Broken Stem??

markpotts147
markpotts147 Posts: 100
edited March 2011 in Road beginners
I bought a new stem from Chain Reaction (very good service by the way). Was fitting it this morning and over tightened one of the screws. As a result SNAP! Half the screw is in the bin and half is stuck in the stem. Is this still safe to use or should I put my old one back on and pay £55 for another :cry::cry:

5561038200_dbf0f5a3f3.jpg
IMG00273-20110326-1146 by mp147, on Flickr

Comments

  • 5pudgun
    5pudgun Posts: 402
    Can you not remove the broken bolt and replace it. There are tools available to do this
  • pingpong
    pingpong Posts: 97
    Why would you need to buy another stem? Just take the snapped screw out and replace......Torque Wrench comes to mind, oh I would not go out on the bike with only 3 screws holding the handle bars in place, I would not feel comfortable about it, but then that's just me :)
  • andyrr
    andyrr Posts: 1,823
    Don't use the stem in it's current state - I realised I'd ridden for a short time with 3 out of 4 bolts in place (don't know where the 4th one went) and the face plate fractured. Was a Deda Newton. Too much stress will be placed on the remaining bolts and the fact that the stem/bar interface is not as designed with nice equal forces all across it.
  • Stewie Griffin
    Stewie Griffin Posts: 4,330
    It's because you put the front bit on upside-down.
  • sungod
    sungod Posts: 17,411
    i've done the same - at which point i realised my torque wrench had gone gaga, luckily in warranty

    to remove the piece of bolt, take off the faceplate

    if there's enough sticking out, slot it with a hacksaw and use a screwdriver, or maybe use pliers to turn it

    otherwise, drill a hole in the centre of the bolt, then either use a screw extractor to remove it, or put a small bolt into the hole and use that to drive the bolt out through the other side of the stem
    my bike - faster than god's and twice as shiny
  • c0ugars
    c0ugars Posts: 202
    You dont need to buy a new stem, just remove half the screw, i would do this by drilling it out.
  • rake
    rake Posts: 3,204
    torque wrenches are made for people like you (no maintenance skills). i dredd to think how tight it was to snap the bolt.
  • Monty Dog
    Monty Dog Posts: 20,614
    Trying to drill out the screw might be tricky unless you have access to a pillar drill. It is not under tension and you may be able to unscrew it using a scribe or fine-pointed tool to try and turn it. You don't need a full-blow torque wrench, just a Ritchey Torqkey for £12 which is preset to the right torque for bars and stems.
    Make mine an Italian, with Campagnolo on the side..
  • ajb72
    ajb72 Posts: 1,178
    rake wrote:
    torque wrenches are made for people like you (no maintenance skills). i dredd to think how tight it was to snap the bolt.

    Crikey, that's a but harsh isn't it?! I've been building and maintaining bikes for 10 years and I use a torque wrench. Some of these tightening recommendations are pretty low, I defy you to tell the difference between 5, 6 and 8 nm of torque with an allen key and your bare hands only.

    That aside, it must indeed have been severely over tightened.
  • brin
    brin Posts: 1,122
    Stewie Griffin wrote:
    It's because you put the front bit on upside-down.
    :lol::lol:
  • rake
    rake Posts: 3,204
    edited March 2011
    ajb72 wrote:
    rake wrote:
    torque wrenches are made for people like you (no maintenance skills). i dredd to think how tight it was to snap the bolt.

    Crikey, that's a but harsh isn't it?! I've been building and maintaining bikes for 10 years and I use a torque wrench. Some of these tightening recommendations are pretty low, I defy you to tell the difference between 5, 6 and 8 nm of torque with an allen key and your bare hands only.

    That aside, it must indeed have been severely over tightened.

    ok, i retract. carry on breaking bolts :lol:
  • stevec205gti
    stevec205gti Posts: 366
    Another thing you can try if it's recessed in the hole is a smaller flat ended piece of metal/plastic and some glue - don't use too much as you don't want it to spread and run into the thread. I'd view drilling it out as a last resort
    Has the head wind picked up or the tail wind dropped off???
  • sungod
    sungod Posts: 17,411
    if you can't get it out with persuasion, use the screw extractor

    they only cost 2-3 quid, and once you've got one sod's law should help protect you from breaking any more bolts :-)

    i've done it on a stem bolt with a handheld powerdrill

    you need a 2mm drill bit, followed by a no. 1 screw extractor, it's a 5 minute job

    just make sure you get the drill bit centered and start slowly and along the axis of the bolt, you need to get the hole about 7-8mm deep

    then just put the extractor in and turn anticlockwise, it'll bite into the bolt and unscrew it
    my bike - faster than god's and twice as shiny

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