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Tightening bolts on stem and handlebar clamp

Discussion in 'Bicycle Mechanics and Repairs' started by palinurus, 18 Mar 2008.

  1. palinurus

    palinurus Guru

    I'm going to try a shorter stem on one of my bikes. Now I've done this before, and often stems have the correct torque printed on 'em at each end. I just do them up until I'm satisfied- basically somewhere between "it isn't loose" and "I'm going red in the face". But closer to "it isn't loose". Only not that close.

    Must be a better way; hence this post.

    Might well be relevant: no carbon bits involved here.
  2. hubgearfreak

    hubgearfreak Über Member

    if you've gone past the "a bit loose" stage in the past and had nothing fall off you've got it about right:biggrin:

    personally, i'm a bugger for over tightening stuff:blush:

    i once put the front suspension on my beach buggy with a torque wrench, set to the right setting, but it was no way tight enough for my mind, so i gave it another turn or two on each bolt, and haven't used the TW since:laugh:
  3. e-rider

    e-rider crappy member

    South West
    Is it a A-headset type stem? If so, the top bolt is for tensioning and should be adjusted carefully. All other bolts should, in my opinion, be done up very tight - without breaking them (grease every bolt first). Some lightweight components (Hope Hed Doctor) are well know for breaking easily, but anything with stainless steel bolts should be pretty strong.

    I agree with the comment about Torque wrenches - set them to the manufacturers recommendations and they never seem to be tight enough!
  4. palinurus

    palinurus Guru

    Aheadset, yup. Not worried about the top bolt, I know how to deal with that. Just wondering how I gauge how tight to do up the clamp bolts which attach it to the steerer tube and the bars. Useful comments, thanks.
  5. Danny

    Danny Legendary Member

    For the benefit of those of us with limited mechanical knowledge could someone explain what the heck a torque wrench is.

    And do I need to have one? I seem to have managed to maintain my bike reasonably well over the years without even knowing that such a thing exists.
  6. Mister Paul

    Mister Paul Honky

    North Somerset
  7. gbb

    gbb Legendary Member

    99% of things can be tightened by 'feel'...you know when its tight.
    I always work on the principle of tightening till its just gone tight...then give it a 'little' bit more.

    Trouble is, you cant explain it in a way...it's just experience.

    Beware, you can easily strip the threads in alloy...i always go steady with alloy.

    I've tightened THOUSANDS of bolts...never used a torque wrench.
  8. palinurus

    palinurus Guru

    I'll trust my experience then, I think I suffered a temporary bout of self-doubt regarding my bolt-tightening ability brought on by the torque recommendations printed on my stem'n'bars.
  9. Monty Dog

    Monty Dog New Member

    Get yourself a Ritchey Torque Key - about £12 and eliminate the risk of breaking an expensive component. Having myself assembled literally thousand of high-tech products in safety critical applications, I still use a torque wrench despite having a well-calibrated wrist - but it's not calibrated well enough for 4-bolt faceplates on stems. Working in aerospace, we'd sack someone who blatently disregarded the assembly procedures which includes the mandatory use of a torque wrench in many applications.
  10. fossyant

    fossyant Ride It Like You Stole It!

    South Manchester
    Those of us with steel and alloy components can get away without using a torque wrench....add in composites then you need them I'd say.
  11. Zoiders

    Zoiders New Member

    Ice Station Zebra

    You speak of the method known as the "R.F.T" tourque setting

    I know it well and use it often
  12. fossyant

    fossyant Ride It Like You Stole It!

    South Manchester
  13. robbarker

    robbarker Well-Known Member

    Lots of people, including a fair few bike shop mechanics, don't routinely use torque wrenches. The world of cycling is full of stripped alloy threads, loose headsets, clicky bottom brackets, groaning cranks and slipping seatposts. This is not a coincidence.

    If you want to do the job properly, you need at least two torque wrenches - a little one for the smaller fastners and a meatier one for things like crank bolts.
  14. gbb

    gbb Legendary Member

    I'd agree...and disagree :?:
    If there is any uncertainty or lack of experience...get a torque wrench if you want to be sure.
    But even that wont stop you stripping previously damaged threads.... if you put blind faith in a torque wrench and the threads are damaged...you may still strip the threads.
    Experience MAY tell you not to go too tight (by hand )with damaged threads, but thats down to luck as well.

    Its a matter of degree IMO.
    If you own an expensive carbon jobby...i think even i'd get a torque wrench.
    If its a hack or moderately cheap bike, i'd tighten by hand and feel.

    Theres also the point if you use a torque wrench, you'll NEVER get to know how to tighten bolts by feel.
    Its not rocket science...Cranks for instance (although the same applies to almost any application) . Tighten them by feel. Not too tight you have to strain. You just need to check and maybe check again in a few days or weeks to see if you did them tight enough.

    But then :rolleyes:i know some engineers who tighten things up like their lives depend on it...and accordingly strip threads occasionally.

    Theres no easy answer. (This is not aimed at anyone specifically, just an observation) Think about what you're doing. Think how tight that feels. Go back and check it after some use. Check it again if neccessary. In other words....learn. Most of us are quite capable. We just need to learn...it takes a little practice and time, thats all.
  15. robbarker

    robbarker Well-Known Member

    On the contrary, you learn to feel exactly how tight different types of fastners should be tightened.

    I'm quite confident that I could get most fastners on a bike about right. I choose not leave it to educated guesswork though, I use a torque wrench so I know I've done it properly. This is important to me when working on other people's bikes, as well as my own.