torque wrench for whole bike

Discuss light weight issues concerning road bikes & parts.
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F45
Posts: 898
Joined: Wed Jun 08, 2011 6:08 am

by F45

campagnolo321 wrote:
F45 wrote:Torque wrenches aren't accurate at all and are pretty much pointless if you know what you're doing.



Thats a great comment Mr. Armchair Engineer, please feel free to contact some of the well known torque wrench manufactures that produce said items for aerospace, motosport and other industries that are required to use torque wrenches and tell them just that !

Oh, and please post here the replys you get as I for one would love to hear the replys !


The inaccuracy isn't with the wrench, it's the highly variable friction in the bolt threads that will make your reading up to 30% off the intended clamping force. The clamping force is what we're going for, right, because of our fragile carbon parts? You can get a closer reading by using a good thread lubricant. But how many of you are doing this?

Say a bolt calls for 5 N-m. That is a little more than a pound force at one meter. So your 25cm wrench needs 5 lbs at the end of it. You need a special tool for that? You don't know what 5 lbs of force feels like? You can press on your digital scale to calibrate your hand if you're unsure. You can even hook your bike scale around your wrench and pull to the desired reading. I just don't see the point in keeping track of more tools than are necessary.

Flame away!

by Weenie


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BRM
Posts: 817
Joined: Sun Mar 16, 2014 3:43 pm

by BRM

NickD51 wrote:CDI is made by SnapOn so you know it is good.


Like to comment not on CDI but in the way you bring it.
Sub brand X is made by BIG BRAND so you know its good
Think in this case CDI delivers indeed A-class tools but . . .
Dont automatically think that all subbrands of A-class manufacturers are directly Always the same high standard.
There are many tool manufacturers with big names that have subbrands that deliver NOt the same standard.

eg Gedore has a subbrand Carolus which is simply not the same quality.
eg A brand like Stanley let manufacture their tools all over the world and quality is very divers through their total line.

Don't go out of a brand name only.

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BRM
Posts: 817
Joined: Sun Mar 16, 2014 3:43 pm

by BRM

F45 wrote:The inaccuracy isn't with the wrench, it's the highly variable friction in the bolt threads that will make your reading up to 30% off the intended clamping force. The clamping force is what we're going for, right, because of our fragile carbon parts? You can get a closer reading by using a good thread lubricant. But how many of you are doing this?

Say a bolt calls for 5 N-m. That is a little more than a pound force at one meter. So your 25cm wrench needs 5 lbs at the end of it. You need a special tool for that? You don't know what 5 lbs of force feels like? You can press on your digital scale to calibrate your hand if you're unsure. You can even hook your bike scale around your wrench and pull to the desired reading. I just don't see the point in keeping track of more tools than are necessary.

Flame away!


They did test among a number of professionals if they could guess by hand the right torque of a few things. The test showed many were way off. You may try yourself at home. Take a couple of bolts and torque them by hand. measure the outcome. Then go weightlifting, or carry some heavy boxes upstairs, whatever. And try again to torque by hand. Very likely you dont come close to earlier outcomes.

- Mosttime torque specs given are the MAXIMUM torque something can have and not the torque you should use.

- Very important is the LUBRICATION FACTOR.
A lubricated bolt has less resistance than non lubricated, and therefore with a lubricated bolt you should ALWAYS LOWER the torque.

Poulidor
Posts: 74
Joined: Sun Aug 23, 2015 3:50 am

by Poulidor

I'm no expert but I wouldn't use the same torque wrench to tighten the screws on a carbon fiber stem and the bolt on the Campagnolo bottom bracket. In my case, I have a German small Anschutz rifle torque wrench for the small stuff, and a Snap-On torque wrench for bottom brackets and so on. However, I recently bought from Amazon one of those inexpensive smaller wrenches with interchangeable tips for bicycles.

You really don't have to spend much for having what you need for a bicycle. Buy one of those readily available torque wrenches with variable tips for the small screws, and an arrow wrench from Sears for the bigger stuff. Whatever you do, always relieve the tension from the wrench before you put it away.

