Fitting recessed nut front brake - thoughts on drilling an 8mm hole?

Hi all,

Just wondering if anyone has had any bad experiences with regards to drilling an 8mm hole in the back of an old steel fork to accommodate a recessed nut?

Is it better just to buy a new brake caliper that has a longer thread and stick to traditional methods of fitting?

Hypothetically speaking, if I chose to drill, is it better to use a front caliper or a rear caliper and then a longer nut? Just trying to gather some ideas around which would best maintain the structural rigidity of the fork.

Any help would be appreciated and I hope these don't seem like stupid questions.

Cheers,

Jon

Hi Jon

I just pushed the recessed bolt up into the fork and not through the back. I did some research and found this article by Sheldon Brown ( see front, option 3 ), which gave me confidence in the approach
http://sheldonbrown.com/calipers.html

This way no drilling is needed. The steel fork is really strong, I checked it the other day after riding like that for a couple of weeks and it all seems fine

Andrew

As with the little note under that suggestion on Sheldon's site, I wouldn't recommend it.

Drilling is a piece of piss.

I would drill it and did with my steel forks, no problems.

I have done it with a few old forks and its super easy! It looks better on the finish too. Try putting some masking tape over the hole when drilling to minimise any paint damage

Thanks all for the suggestions

I've gone with slotting the recessed nut inside the fork which seems to be holding up at the moment - partly because I haven't got a decent drill to hand so a quick fix will do for the time being.

Although if any loosening arises I'll be making that 8mm hole for sure.

Thanks again,

Jon

I drilled my daily commuter bike, no problems

I've gone with slotting the recessed nut inside the fork which seems to be holding up at the moment - partly because I haven't got a decent drill to hand so a quick fix will do for the time being.

As noted above, this is specifically questioned on Sheldon's page regarding this

That's Sheldon's suggestion -- I can't figure how this option would secure the brake adequately against the tendency of braking to rotate the shoes forward.-- John Allen

Drilling out a fork is genuinely very simple, I did mine with a handheld drill. Make sure you buy a good quality 8mm HSS drill bit and set your drill to turn relatively slowly. If it spins too fast it will heat up the fork, instead it should cut the metal out a bit like a rotating chisel. It's also good to add some sort of cutting fluid, I used fairy liquid but chain oil would do the trick. This will help to lubricate it and keep it cool, but you may want to stop every now and then to let it cool as well.

If you don't have brakes yet, buy 2 front calipers so you can use a regular length allen bolt on the (newly drilled) fork and a standard nyloc nut on the back. I've got a double-front pair of silver tektros if you need some. PM me for details.

As noted above, this is specifically questioned on Sheldon's page regarding this

And for good reason. Properly mounted, across the front and rear faces of the fork, the bending motion caused when the front brake is applied is spread across the whole of the width of the fork. If it's mounted to the front alone, the only thing holding the brake in place is the front of the fork, and the only thing stopping the brake from rotating rearwards is the thickness of a rather thin bit of steel. The possibility of the nut loosening isn't really the issue - the problem is the possibility of the front face of the fork bending, and taking the front brake with it.

Understood... I find myself in this situation after already having one damaged fork (although the damage was not because of braking stress) so the last thing I want is this new fork to pack in.

Will make a hole when I get my hands on a drill.. At the moment I only have a 3 mile commute and tend to backpedal for 95% of the time that I need to slow down so it's not getting a hiding..

Thanks again for all your help!