Rounded off the brake disc bolts

Message

spiderwheels · #1 Post by **spiderwheels** » Fri Jun 06, 2014 4:24 pm

The allen bolts holding the left side front disc were so tight I managed to bend the bit on my impact screwdriver and round off the inside of one of the bolts.

I'm not sure what to do with it now as I don't want to take it to a local bike shop and have some monkey ruin my wheel trying to drill them out. Are there any localish experts on here who could remove the bolts in return for beer / cider / shot / cafe latte tokens?

fatboy · #2 Post by **fatboy** » Fri Jun 06, 2014 6:57 pm

Possibly sacrifice a hex bit or hex key and have that welded into the offending fastener, hopefully the heat generated by the weld will expand the threads enough to free them from the grip of corrosion,
Use low strength locking compound along the entire thread length of the new bolts, this will help prevent the bi-metallic electrolyc reaction
Or fucking seized to you and me !
Good luck

Falco Frank · #3 Post by **Falco Frank** » Fri Jun 06, 2014 7:21 pm

Ive had this happen in the past too and this worked for me...

Soak with releasing fluid / shock n unlock overnight or as much as possible.

Using the next size up Star drive bit (yes, this might get sacrificed too), hammer it into the hex slot and then use your impact driver on it.

Sometimes, actually trying to tighten up the bolt initially can help but I think thats after trying the above.

Good luck

spiderwheels · #4 Post by **spiderwheels** » Fri Jun 06, 2014 8:37 pm

Thanks for the tips. Worth trying before I take it to the shop..

#5 Post by **mangocrazy** » Fri Jun 06, 2014 9:15 pm

If all else fails, you could always drill it out yourself. Start with a drill bit the same size (or fractionally larger) than the rounded off hole and drill another 5mm or so into the fastener. Make sure to use a new, sharp drill bit. Once you've drilled down to below the level of the fastener head, just increase the size of the drill bit in steps, drilling down to the same depth as the original drilling.

At some point the fastener head will separate company from the shank and you can remove the disc and then remove the remainder of the fastener with a pair of pliers or mole grips.

KitchenSync · #6 Post by **KitchenSync** » Sat Jun 07, 2014 10:25 am

File a ouch to a sharp point - drive it into the bolt square on to get a purchase and then angle it and chase it round with lots of light taps.

MartDude · #7 Post by **MartDude** » Sat Jun 07, 2014 11:47 am

If you have to resort to drilling, use a left-handed drill bit. This can sometimes help to loosen the offending bolt enough for it to be unscrewed, without resorting to an extractor

spiderwheels · #8 Post by **spiderwheels** » Mon Jun 09, 2014 9:07 pm

KitchenSync wrote:File a ouch to a sharp point - drive it into the bolt square on to get a purchase and then angle it and chase it round with lots of light taps.

What is an ouch?

Does anyone know where I can get a set of disc bolts quickly? I have 5 of the 6 out.. the last being the one that rounded off but I'm sure it will be out soon. I ought to replace the lot so looking for a new set..

KitchenSync · #9 Post by **KitchenSync** » Mon Jun 09, 2014 9:39 pm

It's a mispelt punch. I removed terminally ill header nuts using a punch the other day. I'm sure it would work for anything as long as you can drive it round at the right angle.

spiderwheels · #10 Post by **spiderwheels** » Tue Jun 10, 2014 5:30 pm

KitchenSync wrote:It's a mispelt punch. I removed terminally ill header nuts using a punch the other day. I'm sure it would work for anything as long as you can drive it round at the right angle.

I don't hand a punch so in the end I beat the largest slotted end of the impact driver into the head of the bolt. By that time it had been soaked in shock & unlock for 3 days and whacked with a hammer about 400 times so the impact driver got it turning fairly easily.

fatboy · #11 Post by **fatboy** » Tue Jun 10, 2014 7:31 pm

Result !
You getting the beers in then ?

KitchenSync · #12 Post by **KitchenSync** » Wed Jun 11, 2014 12:03 pm

fatboy wrote:Result !
You getting the beers in then ?

Are the beers to settle those nerves that click in at 120mph when your mind starts wondering about a cast aluminium wheel that's been whacked with a hammer 400 times?

spiderwheels · #13 Post by **spiderwheels** » Wed Jun 11, 2014 1:09 pm

KitchenSync wrote:
fatboy wrote:Result !
You getting the beers in then ?
Are the beers to settle those nerves that click in at 120mph when your mind starts wondering about a cast aluminium wheel that's been whacked with a hammer 400 times?

Shhh..