Any wisdom about how I can fix this?
Many months ago, I under-tightened the rear axle nuts on my commuter bike and the wheel came off while riding. It’s happened two more times since then despite my best effort to tighten. It looks like the gripping washer has actually damaged the hanger on this aluminum frame, which you can see as lines in the silver area in the photo (nut removed, green-rimmed washer pulled out from it’s normally flush position). It looks about the same on the other side of the bike.
Scott Bikes says, yep, it’s damaged and the grooves probably explain why the wheel has come off repeatedly. They say I should replace the axle and spacer hardware and just tighten it really well.
Oooh, that does look bad. I’d ask on http://bicycles.stackexchange.com
Philip Durbin Good idea
not sure what replacing the axle will do if the threads are not stripped… Was the dropout always that shallow?
Roger Sacilotto – yep, always that shallow. The green spacer has a notch that sticks out into the gap of the dropout
I might reface the dropout and get new washers, It doesn’t seem that it should be more involved than that, especially if the axle threads are good enough to get to the appropriate torque