MTB rear wheel thru axle coming loose

[SwissVan]

In essence. I think you are undertorque-ing it. I suspect I have been all this time before I checked the reccomended numbers.

 

What kind of torque are tightening to now?

 

I tightened it tight without a torque wrench, I'm a mechanic by trade so have a feel for what is tight and too tight.... 

[SwissVan]

Yeah I think I just got an axle with bad tolerances... At least it's a point you are aware of now and can be a part of your pre-ride check 

 

Pre ride check? = lick my glasses clean and dry them with a tissue

But ja, will definitely monitor it for awhile and see if it starts loosening again

[SwissVan]

Google searching this topic, there is a known problem with disk brakes sometimes causing the skewers to come loose. Been around for a while and there have been lawsuits. More a problem with the front fork than the rear.

 

No skewer, just a thru bolt that can only be loosened with an allen key

Checked the front wheel, its the same type of system and still tight

[SwissVan]

If the wheel axle binds onto the through axle for any reason it will tend to loosen the skewer axle.

 

How do you see this?

Had a close look tonight and it does not seem to be able to

 

The unit in my scalpel doesn't come loose.

the unit in my giant did.

Check the rear wheel drop out isn't lose. this will cause the thru axle to shift around a bit that causes it to losen up

 

With the wheel out and moving it by hand It has about 1-2mm movement in fwd / rear direction, is this normal?

 

but otherwise it is tight, no side play or anything

 

You can probably also just safety wire it.

 

That would be a last case scenario and quite difficult as there is no protruding part bolt head large enough for a hole to thread the wire.

 

I'll first give it back to the Spaz shop to fix, if it continues to loosen

[SwissVan]

Thanks for the comments chaps 

[MDJ]

I've got a 12mm thru axle disc road bike (Giant Defy) that seems to have the same problem - also seems to only happy on the rear wheel.

 

It's happened about four times now over a 3 year period - I noticed that the wheel seemed a bit lose after this weekend's riding, checked and the axle was lose. Luckily I'm riding with an IDT axle that is quite long, so very low risk of completely coming off.

 

I thought I was losing it, so thanks for this post. Definitely something to keep an eye out for!

[solty]

Get a slightly longer thru axle, put a nut on the other end and you're golden.

 

More seriously, also happened to a friend on the first ride after a service. Shop probably didn't tighten it enough.

[SwissVan]

Get a slightly longer thru axle, put a nut on the other end and you're golden.

 

More seriously, also happened to a friend on the first ride after a service. Shop probably didn't tighten it enough.

 

Agree with the second point, most probable

[sirmoun10goat]

Bolts, nuts, pins, loctite...trying to fix a problem that should not exist.

 

Take it back to the bike shop and make it their problem

[MudLark]

That would be a last case scenario and quite difficult as there is no protruding part bolt head large enough for a hole to thread the wire.

 

If the problem persists, change the through axle to the type with an adjustable handle and then use some form of reusable to tie it to the frame so it can't rotate. It's better than a crash.

[Headshot]

I have a cheap Roval hub on my Enduro. It has a large ugly lever on the axle. I have noticed that the axle can loosen slightly and the benefit of having the lever is I can easily check the tightness before or on a ride. I think it's just something that needs to be checked every ride.