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Rick
Posts: 2035
Joined: Sat Aug 29, 2009 4:30 pm

by Rick

1: It is virtually impossible to have a single torque wrench that would cover the entire range of bicycle requirements. In fact, most torque wrench manufacturers will recommend not using the lowest and highest 10% of a tool's range. It is most accurate in the middle of the range.

2: I agree that there are a of of people who think they don't need a torque wrench, but studies have shown that they actually should be using a torque wrench. Can you get away without it?... Yeah. It's all fun and games right up until something snaps or comes loose. Having said that, though, I have had bolts snap even using a torque wrench (traced to defective bolts, not an inaccurate torque wrench).

A study done by having experienced mechanics tighten bolts by feel showed that they have a strong tendency to overtighten small bolts (less than ~6mm) while undertorquing large bolts (greater than ~6mm). So even "experienced mechanics" have a problem hitting correct torques by feel.

3. The lubrication condition does make a huge difference to the torque-vs-axial force relation. But that is why we should probably just follow manufacturers' recommendations for most installations. They would have (presumably) specified the correct torque for their own bolts. Most say to use lube, and loctite 242 (blue) is designed to have lubricative properties prior to cure. So I use a lot of that. My rule is to only use loctite on the bolts you want to stay tight.
For the ones you don't care if they come loose, you don't need to loctite them. :)


4. I got one of these also! Very convenient!
http://www.industrialsupplydenver.com/cditosc28nm1.html

AJS914
Posts: 2385
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

Things like stems and seatpost usually say "max" 5 or 6nm of torque. If you use a torque wrench where do you stop? At the max?

I've been wrenching on bikes for 40 years and never used a torque wrench until recently. With carbon bars, seatposts, etc. I was getting worried that I was getting it wrong. So, I bought a 5nm Ritchey Torque Key. What I found was that I was typically under 5nm for things like stems. It seems like too much torque to me.

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BRM
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Joined: Sun Mar 16, 2014 3:43 pm

by BRM

AJS914 wrote:Things like stems and seatpost usually say "max" 5 or 6nm of torque. If you use a torque wrench where do you stop? At the max?

No especially when you lubricate the bolt you need to stay at the safe side.
Because the use of lubricant makes it easier to turn the bolt, less torque is going to be needed.
In your example for 5Nm max, your torque setting needs to be something like 3-3,5 Nm

The cycling industry is a mediocre industry, and so are the torque instructions.
The right torque is not just a fixed number. Is the torque spec based on a dry bolt or lubricated? And based on which lubrication and which bolt material exactly?
The right torque should be calculated with as input things like used material and used lubrication.


Google on: torque and lubrication or torque lubrication effects, to find confirmation for my words.

AJS914
Posts: 2385
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

I don't need to google. I'm familiar with this because of having done a lot of wrenching on cars.

I'm just glad that the Ritchey Torque Key confirmed that I was doing it right all along.

superdx
Posts: 516
Joined: Sun Jun 29, 2014 1:27 pm

by superdx

http://www.parktool.com/product/adjusta ... ue%20Tools

This one gets everything done on my bike except a Fizik R1 seatpost which needs 8Nm of torque, but I just tighten to 6Nm and then push a little more with a normal wrench and good enough. And of course the cassette which needs almost 40Nm torque to tighten.

NealH
Posts: 496
Joined: Sat May 12, 2007 3:40 am
Location: Triange, NC

by NealH

AJS914 wrote:Things like stems and seatpost usually say "max" 5 or 6nm of torque. If you use a torque wrench where do you stop? At the max?

I've been wrenching on bikes for 40 years and never used a torque wrench until recently. With carbon bars, seatposts, etc. I was getting worried that I was getting it wrong. So, I bought a 5nm Ritchey Torque Key. What I found was that I was typically under 5nm for things like stems. It seems like too much torque to me.


The margin or overall tolerance is not all that small really. The manufactures typically disregard the friction component of torquing so, even if you lightly lube the threads you will still not over torque it. Just torque to the max figure and you'll be fine.

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BRM
Posts: 817
Joined: Sun Mar 16, 2014 3:43 pm

by BRM

NealH wrote:
AJS914 wrote:Things like stems and seatpost usually say "max" 5 or 6nm of torque. If you use a torque wrench where do you stop? At the max?

