snapped stem bolt

wersal gummage

so changed the stem on the bike there (have done it before on another bike).

new stem on, tightening everything up slowly, bit by bit (being careful because i'm using titanium bolts - but not careful enough because i dont have a torque wrench).

snap.

one of the bolts snapped in half. the head has obviously come away. however, the other half of the bolt is left in the back of the stem bracket and it is flush - i.e. none of it sticking out to even try and twist it out with a long nose pliers.

so what to do ????? throw away a lovely new stem ?????? :mad:

any ideas how to get this bit of a bolt out ?

thanks.


edit: i'm thinking of drilling a tiny hole into whats left of the bolt, so i might be able to get something into the hole to unscrew it a bit ???? obviously with the stem off the bike.

Morgan

You need a bolt extractor (easy-out).

http://www.brandsplace.com/tool-hand-tools-screw-and-bolt-extractors.html

Chips Lovell

Been there, done that. I ended up buying a new stem.

IM0

wersal gummage wrote: »

edit: i'm thinking of drilling a tiny hole into whats left of the bolt, so i might be able to get something into the hole to unscrew it a bit ????

I was going to suggest that too. you need a small self tapping screw for that. Or tap out the small hole manually and screw another screw in there with a rediculously strong glue on it, then hope that whatever you are going to attach to that that the bond holds to apply enough torque before the bond breaks :rolleyes:

good luck, a nice project for the weekend

dave2pvd

Morgan wrote: »

You need a bolt extractor (easy-out).

http://www.brandsplace.com/tool-hand-tools-screw-and-bolt-extractors.html

It will work. But you need to make sure you fixture the stem properly.

• If you can, try to find a drill press.
• Carefully clamp the stem in a vise (preferably on the work surface of the drill press).
• Carefully drill a small pilot hole in the sheared bolt end (maybe 2mm). Note: carefully.
• Increase the pilot hole to the recommended size for the easy-out you need to use. The correct size will be indicated on the easy-out package.
• Using the correct easy-out in a T-handle, remove the bolt end.

dave2pvd

dave2pvd wrote: »

It will work. But you need to make sure you fixture the stem properly. Trying to do this while it is on the bike is a recipe for disaster.

• If you can, try to find a drill press.
• Carefully clamp the stem in a vise (preferably on the work surface of the drill press).
• Carefully drill a small pilot hole in the sheared bolt end (maybe 2mm). Note: carefully.
• Increase the pilot hole to the recommended size for the easy-out you need to use. The correct size will be indicated on the easy-out package.
• Using the correct easy-out in a T-handle, remove the bolt end.

• Replace the broken bolt with a high-tensile stainless steel one. Make sure it is high-tensile.
• Don't do any of this until you have acquired a torque wrench and Allen socket set (mandatory for lightweight bikes, IMO).
• Good luck.

greenrocket

not really knowing much about bike maintenance and knowing a bit about heavy industry maintenance i have to say that what dave2pvd said might work but i wouldnt be that confident. a new stem may be the easiest way.

wersal gummage

el tonto wrote: »

Been there, done that. I ended up buying a new stem.

yeah well me too by the looks of it

dave2pvd wrote: »

Carefully drill a small pilot hole in the sheared bolt end (maybe 2mm). Note: carefully.

thanks for that dave. i actually went ahead before i saw your advice and drilled a 2mm hole in the sheared bolt. unfortunately the titanium bolt is weak enough to snap but strong enough to make sh*t of all my small drill bits (aldi - most of my tools are actually decent but i cheaped out on a few aldi drill bits - never again). so i broke loads of them - as the bolt was stronger than the drill bits it pushed the bit over a few times and damaged the thread. so yeah, the stem is knackered.

wont ever be using titanium bolts again. will pick up a torque wrench too. expensive lesson learned.

it was this stem by the way, not that it matters:

Hermy

I did something similar with a Race Face stem I bought in Cycleways.
I brought it back to the shop and explained to them that I had followed the installation instructions including using a torque wrench.
They replaced it.

fishfoodie

wersal gummage wrote: »

yeah well me too by the looks of it



thanks for that dave. i actually went ahead before i saw your advice and drilled a 2mm hole in the sheared bolt. unfortunately the titanium bolt is weak enough to snap but strong enough to make sh*t of all my small drill bits (aldi - most of my tools are actually decent but i cheaped out on a few aldi drill bits - never again). so i broke loads of them - as the bolt was stronger than the drill bits it pushed the bit over a few times and damaged the thread. so yeah, the stem is knackered.

wont ever be using titanium bolts again. will pick up a torque wrench too. expensive lesson learned.

it was this stem by the way, not that it matters:

Sorry, only just saw this thread, or I could have saved you the effort.

As you've discovered Ti is incredibly hard, but can be very brittle. So trying to drill small diameter holes in it requires special drill bits.

You might have had more success putting some impact glue on the end of a thing steel rod, & then pressing that end of the rod on the broken end of the bolt.

Once it dries, you might be able to unscrew the bolt enough to get a pliers on it.

cdaly_

Drill slipping into the threads may make the glue method fail but it's worth a try. If you do get it out, the thread damage probably won't be bad enough to need a new stem.

I once had a bolt snap off in a car's cylinder head. Didn't want to remove the head so I welded a blob of metal onto the broken bit of bolt and then turned that with a vice-grip.

Single Malt

fishfoodie wrote: »

Sorry, only just saw this thread, or I could have saved you the effort.

As you've discovered Ti is incredibly hard, but can be very brittle. So trying to drill small diameter holes in it requires special drill bits.

You might have had more success putting some impact glue on the end of a thing steel rod, & then pressing that end of the rod on the broken end of the bolt.

Once it dries, you might be able to unscrew the bolt enough to get a pliers on it.

I was going to say GL drilling Ti. the glue should work, as the bolt should unthread very easy (unless you really screwed up the install).