Concave head bolts on new bike make drilling for safety wire nearly impossible!

Has anyone else attempted to drill the heads of their front caliper bolts for safety wire? The concave shape of the head make it (seemingly) impossible! Once you break through from one side, the bit bends and conforms to the shape of head and promptly snaps off. I've gone through 3 bits and am giving up unless someone else has a solution?

the obvious is replace the bolt with a standard hex head one. I found some at TSC last night, but they're 2" and this caliper bolt appears to be a 2.25.

Can you drill through from the opposite side as well?

Or are you saying that as soon as you break through, the bit snaps? If that's the case, maybe you can drill most of the way through, and then drill a tiny amount perpendicular to the hole to complete it.

Yeah. I'm not real bright (evidently), and by the time I got the idea to just drill on the other side occurred to me, I had snapped all my bits.

That's probably the best option. I was kinda just hoping that someone would say "hey, try these superdeluxe blahblah bits, they're awesome"...

They don't snap immediately, but it's pretty quick.

Andy:

Why are you going thru all that grief? If a caliper (or anything else for that matter) is tightened/torqued properly, why would it come loose?

Just put some blue (removable) Loctite on it and go ride!

I was doing it to wire up the little hairpin cotter pins to something. I've been reading about them getting accidentally picked out by brush and what-not.

Also, I'm nursing a concussion and looking for things to do. lol.

I use small wire ties to hold the little cotter pins in place; one on each side of the retainer pin and one to hold them all in place

All other bolts will stay in place with blue or red Loctite.

safety wire

the guys are correct, a number of the sumo series want all critical bolts safety wired. rad cap, drain bolt, coolant hoses.... a good way to get to know your bike is take a weekend and safety wire it. proper speed on the drill press, with a quality cutting oi, No wd-40.. i went to a 12 point bolt for the rotor on my SMR... as it comes with flush head allens...