Broken bolt in stem

I have a somewhat tricky problem, 'tricky' is probably the understatement of the Century, the bolt cracked while riding the bike, and it look like it's made of aluminum than steel;

As far as I can, the only way I can remove the stem is to cut it and retreat it damaging the stem, there's no way the allen key can 'grip' to the bolt to loosen it.

However I was told that if I carefully drill the offending disintegrated bolt that'd put the Rubble to shame, I should be able to save the stem from it's impending doom, is there another method, or is that the only best way to do it?

I have to retire the frame temporary for safety reason until I can removed the stem.

Drill it out and tap a screw/bolt into it reverse to thread and turn slowly.....

Don't envy you though, that's a right pain in the arse

Solder an allen key to the bolt.

epoxy it? allan key to bolt?

Cut it off and be done in 5 minutes.

Stems are cheap.

Cut it off and be done in 5 minutes.

Stems are cheap.

Naturally I'd agree, but the Cinelli one are a little hard to find for cheap nowadays, especially since the handlebar I have is those Cinelli type.

I've got three sitting on my kitchen table.

What size you need?

If you have a drill and bits then try that first.

But don't spend more time and money than necessary.

A Cinelli 1R at 110mm (that's the one in picture), I'm a believer of make do and mend thought, if it is possible to save the stem, then it's worth it, if not, cut it off.

Is it a friction fit job at the end of the bolt? You're gonna have to give it a whack maybe too to get it moving down the bottom?

Drill out the top of the bolt. Once the bolt head is gone, tap the the bolt down to free the stem. Should be a pretty easy job, I'd have thought?

That's a lot of drilling, and it would mean being extra careful to not damage the stem, but yeah, I'm with you on that.

If it really is an ally bolt, then the drilling's going to be a piece of cake. Like a knife through soft butter if you have a good drill bit and a steady hand. Although go gently, you don't want to go through the bottom of the head and ruin the stem.

However, you might try the epoxy trick first.

How did you manage breaking it Ed?

I'd first try cutting a piece from a steel allen bolt head to drop in where the missing piece is,pack it in tight with coke can shim against socket in stem ,with allen key already in place,(maybe araldite in allen socket/allen key interface) and try to gently undo bolt.Probably won't work but I'd try it

Start drilling 5mm or 6mm diam.
There are bits, fairly cheap, conical, that you can turn into the drilled hole with left turns. (EDIT: just learned that you guys call it an easy-out ;-) )
Once they get grip, they more or less "eat" into the bolt and loosen it.
The bolt is gone anyway. The conical bit may do the job only once.
What you need for the rest is a new bolt for your stem. And don't forget to put grease on all surfaces.

Get an easy-out, drill a small pilot hole, then use the easy-out to get the bolt out.. easy and no damage to stem.

what is a easy-out? any pics?

what is a easy-out? any pics?

http://www.screwfix.com/sfd/i/cat/99/p1410699_l.jpg

Screw extractors.

Ed as mentioned earlier I would drill it out, should be easy enough if you have the right tools.

the whole bike's fucked, throw it in the bin.

then get out and ride!

another bike, obviously

http://www.screwfix.com/sfd/i/cat/99/p1410699_l.jpg

Screw extractors.

Yeah what he said... saved my life more than once.

I don't think drilling will help as the expander part of the stem will still be stuck? I think your best bet is to try to weld/bond an allen key in there.

what type/brand of allen key were you using?

sorry if i missed something.

How would that make a difference thought? those reliable park tools one.

Drill the head off the bolt, place a rod (eg another bolt) on top of what is left of the original one and give it a good whack with a hammer. I can't see any reason why it wouldn't release the stem.