What happens if your Wahoo Kickr breaks and you keep riding it?

Kevin Biggs managed to get a cheap Wahoo Kickr that the original owner had listed as damaged and needing repair.

This Kickr had suffered the classic loose woodruff key which led to lots of banging and clunking when the trainer was used. The loose key means that the bearings can move in a way they aren’t meant to, which means they eventually fail.

The following images and words are from Kevin.

The guy ran the trainer for me and it had the usual clonking noise. When I got it home and the cover off it wasn’t obvious what the problem was. I had to hammer the fly-wheel shaft through using a sacrificial bolt screwed in to hit.

Broken Wahoo Kickr - How Bad?
Broken Wahoo Kickr – How Bad?

Once the pulley and bearings were out it was fairly obvious; the drive side bearing had seized and the v-belt pulley had worn into the bearing.

Broken Wahoo Kickr – How Bad?

You can see how the pulley has profiled to the bearing and worn the bearing seal and race, and how the two fit together perfectly!

As the fly-wheel shaft had been spinning on a seized bearing, it had also worn a groove in the steel of the shaft the width of the bearing.

Broken Wahoo Kickr – How Bad?

To complete a ‘temporary’ repair, I shimmed the inside of a new bearing with a thin sheet of copper and put a crush washer on the pulley side of the bearing. I filed the back of the aluminium pulley to remove the burrs and get it flat, also needed to file the key a little shorter so it didn’t protrude beyond the locking surface of the pulley.

Broken Wahoo Kickr – How Bad?
Broken Wahoo Kickr – How Bad?

Reassembled, it runs great, although the crush washer is a little too wide and the pulley just rubs against the cover; so I’m running it with it off at the moment. So I’ve done a few miles on Zwift and it running smooth and quiet, long term repair will be to rebuild the diameter of the shaft with JB Weld and remachine, then install with a shim washer to centre the pulley on the belt line.