Bicycle Mechanics - Removing Chain ring bolts

Can you remove chainring bolts without using the special tools? Just the lad who ive got a bike off has used too big chainring bolts, so the chain ring is loose.......but i cant seem to un-do them.......any tips please?

Cheers

Normally it's an allen key on the outer, and you can usually use a screwdriver or similar flat blade to stop the inner half turning.

yeah, i thought doing that, but couldnt seem to stop it spinning with the screw-driver.....i'll have to try again i suppose though, cheers.

:) Try using some spray lube on it, Then just let it set over night.

Generally chainring bolts are simply 5mm allen heads like many other bike fasteners. Simple enough. However, like may bolts there is a backside. In the case of chainring bolts this consists of something that looks like a large slot head screw. However, the male side of the chainring bolt often precludes use of a large screwdriver. If the chainring bolts are too long so that you can't use a large screwdriver you may need a chainring bolt wrench which has a tab that sticks down inside the male part. Otherwise, if they aren't too tight you may be able to use a screwdriver on one side, just enough to hold the female part still as you turn the 5mm side.

tried screw-driver......but i couldnt stop it from spining round........ive been 2 my local bike shop, but he didnt have any 4 sale OR actually have 1 himself!! :(

So i guess i can try sum lube!

If the lub does not work you can grab the head of the slotted part with a vise-grips. You may need to get new bolt after but it does work. If worst comes to worst you can always drill 'em out.

Originally posted by RainmanP
Generally chainring bolts are simply 5mm allen heads like many other bike fasteners. Simple enough. However, like may bolts there is a backside. In the case of chainring bolts this consists of something that looks like a large slot head screw. However, the male side of the chainring bolt often precludes use of a large screwdriver. If the chainring bolts are too long so that you can't use a large screwdriver you may need a chainring bolt wrench which has a tab that sticks down inside the male part. Otherwise, if they aren't too tight you may be able to use a screwdriver on one side, just enough to hold the female part still as you turn the 5mm side.


Long, and to the point...

Take a wide (large) sloted screwdriver and grind out the middle so it bridges over the male end of the allen bolt. If you do it right you'll have a really cool tool.:) :D :D

I find that a US dime held tight by vice grips does a good job.....

OK, I just went and took another look at my chainring bolts. It appears that the male part of the bolt can bottom out on a lip, preventing the male from protruding, which I thought might be part of the problem. So you should have access to the whole width of the "slot". If you haven't already, you should pull the crank off so you can get better access. It is still a little awkward to deal with so you may want to clamp your allen wrench in a vise if you have one so you can place the bolt on the wrench then have one hand for the crank and one for the screwdriver or both for the screwdriver. You will need a very large screwdriver that spans both sides or try a coin in a pair of vise grips as D*Alex suggested. Even a washer. Anything you can get sufficient grip on that engages both sides of the slot.

I have some cranks that came with washers to take up that little bit of slack in the bolts. When you replace the bolts be sure to grease the threads.

The "Voice of Experience" says that if your hand slips off the allen key, it is possible to slice your knuckle on a very sharp metal tooth. I know the workings of the knuckle joint are a wonder to behold, but I really prefer mine to stay in their original wrapper.