Rear axle nut thread stripping / Shimano Nexus Hub


New Member
May 4, 2011
I've got one of these

For a year it was fine, but earlier this year I had to have the rear cog and crank cog set changed due to wear and tear. The original 22 teeth rear cog was replaced with something larger and the crank cog with something slightly smaller.

Since that change, I've suffered from constant stripping of the nut thread on the rear axle on both sides. Sometimes the nuts go after 30 miles, sometimes after 150 miles. I know it's not down to me overtightening the nuts as I've had techs at various bike shops replace the nuts. The result is that rear wheel moves forwards and the chain looses tension.

I don't know if this is a result of the hub not being reinstalled properly after the cog change or some weird extra torque because of the new cog set, or the wrong nuts being used (although both 3/8inch and 10mm nuts seem to have been tried at various times.) or some other reason - but I'm pretty sure it's not simply overtightening.

Any ideas on how to diagnose the problem and then fix it would be hugely welcome.

Try adding a couple of STAR WASHERS (i.e., one on the outside of each dropout) ...