diamacleod

I recently made a chainring swap. Without thinking about it much, I slathered the securing nuts and bolts comprehensively with grease, to prevent them from seizing. During the installation some grease got on the chainring and/or spider faces where the two come in contact. The result was a chorus of light clicks during each pedal revolution, and no reasonable torquing of the bolts could stop it. The fix was to thoroughly degrease the mating faces of chainring and spider, and keep everything dry during the reinstall, (except for a little anti-seize carefully applied to just the chainring bolt threads).

Presumably these clicks were generated not by flexing or intermittent contact, but by very slight slipping of the chainring relative to the spider when static friction was broken as the chain yanked on the chainring during the pedal rotation. (Fixed wheel riders use this movement, at low chainring bolt torque, to center the chainring precisely). For anyone else besides me who needs reminding, the lesson is: confine any grease to the threads and make sure grease doesn’t get onto the chainring and spider mounting faces when the bolts are greased and inserted. (At least don’t lubricate those faces intentionally, as I have seen some forum gurus recommend. )

Other opinions? Is it worth greasing just the bolt flange, so all torque can be directed to the bolt threads? That surely wouldn't help much. Or the outside of the nut, in case it creates clicks by jerking about during deformation of the crankset? But are clicks ever created that way?

FBinNY 

Another reminder of the importance of friction in our everyday lives. I also use only a very light (mostly solvent) oil on the chainring bolt threads on road bikes, since the rings are usually left on for life. In the real world, I'd rather drill out a chainring bolt if needed a few years down the road, than deal with bolts that might work loose.


On the track it's just the opposite, using well greased threads since these get changed routinely.

linus

Loctite. No grease.

dsbrantjr

Another demonstration of the fallacy that "if some is good, a lot is better". Sometimes, like the Brylcreem slogan says, "a little dab'll do you".

Andrew R Stewart 

Funny I've lubed chainring bolts for over 3 decades with very good results. Shuts up clicks, let's the bolts be made real tight (and still take apart) and keeps things from rusting. BTW the torque of the rings should be transfered to the spider arms through the nut side of the bolt, not the threads. Andy.

Reynolds 

I've always greased chainring bolts and never had any problem. Maybe my torque is too weak for that.

FastJake

I always grease the threads. It allows you to get the bolts tighter and allows you to remove them in the future. I've never had one come loose.

FBinNY 

Greasing or oiling the bolts isn't the issue. It does help for taking them apart in the future, and allows greater torque without holding the nut when assembling.

However, you want maximum friction between the chainring and the faces of the arms. If you depend only on the bolts to hold it together the chainring will work the bolts loose as the rotating crank changes the direction of stress. There isn't enough precision in the fit of the bolts in the arm or chainring to eliminate this movement, so chainring to arm friction is absolutely critical.

billnuke1 

There can be two torque values when reading plans for a machinery build. One value with grease, light oil, loctite, etc...and a value dry. Two different numbers. I doubt if it make that much difference on our bikes. Just don't over torque

dprayvd

Jens to Udo: shut up, Bölts.