Micrometer Torque for Hollotech II BB

wolfsbane2k
wolfsbane2k Posts: 3,056
edited September 2016 in Workshop
Hi.

I need a new torque wrench to meet the needs of my BB, which has a 0.7 - 1.5nm range.
My existing torque wrenches are 2-24nm and 20-80nm , so not much use.

What does anyone else use for checking in this range? I can't find anything cheapish (<30) that I'd trust in this range anyway!

Ta
Intent on Cycling Commuting on a budget, but keep on breaking/crashing/finding nice stuff to buy.
Bike 1 (Broken) - Bike 2(Borked) - Bike 3(broken spokes) - Bike 4( Needs Work) - Bike 5 (in bits) - Bike 6* ...

Comments

  • imposter2.0
    imposter2.0 Posts: 12,028
    What part of an HT2 BB requires such a low torque setting? I've fitted/re-fitted these BBs many times and never used a torque wrench on any part of it...
  • wolfsbane2k
    wolfsbane2k Posts: 3,056
    Imposter wrote:
    What part of an HT2 BB requires such a low torque setting? I've fitted/re-fitted these BBs many times and never used a torque wrench on any part of it...

    I've got a prowheel 721 crankset which requires it that low for the bearing pre-load.
    Intent on Cycling Commuting on a budget, but keep on breaking/crashing/finding nice stuff to buy.
    Bike 1 (Broken) - Bike 2(Borked) - Bike 3(broken spokes) - Bike 4( Needs Work) - Bike 5 (in bits) - Bike 6* ...
  • imposter2.0
    imposter2.0 Posts: 12,028
    No torque setting is needed for the bearing preload on HT2 - just nip up the centre cap as necessary. There's a reason Shimano tools are fitted with a little detachable finger/thumb tool for this purpose...
  • crankycrank
    crankycrank Posts: 1,830
    Bearing pre-load can be done by feel easily. Tighten as much as you can by hand, spin the crank a few times, back off until it feels too loose and then tighten again to remove play. A torque wrench with that low of torque can easily be wrong just by the differences in resistance from dirty vs. clean and lubed threads on the tension nut. Develop your feel just as thousands of bike mechanics do every day installing the HT2's. That is why Shimano makes a plastic tool for hand tightening.
  • wolfsbane2k
    wolfsbane2k Posts: 3,056
    Imposter wrote:
    No torque setting is needed for the bearing preload on HT2 - just nip up the centre cap as necessary. There's a reason Shimano tools are fitted with a little detachable finger/thumb tool for this purpose...

    Aye, I kinda agree with you, and have done "by feel" in the past, but don't feel it's right at the moment.
    The spec sheet for the non-shimano BB & crankset I've got specify that torque, so I'd like something to test myself against to learn that value, am currently making my own from a measured allan key and a small weight.
    Intent on Cycling Commuting on a budget, but keep on breaking/crashing/finding nice stuff to buy.
    Bike 1 (Broken) - Bike 2(Borked) - Bike 3(broken spokes) - Bike 4( Needs Work) - Bike 5 (in bits) - Bike 6* ...
  • imposter2.0
    imposter2.0 Posts: 12,028
    Honestly, a torque setting for preloading HT2 bearings is pointless - a bit like torquing the top cap on a headset, there's just no need and it is equally as pointless.

    But if you want to waste your time building a device to measure something that will probably differ necessarily with each installation, then fill your boots.
  • trailflow
    trailflow Posts: 1,311
    What are you trying to achieve ? Perfect bearing performance ? How will you ever know ?

    All you need to do is eliminate any play. The micro differences of preload either way will not make any difference to the bearing performance as they are within their own container. The plastic end caps are absorbing most of the preload forces.

    Prowheel are trolling you.
  • wolfsbane2k
    wolfsbane2k Posts: 3,056
    What i'm trying to achieve is being a complete cack handed idiot who gets through BBs like there's no tomorrow.
    And because i've only got my bike to play with, the comparision of the right point is hard to judge, so i'm trying to find something comparative.
    Intent on Cycling Commuting on a budget, but keep on breaking/crashing/finding nice stuff to buy.
    Bike 1 (Broken) - Bike 2(Borked) - Bike 3(broken spokes) - Bike 4( Needs Work) - Bike 5 (in bits) - Bike 6* ...
  • imposter2.0
    imposter2.0 Posts: 12,028
    It's incredibly hard (to the point of being practically impossible) to put excessive preload on HT2 BB bearings if you just use the hand tool which Shimano recommends. You would have to be the incredible hulk or robocop to over-tighten the bearings using that device.
  • wolfsbane2k
    wolfsbane2k Posts: 3,056
    Imposter wrote:
    It's incredibly hard (to the point of being practically impossible) to put excessive preload on HT2 BB bearings if you just use the hand tool which Shimano recommends. You would have to be the incredible hulk or robocop to over-tighten the bearings using that device.

