Torque wrench

veterangaz
veterangaz Posts: 79
edited August 2014 in Workshop
I have been looking in to buying a torque wrench but don't want to waste the money if I do not use it correctly. From what I gather, you can use it to correctly tighten bolts to the right amount. How do I find the correct setting to tighten to though, I no longer have the manual that came with my bike so I guess a torque wrench would be pointless if I do not know the correct amount to set it to?

Comments

  • Old_Timer
    Old_Timer Posts: 262
    You could go on line to the bicycle's manufacturers site and get the values from their technical page, or ask in at the shop. Most torque values are based on the bolt's size/diameter and application, carbon fiber contact can change that so as not to shatter the fiber and matrix structure.

    Most stems have their torque values on them and a lot of the seat pillar clamps are 5N-m or 6N-m. I have both a torque wrench, and a torque key from Ritchey, that is preset at 5N-m and has several tips to choose from, might be a good solution once you get the torque values you need.
    Lets just got for a ride, the heck with all this stuff...
  • Bought one recently from Planet X for £35. Cheapest one around I found.
  • Secteur
    Secteur Posts: 1,971
    I have the Park Tools one (actually I have both the small and large one), and it's great little tool (though as per my carbon seat post in this forum, it may not be 100% accurate but I have no way of knowing).

    I feel very confident tightening bolts now, where before I was constantly worried about over-tightening things, which can obviously be damaging.

    About once a month, I go over all the bolts on the bike (and cleats) and check everything is nice and tight.

    Definitely a sound investment for a carbon bike / parts. Expensive but I would never be without mine. I regularly tinker with my bike and use it far more than I thought I would.

    As above, most torque values are printed on the part, but these are easily found on a search on the manufacturers website (and Park Tools have a handy section in their book and their website with values)

    Park Torque Value Advice:
    http://www.parktool.com/blog/repair-hel ... d-concepts

    My Park Wrenches:
    http://www.parktool.com/product/ratchet ... rench-tw-5
    http://www.parktool.com/product/ratchet ... rench-tw-6
    http://www.parktool.com/product/socket- ... -set-sbs-1
  • Zerotails99
    Zerotails99 Posts: 127
    I got a torque wrench from halfords. I think its a topeak or park tools. I used it just once and it felt I was over tightening when following the recomended torque. Its hard to tell if these wrenches are correctly calibrated so I just do it the old fashioned way and go with feel.
  • gloomyandy
    gloomyandy Posts: 520
    Remember that often the values printed on components are the maximum torque allowed, you often do not need anything like that value to have the bars/seatpost etc. to hold in position. Use of things like carbon paste will often lower the torque needed for such items. Best if possible to read the actual technical docs. Some items like some SRAM chainsets have specific torque values for certain bolts.
  • macleod113
    macleod113 Posts: 560
    I have had one for a few months now. £35 from Wheelies I think. I started tinkering and ended up rounding off a bolt on the seat clamp. after this point I found the instructions that advised me to calibrate the thing first.

    you live and learn..... :D
    Cube Cross 2016
    Willier GTR 2014
  • Well I went ahead and brought one off wiggle. It does feel like I am tightening the parts a lot more than previously and I am using it correctly. Hopefully it is calibrated correctly.
  • sungod
    sungod Posts: 16,438
    as above, the marked torque is typically the maximum, assume it's based on dry clean threads, with lubricated threads the limit will be significantly lower

    if a part is marked "8Nm" but is tight enough at 6Nm then that's as far as you need to go
    my bike - faster than god's and twice as shiny
  • davem399
    davem399 Posts: 269
    I bought a Sealey 3/8" drive one from Amazon (currently around £33) complete with calibration certificate.