Torque wrenches - m...
 

[Closed] Torque wrenches - merits of beam vs ratchet types?

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There's some good deals around on the Park Tools TW-2 wrench, but what are the pros and cons of this beam type one vs a ratcheting wrench like the TW-5?

I can see that the beam one gives you infinite adjustment, but I dont suppose that is really necessary, as 0.4nm steps are probably OK.

cheers


 
Posted : 28/11/2012 10:39 am
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Mine is a micrometer adjustment on my socket wrench, do some have stepped adjusters?

Beam types are usualy beter than guessing, but not generaly as accurate. But unlikely to be an issue on a bike, even with carbon bits.


 
Posted : 28/11/2012 10:44 am
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I've heard that beam ones are more accurate unless you're buying v expensive ratchet ones and regularly calibrating them.


 
Posted : 28/11/2012 11:00 am
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Chief - that's what I'd heard, plus you have the convenience of not having to actual set them to a desired torque (though I guess that also allows for accidental over tightening too)


 
Posted : 28/11/2012 11:02 am
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Nothing to go wrong with beam type, so very reliable, but no use if you can't get to see the torque scale easily.


 
Posted : 28/11/2012 11:02 am
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Worth a look,

http://suite101.com/article/how-to-choose-adustable-beam-torque-wrenches-a169188

Plus
'A beam-type torque wrench measures the flex in the beam of the wrench as force is applied to a bolt to measure the torque. With a gauge like this it’s important you keep your head over the markings and not at an angle in order to get an accurate reading. It’s rare to see this type of torque wrench in a professional shop any more.'

http://www.circletrack.com/techarticles/ctrp_1111_torque_wrench_myths/photo_05.html#ixzz2DVxGisSt


 
Posted : 28/11/2012 11:03 am
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Sheldon had the best guide for beam torque wrenches;

[img] [/img]


 
Posted : 28/11/2012 11:06 am
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Secondary question - Park Tools TW-1 vs TW2

TW-1 has a range up to 7nm, the bolt I think I stripped was a Hope banjo which I now know should be tightened to 8nm. So I'd need the TW-2.

But looking at the TW-2, it goes to 70nm, so doesnt look seem precise for relatively low torques. The scale is in 5nm increments, so that means human error in reading it is going to negate any claims that it only has a 2% inaccuracy.

Maybe I've answered my own question...


 
Posted : 28/11/2012 11:17 am
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