I have a Trek Powerfly 5 (2018 model). Recently the rear Rockshox axle has been working completely loose. If I tighten it up as recommended , ie, wind it up until it's tight, back it off half a turn and then push the lever over, then after a few miles on our forest tracks it works loose. If I over tighten it, then the rear wheel binds.

 

Has anyone had the same experience, and if so, how was it fixed?

i dumped my qr levers long ago and use these now.

 

https://mtzoom.com/collections/thru-axles-and-skewers

I'm thinking along the same lines. The front axle lever had worked itself so loose that it wouldn't engage when I flipped the lever over. This has now been adjusted and is now working ok at the moment, but for how long....

i would just get rid of them esp if you ride hard off road as my rear one has a spring inside it and when that goes it dont take much for it to come loose and could damage the frame where the axle threads in to.

 

plus it just looks better

Ooooh! Nice!

you can get these if you want color options but there 3x the price.

 

http://www.carbon-ti.com/products/axles-and-quick-releases/x-lock-12-mm-rear

QR wheel clamps can't come loose on their own. It sounds to me like it's what's on the axle that's coming loose, like whatever holds the bearings in.

Could this have been caused by previous overtightening of the QR clamp, and consequent wear on the bearings? A few weeks ago I noticed that the bearings had become quite loose. I've adjusted them and all is well again at the moment, but I'm wondering if I need to change the bearings

As long as the wheel spins freely and sounds OK, the bearings are probably OK.

 

It's difficult to comment without knowing what you have on your axle, but it sounds to me like you didn’t tighten the locknut properly that locks the bearing adjuster nut.

QR wheel clamps can't come loose on their own. It sounds to me like it's what's on the axle that's coming loose, like whatever holds the bearings in.

With bearings in mind , my thoughts were how is the wheel binding up from tightening the axle ,

This indicates that theres an issue with the hub somewhere as you shouldn't have that much influence over bearing adjustment / binding by tightening up an axle .

Could this have been caused by previous overtightening of the QR clamp, and consequent wear on the bearings?

There should be a centre section between the bearing that acts basically as a preload

if you have winched the axle up and squashed this slightly you may have effected the bearing adjustment

What hubs are you running or do you know if its running sealed bearings or separate balls ?