Torque Wrenches

I had the same thought this morning so checked my local Halfords and they only have torque wrenchs
for cars. There must be something similar for bikes otherwise the manufacturers wouldn't specify
tensions, unless they do it for legal reasons. Maybe our bikes would last longer with the correct
tensions, nothing over-tightened, and nothing too loose?

Simon

MSeries said:

Who uses a torque wrench for their bikes ? What sort is it ? For years I haven't and had only few
problems, my cranks came loose once ! but I know I should do things in accordance with the manuals
especially on my best bike. Also I read on r.b.t that some one was getting a proper tool for the
Shimano self extracting crankset bolt cap, has anyone seen these for sale in the UK ? How would one
manage to tighten the cap to the correct torque (3-7 Nm) with what I imagine is simply a small pin
spanner ? I reckon it wouldn't really matter for this as it takes no stress in normal usage.

Whether or not you use a torque wrench may well depend on how good a "feel" you have when tightening
fasteners. If you are at all mechanically/practically minded then you should be able to manage
perfectly well without one. The diameter of the thread and materials involved should be your guide.
You'll need to go easier with aluminium than you would with steel for example.

By instinct, most people probably over tighten the size of fastener you find on your bike, but the
acceptable range in this kind of application is fairly forgiving.

The specific example you asked about, of a cap tightened to between 3-7 NM, will feel very light to
most people. It's barely more than a pinch with your wrist, you certainly wouldn't want to apply any
effort with a spanner or ratchet.

If you enjoy mech'ing your bike or want to know that you are being accurate then go ahead and buy a
torque wrench, but whatever you do buy a *proper* one. Don't go near the toy ones you'll find in
places like Argos, they are worse than useless and will likely be wildly inaccurate.

Good quality torque tools needn't be expensive, probably the best value option in the UK would be a
Norbar wrench. Excellent quality and very reliable. Something like the Norbar SL1 would be ideal for
your bike work, range of 8 - 54NM and only about £45 from a good tool dealer.

Using a torque wrench for a while will educate your wrist, as it were, so in the future you can be
more confident when working without one.
--

"Bob"

'The people have spoken, the [censored]'

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"Simonb" <[email hidden]> wrote in message
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Quoted message said:

I had the same thought this morning so checked my local Halfords and they only have torque wrenchs
for cars. There must be something similar for

bikes

Quoted message said:

otherwise the manufacturers wouldn't specify tensions, unless they do it

for

Quoted message said:

legal reasons.

Go to:

cromwell.co.uk1037.pdfOpen ↗

cromwell.co.ukbrowseOpen ↗

Like what Bob said, SL1 £46.22 mail order, credit cards accepted. (No, I don't work for Cromwell,
they are a local company but not just for local people).

Regards, Pete

On Sun, 15 Feb 2004 15:39:26 -0000, "MSeries"
<[email hidden]> wrote in message
<[email hidden]>:

Quoted message said:

Who uses a torque wrench for their bikes ? What sort is it ?

<url:http://www.sheldonbrown.com/tork-grip.html> of course!

Guy
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88% of helmet statistics are made up, 65% of them at the University of Washington.

MSeries said:

Maybe I should ask this in rec.bicycles.tech, they are keen on torque-ing there. Who uses a torque
wrench for their bikes ?

I do. I'm a bit of a torque obsessive (cars too)

My bike torque wrench is a 3/8" drive Sealey. Pretty cheap for a torque wrench, I bought it because
none of my car-sized torque wrenches went low enough to do bike bits. I use it for cranks mainly
(which is admittedly rare).

What sees more use on the bike is a torque screwdriver - 1/4" drive, but a screwdriver handle. Just
like a torque wrench, but for the extra low torques. These are essential if you're an aluminium bolt
lightweight fanatic, otherwise you'll shear things off on a regular basis. I find it's useful for
torquing up badly designed brake cantis like the infamous Onza HO that lock solid if mis-torqued,
and I mainly use it for putting the steel Allens back in the extra-soft alloy of my AMP girder fork.
Stripping a thread in that thing is a nightmare to repair.

--
Smert' spamionam

MSeries said:

Maybe I should ask this in rec.bicycles.tech, they are keen on torque-ing there. Who uses a torque
wrench for their bikes ? What sort is it ?

I only feel the need for one on cranks (square taper jobs). In fact I don't even own a TR, just
borrow a car mechanics type*. These cranks are more difficult to judge by feel than other fastenings
on a bike, partly because of the high torque, but mostly because you're not just simply doing up a
bolt but wedging something on. It does feel a bit different. A lot of people (including pro
mechanics) under-tighten cranks. Proper use of a torque wrench should prevent this, and also over-
tightening of course.

Having said that, I did strip the steerer clamp threads on the first ahead stem I used - didn't
realise how little torque they required.

* which I understand are not reliably accurate at low torque

~PB

MSeries posted ...

Quoted message said:

Maybe I should ask this in rec.bicycles.tech, they are keen on torque-ing there. Who uses a torque
wrench for their bikes ? What sort is it ? For years I haven't and had only few problems, my
cranks came loose once ! but I know I should do things in accordance with the manuals especially
on my best bike. Also I read on r.b.t that some one was getting a proper tool for the Shimano self
extracting crankset bolt cap, has anyone seen these for sale in the UK ? How would one manage to
tighten the cap to the correct torque (3-7 Nm) with what I imagine is simply a small pin spanner ?
I reckon it wouldn't really matter for this as it takes no stress in normal usage.

