I accidentally over tightened the front thru-axle on my Cannondale Synapse 1 and the hex cover (I think – not sure on terminology) has snapped off. The other side (last pic) seems striped so unable to do anything from there.
Does anyone know how I can remove and replace the thru-axle now?
The bike and maintenance is new(ish) to me so any guidance would be really appreciated!
by gayspaceali3n
5 Comments
I think you should stop torturing your bike and take it to your LBS
>The other side (last pic) seems striped so unable to do anything from there.
If you can get a pair of vice grips on the stripped side, that might work. Otherwise the next step would be to hammer a torx bit into the end you stripped with whatever you have tried so far. You’re working with a carbon fork, so you do not want to brace the fork leg against anything otherwise you can very easily crack the fork.
Be aware that you want to turn CLOCKWISE to loosen the through axle if you are turning from the stripped end. Righty- tighty does not apply.
Hard to see in the 4th photo but are the threads sticking out on the far side of the fork (opposite the bit that snapped off)? That would lead me to guess that the threads were bottomed out on that side and wonder if something was missing from the hub (spacer or wrong wheel hub width?)
Regardless. There are several ways to approach this depending on what tools and experience you have.
1: Sheepishly bring it to your bike shop and let them handle it.
2: Use a screw extractor on the end you broke off
3: If you have a set of torx wrenches you don’t mind sacrificing, pick the next size up from what will fit in that rounded out hole oppisite the side that broke off. Support the axle on something solid (I’d probably put the broken off bit back in the hole and sit it on a block of wood, an extra pair of hands would be helpful here, then hammer the torx into the hole. The reason you’re supporting the axle is so the hammer force goes straight through the axle into the wood and doesn’t damage the fork). Once the torx is fully seated, then turn it clockwise to loosen the thru axle.
4: Drill through the axle from the side that didn’t snap off, with a bit slightly large than the rounded out hole there.
5: Sheepishly bring it to your local bike shop and let them replace the fork and axle.
Remember that the opposite side to the broken head means it will be ‘righty loosey’ – maybe if you’ve not been doing that get some angle in the Allen key, get a flat edge lined up, and try again
You could use some penetrating oil to loosen the threads. You could notch a slot into the protruding bit of axle and then use a big flathead screwdriver or a thin lever like a pedal spanner to break it loose.
In my opinion if you’ve snapped off a thru axle head “accidentally” you’re probably lacking skills or experience, so just take it to the LBS
“Max. 11Nm”