a couple of weeks back realised that my chain slipping was due to loose cones on XT hub giving 4or5mm or so of play on axle
took apart replaced bearings/packed with grease and tightened so just spin nicely and same when QR done up
20miles later loose again - not as much but still means will need to adjust and to be honest wouldn't expect to take cone spanners on a ride
normal operator error or some other problem?

