Rear Wheel Bearings - Installation Tip

[MattR]

This applies to the 2007/2008 bikes, but perhaps 2005+ (if anyone can confirm). Hopefully, this gives everyone a heads-up in order to prevent you from experiencing similar issues.

Background Info:
After installing new bearings, my rear wheel felt like it was binding when the nut was torqued to 60 ft-lbs. The aluminum stepped-washer between the 2 bearings on the sprocket side was replaced with the new bearings. Everything appeared to be lined up ok since the axle slid through easily during mounting.

Root Cause:
I really hated to push out my new bearings, but I needed to find the root cause. After reheating the hub, I tapped out my bearings and removed all spacers, etc..

First, I double-checked to make sure all bearings were correct. On the 2007/2008 bikes, the sprocket side has a large outer bearing (6005) and smaller inner bearing (6004). The brake side has the same smaller bearing (6004). Everything was good according to part numbers.

Next, I made an interesting observation on the aluminum stepped washer. If you hold it up to the light, you can slightly see one side stick out farther than the other. At first I thought it was just imagining something. Well, I held the washer in between the 6005 and 6004 bearings (like installed on the bike). The washer definitely has a slight asymmetric/offset to it. In the correct orientation, the washer OD has a slight clearance to both bearings (perhaps more clearance with the larger 6005 bearing). If you flip the washer over, then the washer OD contacts the larger 6005 bearing on both its OD and ID. This in effect causes the washer to drag on the bearing's OD (not good!). I could also see score/witness marks on the washer OD where it was scraping against the bearing OD.

Since I had my older parts handy, I compared those bearings and washer setup. I noticed the exact same thing (i.e., the asymmetric washer clearances). I could tell by the witness marks from the previous installation which bearing was contacting each washer side. For the record, my previous installation was correct and the washer had proper clearance with the larger 6005 bearing and wheel rotated freely.

Conclusion:
I believe the washer orientation is the root cause why I felt the binding in my rear wheel. I have reassembled my wheel with the washer in it's correct orientation (i.e., to ensure clearance with the larger bearing OD) and it now rotates properly when nut is torqued to 60 ft-lb.

Here is the incorrect installation:



Here is the correct installation:


Here is the stepped washer. Note: I marked the outboard side (with "O") to remind me during installation.