My girlfriends bike is running a Shimano centrelock hub with Avid brakes. The problem is that there is play developing between the rotor and the hub. The first time I noticed this was before we were about to start a 1500m decent on a 4 day tour. We took into a local bike shop who said this was a regular problem with these hubs and that if we tightened the lockring it would damage the hub. He said the only solution was a new hub!

Eventually I managed to persuade him to tighten the rotor, but this morning I discovered the play again.

If I lock on the brakes the disc stays locked but the wheel and hub can roll a little forwards and backwards with a nice creaking sound as it does it.

Anyone else experienced this problem? Am I running into problems if I tighten the lockring to more then 40Nm which it says on it?

I,m not 100% sure which adapter she is using to run the avid discs, but I presume its a DT Swiss.
Cheers.