Opinions please.

Having been a 'Torque Control Engineer' for Desoutter (they make power tools and GR Electronic
Torque Control systems) for a while of my working life, and having worked on the Raleigh production
line, well, the Dyna-Tech part anyway, among many others, it was notable that the torque specs given
by most manufacturing companies are mainly for use in the factories using power tools and not
necessarily for home users to stick to. The torque characteristics of a hand and power turned bolt
are completely different and use different torque values.

Most Torque specs are also, nowadays, a sop to the ligitious society in USA and provide an extra
level of 'get-out' insurance for component failure.

IMHO a small 'home' torque wrench, used intermittently and probably without practice and under less
than ideal conditions, can do more harm than good. I never use a torque wrench nowadays, except when
re-building the bottom end of an engine, or other 'safety critical' component, like brake disc bolts
for instance. General bicycle maintenance is happily reliant upon 'feel' and the correct sizes of
spanner. One good reason for the differing lengths of spanners for differing sizes of nuts is the
amount of leverage (torque) that can be transmitted.

--
Paul

Pete Biggs said:

In fact I don't even own a TR, just borrow a car mechanics type*.

Quoted message said:

* which I understand are not reliably accurate at low torque

The accuracy on all torque wrenches drop away as you approach the edge of it's working range (either
upper or lower).
--

"Bob"

'The people have spoken, the [censored]'

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<[email hidden]> wrote in message
<[email hidden]>:

Quoted message said:

IMHO a small 'home' torque wrench, used intermittently and probably without practice and under less
than ideal conditions, can do more harm than good.

I think you are probably right - using Allen keys or spanners, which tend to be shorter the smaller
they are, means it's easy to feel the point at which the fastener is tight. Tightening a 6mm bolt
into aluminium with a monstrous great torque wrench you will never feel the thread go up and you
won't feel it strip either.

Guy
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In article <[email hidden]>, MSeries

Quoted message said:

Opinions please.

I have a torque wrench and I even have and have read the instructions
:-(

I have always been of the belief that if it feels right it probably will be. I have sheared a few
bolts during my working life - always when loosening ones which are rusted solid.

--
A T (Sandy) Morton on the Bicycle Island In the Global Village millport.netmillport.netOpen ↗

In article <[email hidden]>, Simonb

Quoted message said:

There must be something similar for bikes otherwise the manufacturers wouldn't specify tensions,
unless they do it for legal reasons.

A spanner of known length and a spring balance will work if you have enough time !

--
A T (Sandy) Morton on the Bicycle Island In the Global Village millport.netmillport.netOpen ↗

Quoted message said:

Opinions please.

A torque wrench should be unneccessary if you have a decent set of spanners. Spanners are designed
to administer an appropriate torque without inflicting pain on the user...stop and think about it,
small diameter bolts with small heads use small short spanners gripped by a few fingers and the
thumb, if you feel pain/discomfort when tightening a bolt then you are probably using too much force
this applies equally to the use of allen keys. There are very few instances where a high torque is
needed on a bike, the crank being one of them . Even then I reckon the lack of a torque wrench is a
'survivable' situation.

Adjustable spanners should be avoided on two counts...

a poor fit for the nuts/bolt heads easy to administer too much force on smaller sized bolts

I'd spend my money on something that gets more use.

Vernon in Leeds

MSeries said:

Maybe I should ask this in rec.bicycles.tech, they are keen on torque-ing there. Who uses a torque
wrench for their bikes ? What sort is it ? For years I haven't and had only few problems, my
cranks came loose once ! but I know I should do things in accordance with the manuals especially
on my best bike. Also I read on r.b.t that some one was getting a proper tool for the Shimano self
extracting crankset bolt cap, has anyone seen these for sale in the UK ? How would one manage to
tighten the cap to the correct torque (3-7 Nm) with what I imagine is simply a small pin spanner ?
I reckon it wouldn't really matter for this as it takes no stress in normal usage.

Opinions please.

Thanks to everyone who responded, pretty much what I expected to honest. Thanks.

John Hearns posted ...

Quoted message said:

Andy Dingley said:

What sees more use on the bike is a torque screwdriver - 1/4" drive, but a screwdriver handle.
Just like a torque wrench, but for the extra low torques.

Oooohhhh.... what an interesting thing. Reference please? Probably can't justify one to
myself though.

torqueleader.comscrewdrivers.htmOpen ↗

A tad expensive for home use though .. especially if you add on any sensing devices and other
'stuff' .. Maybe a good club purchase with a loan-out facility .. 😉

Others available from Cromwell Tools . cromwell.co.ukcromwell.co.ukOpen ↗

Look for part numbers

KEN-555-5010K KEN-555-5020K KEN-555-8050K KEN-555-8100K

All at about £120 ish ...

--
Paul

On Mon, 16 Feb 2004 18:11:28 +0000, John Hearns <[email hidden]>

Quoted message said:

Reference please? Probably can't justify one to myself though.

RS part 547-379 rswww.comrswww.comOpen ↗ (it's an unbookmarkable and generally ugly site)

NB - I paid a _lot_ less than that - more like a tenner on eBay