SON dynamo slipping

[thesloth]

Seems to be corrosion-related, rather than abrasion. Do you grease the surface?

Could well be. Only greased very occasionally, little enough for it not to count.

[Feanor]

What's the purpose of the cam lever on a thru-axle?
What's it tensioning?

None of my thru-axles have cams.
They either have a hex hole for an allen key, or a simple non-camming lever for hand tightening.

[LittleWheelsandBig]

A QR axle clamps tighter than a wingbolt.

[chrisbainbridge]

I have this on my genesis Day one with a QR.  I have to do the QR up as tight as possible to prevent it happening. 

[LittleWheelsandBig]

Do other folk using through axles have similar semi-circumferential wear marks on the brake side, even if they do not use a SON dynohub?

[thesloth]

A new an unfortunate development on this issue...

I'd been making the effort to ensure that the axle was tightly secured and didn't have any further issues with the dynamo contact moving (although in truth I've mainly been using a non dynamo wheelset over the summer).
I recently swapped the wheel and the cam lever came off:


I have a new axle, but I need to get the old one out. That will involve gripping that protruding stub and unscrewing the axle.
I've tried locking plyers and small vice:



No joy. There isn't enough clamping force and metal on metal just slips. The thread on the stub didn't last long. Have tried putting a bit of sandpaper in between to add some grip.
I have a larger vice (bolted to a workbench). I'll give this a try. This is the only remaining option I can think of.

If that doesn't work then I may ultimately have to resort to the drastic solution of cutting the fork.

Does the hive mind have any suggestions?

[LittleWheelsandBig]

Try some high-quality name-brand locking pliers first, rather than a no-name copy.

What happens if you file flats in the visible large diameter section or use the locking pliers and try to turn that?

If that fails, coring out the threaded stub and using an EZ-out might do it. Alternatively, it might be possible to drill a small hole in the threaded end of the axle and knock in an oversized Torx key, which might give enough leverage to loosen the axle remnants.

[Brucey]

if you just want to get the wheel out without damaging the fork it is usually possible to do this by

a) springing the fork a little (and maybe using wooden wedges to maintain the gap) and then

b) using a saw in the gap (carefully) to cut through the axle

obviously this will leave you with some hub repairs to do, but this is normally confined to the skewer and the hub adaptors.

Good luck!

cheers

[grams]

Is the axle visible at the other end? Maybe you could make a screwdriver slot in it using something like a dremel cutting disc?

[thesloth]

What happens if you file flats in the visible large diameter section or use the locking pliers and try to turn that?

Success!
You sir deserve a beer! Many thanks. (thank you Brucey & grams as well for your suggestions)

I managed to grip and turn the large outer section. Although it spins freely around the axle that seemed to release a bit of tension allowing me to turn the bolt stub with the pliers.

[parkysouthlondon]

Hi Sloth,
I think it's time to get a new through axle. I like the cam type as I like to set the lever vertical when tight. That way knowing if it's coming lose during a ride when you're on the bike. You don't get that with a fixed level.
Alan