Torque wrench

[prando]

After 2/3 years riding a carrera virtuosa, I updated 6 months ago to a second hand 2013 defy 1. A number of the nuts are marked with a torque reference (e.g handlebar stem and adjustable expansion 5nm and 10nm)

Should I invest in a torque wrench ? In the absence of other marked torque references, do I need worry about tightening ? I have to date just 'tightened' with a multitool.

Where would I find the information as to what torque ?

Any recommendations as to purchase ? I have read other threads about Aldi, but am thinking of eBay or Screwfix.

[Brucey]

get a good 3/8 drive torque wrench + bits for versatility, or preset tools for simplicity (in good bike shops).

A Sealey 3/8" drive model I have seen has a very good low torque capacity which is what you need for small bolts on bikes.

You can find the torque settings in the owner's manual in most cases. The Park tools website contains a page with more generic information of bicycle torque settings.

cheers

[Valbrona]

It perhaps depends how keen you are on kitting out a home workshop, as opposed to practical usage.

I use a digital 3/8" torque wrench for the bigger jobs at around the 50Nm mark, like BB cups, crank bolt(s) and cassette lockring. And it looks great on my tool board.

I have had a lot of experience of working on bikes so reckon I have a pretty good feel at the lower end of the torque range, at around the 5-10Nm mark. If you err on the side of caution at lower torque specs that usually rules out the possibility of damaging components, but at risk of things loosening up. So ride with a little caution after doing any work ...

I have created a spreadsheet for each of my bikes listing recommended torque settings. But I don't get out much.

And if you use carbon components ... get some carbon paste.

[Valbrona]

And you, of course, need a 1/4" torque wrench for the small uns.

[Brucey]

And you, of course, need a 1/4" torque wrench for the small uns.

if you choose the right 3/8" drive torque wrench, you can get them that go down to 2 or 3 Nm. Hence my suggestion of looking at Sealey models earlier. There are others, too, maybe the BBB (?) one is good also?

cheers

[Valbrona]

Yeah, you can get a 3/8 that does right from the lowest torques to the highest you might typically find on bikes these days - 50Nm or so. But they are typically quite cumbersome and have to be used with an adapter for 1/4 bits. I would always recommend both a 1/4 and a 3/8.

The OP might be interested in the little pre-set ones from Ritchey (Torquey/or similar?) and others, which are typically suitable for 5Nm applications, like stem bolts.

[The Mechanic]

I recently purchased my first carbon framed bike. I also bought a torque wrench so that I didn't break anything. However, I find that the correct torque setting for things like the seat post clamp are much tighter than I would normally do by feel. I thought at first that the wrench was not working but it appears to be doing so (I have not calibrated though). I found it a bit scary at first as the bolt was getting tighter and tighter and I thought is was going to strip the threads but then the torque wrench clicked. Sigh of relief.

PS I have not had any issues with bolts coming loose in the past.

[Revolution]

A word of warning regarding torgue wrenches - Very few of them work on left hand threads. Although the ratchet enables clockwise or anti-clockwise operation, the torque indication (a click from the wrench) does not happen on left hand threads - I almost found this to my cost when tightening a bottom bracket.
I have a Sealey 3/8" one which is very accurate but only down to 6nm - definitely worth the investment.

[Brucey]

Yeah, you can get a 3/8 that does right from the lowest torques to the highest you might typically find on bikes these days - 50Nm or so. But they are typically quite cumbersome and have to be used with an adapter for 1/4 bits. I would always recommend both a 1/4 and a 3/8.

I have a very nice 1/4" torque wrench and I use it where necessary. But I wouldn't go out and buy one for occasional use if a 3/8" one would do the job.

My suggestion for bits is that for 6mm hex and below, you get a 1/4" hexagon drive adaptor to fit your torque wrench and matching loose 1/4" hex drive bits. The bits are inexpensive, can be bought easily and replaced if they are lost or get worn etc. You can get adaptors that go 1/4" square to 1/4" hex and/or 3/8" square to 1/4" hex, so you can use the same bits with either drive size quite easily.

For 8mm and larger bits, you can use an 8mm hex drive similarly, or fixed bits mounted in socket ends. 8mm and up, a 3/8" drive makes sense torque-wise so I'd get those.

Park tools sell a nice torque wrench and bit/socket set. You can buy similar stuff elsewhere for a fair bit less than that if you shop around; you probably won't need all the sizes either. Although they are not cheap by any means you can buy individual 3/8" drive mounted bits in Halfords; if you buy their 'professional' range they have a lifetime warranty on them. If you only need a few sizes this might be the best way of getting what you want.

cheers

[prando]

Thanks for the excellent advice one and all. I am now looking at various deals. I have a 'pre-set' 5 nm wrench but that seems to be a one off. An adjustable wrench seems the right option as suggested, albeit I am only aware of 2 specific torque setting requirements( both on handlebars )
How often do most of you check the various tightenings, and do you check all the 'major' nuts ?

[Brucey]

it varies from bike to bike but the bolts that give the most cause for concern are

-stem to handlebar clamp bolts
- stem to steerer clamp bolts
-crank and top cap preload adjusters (*)
- LH crank bolts on HT-II cranks
- seat binder bolts
-any clamps in or onto carbon parts

it is very easy to overtighten any of these bolts.

Note that (*) these have a very low torque setting; you may not find a 3/8" drive wrench that goes this low. Commonly these bolts are set using 'first absence of play' rather than torque as the arbiter.

In most cases if you are running very lightweight kit I'd suggest inspection once every six months or so anyway. The bolts should be retorqued on reassembly. If you check with the torque wrench between times this is usually OK, but a tiny minority of joints will ease off in service (without the fastener backing out) and repeated retorquing may eventually cause damage in these cases.

cheers

[prando]

Thanks Brucey buddy. Great information. I've a feeling I've over tightened in some cases. Will recheck once I have made my purchase ! I was quite surprised at how expensive these wrenches are...or can be.

[mattsccm]

There are several 5nm ones out there for under 20 quid. Fine for seat posts, stems etc. Big stuff isn't as fussy as far as I am concerned.

[MikeF]

I bought this Sealey torque wrench http://www.amazon.co.uk/gp/product/B000RO1ZCG/ref=oh_details_o04_s00_i00?ie=UTF8&psc=1 and these bits http://www.amazon.co.uk/gp/product/B0012MEK0Q/ref=oh_details_o04_s00_i01?ie=UTF8&psc=1
I think I paid around £34 for them, but the price seems a bit higher now. It's fine for bike use. I already have adaptor sockets as well as larger Norbar torque wrenches.
As with any torque wrench always slacken it off completely when you've finished using it.

On the other hand if you have something really tight to undo, eg screw on freewheel then this Sealy bar http://www.amazon.co.uk/gp/product/B000O619PA/ref=oh_details_o05_s00_i01?ie=UTF8&psc=1 is also very useful, and saves using a piece of pipe on a T bar!