They get a considerable loading on then as they have to pass on the leverage. Think I've tried and failed on a small roadbike in the past. Maybe tried on my old DT or KDX in the past. Have some left over material but can't remember. Too long ago and a bash on the head since.
But simple to try and measure wear/ovalisation. Measure free play wheel off ground. There will always be a little. Write it down and check after a ride. Ride quality will be affected if you bind it up too tight and under load won't ever be as smooth as rolling bearings.
Once bearings are toast however they will be worse and often people don't notice that.