I've been wrenching on bikes for 40 years and never used a torque wrench until recently. With carbon bars, seatposts, etc. I was getting worried that I was getting it wrong. So, I bought a 5nm Ritchey Torque Key. What I found was that I was typically under 5nm for things like stems. It seems like too much torque to me.


The margin or overall tolerance is not all that small really. The manufactures typically disregard the friction component of torquing so, even if you lightly lube the threads you will still not over torque it. Just torque to the max figure and you'll be fine.


Very wrong information.
First Lubrication factor really matters. It can dramatically lower the friction with dramaticaly different results.

Here is just a sample>
Image

Other sample of A Dutch guy that did a test>>
Image
2 bolts where same 5 Nm is used. First picture is dry, second is lubricated
If you want the non lubricated as far squeezed as in second pic you need 14 NM

Here we see that the Lubrication factor is of high importance.
(and now you also will understand that a torquewrench is in fact only useful when you know also the lube factor and properties of the bolt, like threads and material)



When instructions speak of particular torque setting you use that torque.
However when there is just a max torque mentioned then its not that you should use max setting. Max is the max what the bolt can have not what you should use as setting. It's not a torque setting specification, its a bolt specification.

Poulidor
Posts: 74
Joined: Sun Aug 23, 2015 3:50 am

by Poulidor

Now I'm really confused. I guess I'll use blue Loctite and tighten to a bit less than recommended. I should have never read this thread :-)

highdraw
Posts: 489
Joined: Thu Sep 04, 2014 12:23 pm

by highdraw

BRM wrote:
NealH wrote:
AJS914 wrote:Things like stems and seatpost usually say "max" 5 or 6nm of torque. If you use a torque wrench where do you stop? At the max?

I've been wrenching on bikes for 40 years and never used a torque wrench until recently. With carbon bars, seatposts, etc. I was getting worried that I was getting it wrong. So, I bought a 5nm Ritchey Torque Key. What I found was that I was typically under 5nm for things like stems. It seems like too much torque to me.


The margin or overall tolerance is not all that small really. The manufactures typically disregard the friction component of torquing so, even if you lightly lube the threads you will still not over torque it. Just torque to the max figure and you'll be fine.


Very wrong information.
First Lubrication factor really matters. It can dramatically lower the friction with dramaticaly different results.

Here is just a sample>
Image

Other sample of A Dutch guy that did a test>>
Image
2 bolts where same 5 Nm is used. First picture is dry, second is lubricated
If you want the non lubricated as far squeezed as in second pic you need 14 NM

Here we see that the Lubrication factor is of high importance.
(and now you also will understand that a torquewrench is in fact only useful when you know also the lube factor and properties of the bolt, like threads and material)



When instructions speak of particular torque setting you use that torque.
However when there is just a max torque mentioned then its not that you should use max setting. Max is the max what the bolt can have not what you should use as setting. It's not a torque setting specification, its a bolt specification.

Above is true and adds a huge level of complexity when it comes to bolt torque. If you guys want your mind boggled, pretty much any car forum on the web debates road wheel lug nut torque with and without antiseize on the threads and there is never any consensus. :) Suffice to say that clamping torque goes way up when lubrication is applied to the thread at the same torque as shown in the pic..and of course clamping force is a concern and carbon is sensitive to it. In summary, retention in the presence of vibration which is the case on a road bike riding over less than pristine roads...can be reduced with thread lubrication and clamping force goes way up for the same torque applied when threads are lubricated. So adding lubrication to threads in the context of torque and clamping force is a slippery slope when it comes to clamping force and torque retention...forgive the pun relative to thread pitch. ;)..finer pitch threads retain torque better proportional to the sine of the thread pitch.

As to the OP's question, like many of you guys here...I don't see that one size fits all when it comes to torque wrenches either. My wrenches of choice are click type...3/8" drive small one for the little fasteners on the bike...I primarily use a torque wrench for seat post clamp which is pretty critical...don't want a cracked frame but can live with a cracked stem ;)...and I use one for bottom brackets as a rule....and cassette lockring. For high torque applications on bikes mentioned which are few, I want a long lever torque wrench and not a little one to more easily achieve desired torque target.

