Author Topic: Torque wrench  (Read 258 times)

0 Members and 1 Guest are viewing this topic.

Phil C

  • Star
  • *
  • Posts: 23
    • View Profile
Torque wrench
« on: 23 August, 2017, 17:18:21 »
I hope in the coming months to get a first classic (maybe a Starfire or B40 or such like). I am a beginner at this (it's a retirement thing) and know pretty much nothing. Obviously I'll need to find some suitable tools, eg BSW combination spanners or whatever is needed for the particular bike, which I guess I can do online, but I was wondering: will I need a torque wrench?  Phil.

om15

  • Star
  • *
  • Posts: 23
    • View Profile
Re: Torque wrench
« Reply #1 on: 23 August, 2017, 19:31:20 »
Best advice I can give is buy the best quality tools you can afford, less chance of damage to the bike and will be easier to use, - spanners and sockets will be slender and give better access.
If you are unfamiliar with using tools then a torque wrench is advisable rather than using your own "feel", not too expensive and will help to prevent overtightening (stripped threads) and under tightening (leaks).
I have a set of old BSF spanners (used on RR Merlins), but still find odd threads on my C15, you might find that a set of metric and BSF/Whitworth spanners will get you started.

Phil C

  • Star
  • *
  • Posts: 23
    • View Profile
Re: Torque wrench
« Reply #2 on: 23 August, 2017, 19:48:17 »
Thanks om15. I have, years ago, worked in engineering (turning, milling, sheet metalwork, welding, etc) but have no experience of motorbike maintenance. From what you say, it appears a torque wrench is desirable but not essential?  Phil.

JulianS

  • Empire Star
  • *****
  • Posts: 488
  • A10
    • View Profile
Re: Torque wrench
« Reply #3 on: 23 August, 2017, 20:01:10 »
If you go for the Starfire there are a number of torque figures quoted for it.

If you go for a Starfire you will also need some AF spanners as they stared to change to Unified threads around that time.

GBonduel

  • Star
  • *
  • Posts: 8
    • View Profile
Re: Torque wrench
« Reply #4 on: 23 August, 2017, 22:02:10 »
There are few more satisfying things than feeling a torque wrench click; that said unless you completely disassemble your engine there few fasteners that will actually require it.
$25-30 will get you a decent enough torque wrench, there´s no hurry so you can wait around for deals.

STAR TWIN

  • Royal Star
  • ***
  • Posts: 124
  • A7 A10 B31 WDB40
    • View Profile
    • Strange Sheep
Re: Torque wrench
« Reply #5 on: 23 August, 2017, 22:08:31 »
I do have a torque wrench but very rarely use it. If you have an engineering background, you should be more than capable of avoiding under/over torquing nuts etc. It's just the really essential nuts and bolts - con rod big ends for instance - that can benefit from the use of a torque wrench. And as you will know, you have to allow for clean thread vs lubricated thread and so on.
A good set of Whitworth spanners and 3/8" drive sockets is a good start.

Phil C

  • Star
  • *
  • Posts: 23
    • View Profile
Re: Torque wrench
« Reply #6 on: 23 August, 2017, 22:33:49 »
This is all very useful and interesting - thanks everyone. As I say, I've no experience of motorbike maintenance, although years ago I had quite a lot of experience of screw threads, having made lots of them by various means,  (tap, die, lathe tool, etc), but I'm not sure I understand what you mean, Star Twin, when you say "...you have to allow for clean thread vs lubricated thread and so on." Could you enlighten me please?  Phil.

GBonduel

  • Star
  • *
  • Posts: 8
    • View Profile
Re: Torque wrench
« Reply #7 on: 23 August, 2017, 23:56:24 »
Definitely invest in good Whitworth sets and spanners first.

When torqueing down a bolt, either with a torque wrench or by feel, if the thread is lubricated by any means (such as anti-seize) the force needed will be much less than for a dry thread.

Reasoning behind this is that the friction in a dry thread will resist movement and so for the same "pulling" force on the bolt a much higher force is needed. If you use the dry number on a lubricated thread you run the risk of snapping the bolt or damaging components.

STAR TWIN

  • Royal Star
  • ***
  • Posts: 124
  • A7 A10 B31 WDB40
    • View Profile
    • Strange Sheep
Re: Torque wrench
« Reply #8 on: 24 August, 2017, 06:15:35 »
Succinctly put. For big end bolts, accurate measure of bolt stretch is more accurate than torque figures. You just need the appropriate micrometer and the stretch figures - not always available!

Phil C

  • Star
  • *
  • Posts: 23
    • View Profile
Re: Torque wrench
« Reply #9 on: 24 August, 2017, 08:19:50 »
Thanks.  I'm guessing that, unless specified otherwise in the manual or service sheets, we would normally a) assemble dry, and b) assume torque settings given are for dry?  Phil.

chrisgoodwin

  • Star
  • *
  • Posts: 30
    • View Profile
Re: Torque wrench
« Reply #10 on: 24 August, 2017, 12:02:19 »
A decent set of spanners is essential and a good metric socket set has got me out of trouble on more than one occasion.
But to throw my two penneth in, have you considered a B31 or 33? The pre unit singles are simple motors and easy to work on, spares are plentiful and the machines themselves are at the more affordable end of the spectrum - Or am I just biased!

STAR TWIN

  • Royal Star
  • ***
  • Posts: 124
  • A7 A10 B31 WDB40
    • View Profile
    • Strange Sheep
Re: Torque wrench
« Reply #11 on: 24 August, 2017, 13:47:31 »
It's fair to assume torque figures are for dry threads. B31 or unit single? These days it's an age thing... More and more people are looking for lighter bikes like C15s and cubs (both Triumph and Honda). Hopefully I'll be riding my heavyweights for a good while longer yet!

GBonduel

  • Star
  • *
  • Posts: 8
    • View Profile
Re: Torque wrench
« Reply #12 on: 24 August, 2017, 21:50:23 »
Torque settings are always given dry, unless specified.

As a B31 owner they are indeed relatively easy to work on (except for the carb if pre-monobloc) and most parts are easy to find.

Don't know if it's the same in other BSA's but I ended up not using my torque wrench on the head studs but instead hooked a small scale to the spanner to approximate the torque.

Phil C

  • Star
  • *
  • Posts: 23
    • View Profile
Re: Torque wrench
« Reply #13 on: 25 August, 2017, 11:23:19 »
Many thanks everyone.  Phil.