Crank(area) creak, long story, need help..

Discussion in 'Road Cycling' started by farangbish, Oct 23, 2016.

  1. farangbish

    farangbish New Member

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    I've been dealing with a creak for the past few weeks and I'm at the end of my troubleshooting knowledge. Bike is a 2009 Cervelo S3, cranks are 2012 Sram Red Exogram with GXP bottom bracket. Here's the gist of it so far. It's a creaking/clicking type sound at each crank rotation, more so just cruising along and not really when out of the saddle. It isn't bad when pedaling with one foot, either side. It is definitely coming from the crank area, but even so, I've dealt with alot of noises over the years, so I've gone through all the usual suspects and greased/tightened accordingly( cleats, pedals, derailleurs, cassette, seatpost/saddle, headset, chainring bolts) So originally, I took off the crank, and put alot of grease on it and cleaned the bb bearings and regreased, and they felt smooth. Next ride, everything sounds good for the first 30 min, then the noise comes back. Even though it didn't feel loose and I torqued it, I figured I didn't tighten down enough or overloaded with grease, so took the cranks off, removed some of the excess grease and tightened to the high end of the torque spec, which is pretty high with these cranks(478in/lbs). Same thing, about 30 min into next ride, noise comes back. Next i figured the bb was worn out because they did have about 5000miles on them, and the GXP bb's aren't known for being great. Even though it felt good without the cranks on, I figured maybe when everything is tight, that's when any defects in the bearings will show. So got a new bb, and splurged and bought the Sram ceramic GXP bb this time. Put everything together, and it's whisper quiet on my next ride. This time, it was quiet for about 3 hours of riding... then the same thing.. creaking came back. Maybe not as loud, but still there at each rotation. So that's where I'm at.. any thoughts?? Thanks.
     


  2. CAMPYBOB

    CAMPYBOB Well-Known Member

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    The disclaimer: I am not familiar with GXP BB's at all.

    Remove the chainrings after marking spider and rings for any index positions. Clean and grease up all contact surfaces between the spider and rings. Reassemble and wipe off excess grease.

    Are SRAM bearings press fitted into the cups or are they a just a 'fit' and removable with no tools being necessary? If just a fit or slip fit you can try to bond the bearings into the cup with something like Loctite 641 Bearing Retaining compound. I'll be honest with you here...from my experience even with bearings and cups cleaned with acetone and then allowed to cure for 72 hours after using the Loctite I could easily break the Retaining Compound loose with pedal pressure in just a few hours of use.

    As a guess you may need just a little more axial preload on the bearings. Is there any endplay in your current setup that you can feel or even suspect being present? You don't want to overload those new ceramic bearings, but a lot of the Campy UltraTorque BB ticking and creaking is attributable to too much endplay movement in the crank spindle and bearings inside the external cups. Add another plastic shim to the left side stack?
     
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