.
Last edited by Calnago on Fri Jul 19, 2019 8:29 pm, edited 1 time in total.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
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Calnago
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by Calnago

biwa wrote:
Calnago wrote:
Fri Jul 19, 2019 7:45 pm
I remember the torque spec for chainring bolts on a SRAM SRM crank was 10Nm. Ridiculously tight and when I loosened them off there’d be a “crack” as they broke free, a spark, and little poof of smoke that was smellable.
Lol, such drama for loosening a bolt! Thanks for the confirmation.
Yes it was, and because it was on such an expensive crank, kinda freaked me out a bit for sure.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

by Weenie


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