


Hi fellow bike enthusiast. I was cleaning my bike recently and after removing the rear wheel I’ve noticed some scoring marks on the thru axle. They aren’t very deep but I can feel them under my nail. Is this a sign of worn hub bearings and something to worry about? Or is it just normal wear? It’s a rear thru axle on my hardtail mtb so it gets some abuse.
Attaching pictures of the axle.
by Ignaply
3 Comments
It’s probably the derailleur hanger causing this. Check to see if it’s loose.
Make sure that the axle is torque’d up to spec, I have seen this happening on bikes that come around and the bolt is barely hand tight. It would also be wise to check for the stays triangle alignments as a small deviation gets magnified with the lateral forces that a bike experiences (more so in MTBs than road bikes). I would also check the state of the bearings, specially on the drive side where they get more load, as a worn cartridge will have slightly more play and could bind.
Its also a wise move to give the axle a light coat of grease when installed.
That is not the actual axle, it is just called thru axle, as in it goes through the wheel hub to secure the wheel and preload the bearings, the bearings sit on the actual axle.
You will be fine