And the power to screw up.  That sums up how I was feeling when I decided to replace the bearings on my commuting Powertap this weekend.  I had just gotten my training Powertap back from Saris for a similar repair, but that one was covered warranty.  This one was not.

The potholes and rough winter riding conditions had caused one of the bearings to freeze up and I was a weird swaying sensation at times when I used this wheel.  I found some 6901 cartridge bearings on sale (the Powertap hub uses four).  If done right, this whole repair would cost me just $25. I had replaced bearings in other hubs before, so my confidence was pretty high.

Well, taking the hub apart was easy.  I didn’t need to remove any of the electronics and I was able to tap out the old bearings with a screwdriver.  I also pressed the new bearings in with a simple bolt and washers setup. Things were going great and until I installed the  cassette.

The old freehub shell was alloy and fairly worn down, and I ended up cross threading the lock-ring. Crap. Talk about a rookie mistake. Well, the freehub was pretty much gone and I probably needed a new one anyway, so I ordered one from Saris.

Yep, easy to take apart, easy to put back together, and easy to screw up even at the end.

Here are the axle, freehub, and bearings from a Powertap hub.