I was wondering if anybody with the Bosch Performance Line has any trouble with the large aluminum nut that hold the small chain ring on? I put the chain ring put grease on the threads and torqued the nut to 20 to 25 NM and the threads failed. I know the threads are left handed that was not the problem.
large nut on Bosch that holds chain ring on
- Thread starter Timbo
- Start date
Was the torque specified dry or with lubrication? 20 to 25 Nm dry is different than with lubrication. If spec'd dry you probably added quite a bit of torque with the grease. Especially aluminum, I am always conservative with aluminum fasteners. Reduce aluminum fastener torque by 10-15% when referring to steel fastener torque.
No grease, wipe threads, install by hand, tighten while holding opposite side crank, I use a 1/2" ratchet, only because the socket is 1/2" drive, light torque, and that's all there is to it. No reason to get crazy on the torque here. Being aluminum, it's very easy to damage the notches as well as the threads by getting over zealous.
Similar threads