    Ok, although i've not got a Shimano Hollowtech, I understand what your saying, thanks.
    Intent on Cycling Commuting on a budget, but keep on breaking/crashing/finding nice stuff to buy.
    Bike 1 (Broken) - Bike 2(Borked) - Bike 3(broken spokes) - Bike 4( Needs Work) - Bike 5 (in bits) - Bike 6* ...
  • imposter2.0
    imposter2.0 Posts: 12,028
    Wolfsbane2k wrote:
    Imposter wrote:
    It's incredibly hard (to the point of being practically impossible) to put excessive preload on HT2 BB bearings if you just use the hand tool which Shimano recommends. You would have to be the incredible hulk or robocop to over-tighten the bearings using that device.

    Ok, although i've not got a Shimano Hollowtech, I understand what your saying, thanks.

    Not sure what you mean - your thread title has the words Hollo(w)tech II in it. Hollowtech 2 BBs are what we are discussing here.
  • wolfsbane2k
    wolfsbane2k Posts: 3,056
    Imposter wrote:
    Wolfsbane2k wrote:
    Imposter wrote:
    It's incredibly hard (to the point of being practically impossible) to put excessive preload on HT2 BB bearings if you just use the hand tool which Shimano recommends. You would have to be the incredible hulk or robocop to over-tighten the bearings using that device.

    Ok, although i've not got a Shimano Hollowtech, I understand what your saying, thanks.

    Not sure what you mean - your thread title has the words Hollo(w)tech II in it. Hollowtech 2 BBs are what we are discussing here.

    Ah, it's probably a misuse of the term. I've got a "Hollowtech II compatible" Bottom bracket, but am looking to order a spare shimano one currently, on the premise that the original cranks will work with the shimano BB.
    Intent on Cycling Commuting on a budget, but keep on breaking/crashing/finding nice stuff to buy.
    Bike 1 (Broken) - Bike 2(Borked) - Bike 3(broken spokes) - Bike 4( Needs Work) - Bike 5 (in bits) - Bike 6* ...
  • imposter2.0
    imposter2.0 Posts: 12,028
    Same thing. Either way, you don't need a torque wrench.
  • TheRealGuybrush
    TheRealGuybrush Posts: 125
    In answer to your original question - a British company called Norbar make a torque screwdriver with a range of 0.6-1.5Nm.

    You're going to be paying around £100 for it though. https://www.amazon.co.uk/Norbar-Torque-Screwdriver-0-3-1-5Nm-4in/dp/B0098HRTH8/ref=sr_1_5?ie=UTF8&qid=1473485345&sr=8-5&keywords=norbar+screwdriver

    Looking at the cost of the Prowhell 721 - I wouldn't say it's a particularly high performance product, and that level of installation might be a bit over the top.
  • wolfsbane2k
    wolfsbane2k Posts: 3,056
    TheRealGuybrush wrote:
    In answer to your original question - a British company called Norbar make a torque screwdriver with a range of 0.6-1.5Nm.

    You're going to be paying around £100 for it though. https://www.amazon.co.uk/Norbar-Torque-Screwdriver-0-3-1-5Nm-4in/dp/B0098HRTH8/ref=sr_1_5?ie=UTF8&qid=1473485345&sr=8-5&keywords=norbar+screwdriver

    Looking at the cost of the Prowhell 721 - I wouldn't say it's a particularly high performance product, and that level of installation might be a bit over the top.

    Thanks! I did see that, but as you say I didn't think it worthwhile when I could get a 5700 complete crankswt for that much, which then wouldnt need it.
    Intent on Cycling Commuting on a budget, but keep on breaking/crashing/finding nice stuff to buy.
    Bike 1 (Broken) - Bike 2(Borked) - Bike 3(broken spokes) - Bike 4( Needs Work) - Bike 5 (in bits) - Bike 6* ...
  • imposter2.0
    imposter2.0 Posts: 12,028
    Wolfsbane2k wrote:
    TheRealGuybrush wrote:
    In answer to your original question - a British company called Norbar make a torque screwdriver with a range of 0.6-1.5Nm.

    You're going to be paying around £100 for it though. https://www.amazon.co.uk/Norbar-Torque-Screwdriver-0-3-1-5Nm-4in/dp/B0098HRTH8/ref=sr_1_5?ie=UTF8&qid=1473485345&sr=8-5&keywords=norbar+screwdriver

    Looking at the cost of the Prowhell 721 - I wouldn't say it's a particularly high performance product, and that level of installation might be a bit over the top.

    Thanks! I did see that, but as you say I didn't think it worthwhile when I could get a 5700 complete crankswt for that much, which then wouldnt need it.
    The prowheel crank doesn't need it either. Think about it..

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