tim-b wrote:I bought a set of allen key sockets for not much, at bicycle torques you won't break many Regards tim-b
And if it is just the one allen key size you want for the torque wrench , and you have a spare allen key of that size; then cut the allen key in half and then fit the allen key into a socket and that socket into the wrench.
To be honest I think that a shaped tray with places for all the items is a very good reason to buy something like that. Rather than have all the separate tools and bits rattling round in a toolbox.
Torque wrenches are more accurate in the middle of their range
They should be accurate to less than +/-4% at ISO set increments within their range. It's fair to say that the low end will be tighter with a tad* over 0.3Nm tolerance range at 4Nm, whereas at 20Nm the tolerance range is around 1.6Nm and so the mid to high range has a wider tolerance band to hit.
*tad is an ISO-recognised unit
My experience with Norbar torque wrenches is that the manufacturer's certification is accurate and remains so. Some other brands are less so, albeit on my small unrepresentative sample. Spend a bit more, you know you're worth it Regards tim-b
This isn't too bad quality, unfortunately has gone up in price again, last week when I bought it it was £25. A beam wrench doesn't need calibration so you could consider that too. I'd go for a 1/4" drive for the most useful range on a bike. 40nm for crank bolts is one of the few higher torques needed, and just 'pretty tight' is good enough for me for that.
Torque wrenches are supposed to be calibrated about every 5,000 clicks, so as long as you wind it down to about 2nm after use every time and don't drop it, should last a good while.
Trigger wrote:I notice deflecting beam type torque wrenches aren't very common here, they seem very much an American thing. Strange as they seem a decent option.
Park do them, expensive of course and they're a bit of a hassle to use at higher torques especially as you need to look at the dial square on as you're hanging off the beam.
One of these is in my toolbox and had a lot of use when building up my latest bike with carbon forks, my first experience of full carbon forks. In use I was quite surprised how little some bolts are tightened up when they get to the required torque.
Trigger wrote:I notice deflecting beam type torque wrenches aren't very common here, they seem very much an American thing. Strange as they seem a decent option.
Topeak do one for less than £20 including the most common hex bits, the range is enough for most small cycle fittings. I read a review that slated it for inaccuracy, though mine is consistent with my cheapish ratchet torque wrench, it's possible but unlikely they're both equally wrong.
Hi Whatever you choose, after you set a torque "click" the wrench off a couple of times on a dummy load before taking it to the actual fastener; torque wrenches sometimes start high until the mechanism settles. A selection of fasteners in a vice or on a piece of angle iron will do There shouldn't be a problem with leaving the torque wrench set for a day of fettling but I always wind mine back to the low mark overnight but not to zero. 10 useful things link Regards tim-b
IME unless you are a professional cycle mechanic the intervals between uses of your torque wrench will be long enough that the mechanism in a click-type wrench will have become sticky or even have gummed up through lack of use and you won't get accurate torque settings out of it unless the mechanism is relubed and/or 'exercised' as tim describes above.
For this reason (and despite that they are a little bit more awkward to use(*) I would suggest deflecting beam type wrench(es) are arguably most appropriate for occasional use. A good combination would be a small one such as the topeak T-bar for fasteners up to M6 thread and a larger one (with a 3/8" or 1/2" square drive) for everything bigger. With this setup you have no worries about calibration; both are guaranteed to be linear, and you can check the calibration of the Topeak (which will vary with the position of the scale on the torsion bar) against the larger wrench whenever you like.
(*) you need to be able to read the scale; in practice this isn't ever a problem when working on a bicycle, because you have good access to all the fasteners you need to. On the plus side there are no settings to make, check or get wrong, so you will usually be faster using a deflecting beam wrench on individual bolts, or pairs of bolts; click-type wrenches really come into their own when torqueing multiple similar fasteners, which is a situation that never arises on a bicycle.
looks like a reasonable alternative to the Topeak and similar for low torque values/occasional use; on the plus side it will store easily, but on the minus side it isn't as easy to use as a T-bar.
I've often wondered how low setting torque wrenches deal with variations in thread tolerances. I was in a well known cycle dealer's shop when a woman came in with her recently purchased bike bike. The front changer had slipped down. The mechanic said that he had used the correct torque setting. He tried it again but the changer wasn't secure. Wheeled it into the workshop where unseen, I assume he tightened the bolt to a higher torque.
