Bike Cassette Play and Cassette Wobble - fix, prevention and bike maintenance

I was cycling with my friend when suddenly he stopped. My back wheel is jammed and won't turn. We'll demonstrate on my bike on the stand. First, we checked the brakes pads to make sure they weren't rubbing. The rear derailleur hanger appears straight and the wheel inserted correctly. What I did notice was that the whole cassette wobbled and I could move it from side to side. I shifted his bike as though shifting to the smallest chainring although the chain didn't move (this would make it easier to replace the wheel. When I took off the wheel, the lockring had completely come off and the cassette was loose. I asked him how old the cassette was and he said since he got the bike about 6 or 7 years ago. I also asked him when was the last time he torqued the rear cassette onto the freewheel. "Never."

I made sure all the cassette cogs and spacers where properly on the freehub and tightened the locking by hand. Then with the straight edge of my multi tool, I push the groves in the lockring as hard as I could (you could use a small rock to pound it tighter but I didn't want to damage the lockring). I replaced the wheel and we both road the next 15 miles home. A quick easy repair and fix.

This emphasizes the need to make sure the cassette is properly torqued each time you do yearly bike maintenance or replace your cassette. The method we suggest is quick and easy as shown in the upper right corner.

A loose cassette can cause wear and damage to the freehub spline and in this case could leave you out on the road without a way home. The trick to getting the cassette back on and tight is not hard. But had this problem happened when going fast or downhill, it could have brought the cyclist to a holt and been disastrous. So, keep that cassette torqued and pay attention to a good maintenance schedule to prevent other problems.

Just a note: Cassette play and wobble can also occur when installing a new cassette such as a 9 or 10 speed cassette on an 11 speed freehub if you forget to place the proper spacer on first to adapt the spacing for the 9 or 10 speed. Wobble can also seem to be occurring if the wheel is out of true or the wheel has not been properly inserted into the bike frame dropouts.