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Praxis Works chainring bolt torque spec

Posted: Thu Feb 16, 2017 8:42 pm
by SpecializedColnago
Does anybody have a torque spec for Praxis Works aluminum chainring bolts. Ive searched on this forum and did a general google searches and can not seem to locate anything more than a generic torque range for aluminum chainring bolts. Ive tried Praxis Works' webpage as well with no luck. Thanks for the help.

Re: Praxis Works chainring bolt torque spec

Posted: Thu Feb 16, 2017 8:54 pm
by youngs_modulus
Is there a reason you think that the generic torque spec wouldn't work for the Praxis Works bolts?

Re: Praxis Works chainring bolt torque spec

Posted: Thu Feb 16, 2017 9:10 pm
by SpecializedColnago
Well the generic torque range for aluminum chainring bolts is 44-88 inch pounds so definitely a large disparage in torque there.

Re: Praxis Works chainring bolt torque spec

Posted: Thu Feb 16, 2017 9:56 pm
by youngs_modulus
Again, is there a reason you think that range won't work for your bolts? That's not an especially large range in absolute terms.

Believe it or not, people were able to assemble bicycles even before torque wrenches were common in bike mechanics' tool boxes. I don't mean to be snarky, but an exact torque specification may be less useful than a little common sense.

44-88 in-lbf works out to 5-10 NM. That's not a huge range: from as tight as a typical stem clamp bolt to twice as tight as a stem clamp bolt. Since chainring bolt threads (M8x0.75mm) are nearly twice the diameter of common stem clamp bolt threads (M5x0.8mm) you can be confident that 88 in-lbf is not excessively tight.

If you're uncomfortable with ambiguity and want a single number, try 7.5 NM (66 in-lbf). It'll be fine.

Alternatively, tighten your chainring bolts 'til they strip and then back 'em off a quarter-turn.

Re: Praxis Works chainring bolt torque spec

Posted: Sat Feb 18, 2017 6:13 am
by sp3000
SpecializedColnago wrote:Well the generic torque range for aluminum chainring bolts is 44-88 inch pounds so definitely a large disparage in torque there.


I have had a very bad experience using a torque wrench when tightening aluminium chainring bolts... mine were dura-ace 7800 bolts and before I even got close to the correct torque they bolts started to deform.. after having to drill them out and buy new bolts I learned my lesson.. from that day i never use a torque wrench on chainring bolts, they are too short and too soft so I find the best is by hand until they feel right (which is very easy to feel).