Anyway OP...my thoughts. Again, I don't use a torque wrench on everything but I do find them worthwhile for certain applications when I want to hit a torque spec precisely...again actual clamping is affected by thread lubrication and I tend to use grease on the threads of most fasteners on a bike...so clamping force on my bikes is high relative to industry standard torque targets for bike components...like 55 in-lbs is what I use on a seat tube clamp...with a bit a grease on the locking collar bolt thread.

Jmdesignz2
Posts: 287
Joined: Tue Jan 13, 2015 2:27 am

by Jmdesignz2

Yes - I believe you can't blindly use torque wrenches unless the mfg of the parts gave very specific instructions. Also, good idea to use 90% of the min torque or less if it's on a part that clamps another. For example, seat binder bolt, front der bolt, stem steerer bolt. Test tightness/slip.

IMHO Never use max right away as you could easily exceed max torque and then you are into the danger zone. I would throw away any preset "torque" keys and re-educate any mechanics who blindly torque every part to the max without using some feel.

I would also agree with most here- to answer the OP's question: you need a small 1/4 inch or 1/8 inch torque wrench for the lower torque ranges and a large 1/2 inch one for the higher ranges.

Harbor freight torque wrenches have been shown to be as accurate as much higher priced brands

http://www.hotrod.com/how-to/additional ... h-testing/

here
http://toolmonger.com/2007/03/28/hot-or ... -wrenches/
some calibration techs say:

"I run the cal department for an automotive testing company and I calibrate about 100 torque wrenches per year. All types from cheap HF clickers to very expensive Snap-On digital readouts. The build quality of the HF wrenches is horrible but in my experience they are in spec when new but “go south” with age & use. Most of the technicians here own better brands because the outcome of a customer’s test can depend on the bolts being tightened to a recommended torque. I’m writing this today because I’m searching the web looking for a clue how to open a HF wrench to adjust it, without damaging it in the attempt. There might be a good reason a couple older posts mentioned they couldn’t get a HF wrench adjusted–it might not be possible. Consider it a disposable tool and toss it when it checks bad.

A tip: ALL click-type torque wrenches should be “exercised” before use. This means dial it up to the maximum setting & torque a fastener that’s tighter than the wrench max (for example exercise your 50 ft-lb wrench on a lug nut). Inside a clicker there is only a spring pressing a hardened block between 2 anvils. The block will roll when the spring setting is exceeded. This tilts the head-end anvil and it bangs into the wrench tube. This is the “release” you feel and the “click” you hear and feel. Any wrench that doesn’t get used often can get a little sticky and is the reason the manufacturer recommends exercising it first. The spring is the reason you reset your wrench to minimum after use so it doesn’t weaken over time."

and this
http://www.motorcycleforum.com/showthread.php?t=119543

highdraw
Posts: 489
Joined: Thu Sep 04, 2014 12:23 pm

by highdraw

Jmdesignz2...question please.

You wrote:
A tip: ALL click-type torque wrenches should be “exercised” before use. This means dial it up to the maximum setting & torque a fastener that’s tighter than the wrench max (for example exercise your 50 ft-lb wrench on a lug nut). Inside a clicker there is only a spring pressing a hardened block between 2 anvils. The block will roll when the spring setting is exceeded. This tilts the head-end anvil and it bangs into the wrench tube. This is the “release” you feel and the “click” you hear and feel. Any wrench that doesn’t get used often can get a little sticky and is the reason the manufacturer recommends exercising it first. The spring is the reason you reset your wrench to minimum after use so it doesn’t weaken over time."
_________

Seems like good advice and sounds like torque wrenches are your expertise.
Can you tell us the average torque difference in percent between not performing the max torque free up of a click style wrench versus performing it? What is the torque disparity over the range of torques you have tested? Is the delta in torque with and without procedure...is it greater or less with a higher torque? I would think the delta in torque with and without method aka accuracy would improve at higher torque overcoming internal wrench friction but wanted to hear if you have performed this study and what your findings are.
Thanks

by Weenie


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