# Do I need a torque wrench?



## Azaex (Jul 24, 2015)

Relatively new rider here, I picked up a 06' Trek X01 bike off someone lately that had a carbon stem and seatpost fitted (both Easton EC70, the frame is aluminum though). I don't own a torque wrench now, but is it something I should own? Googling around has shown me that some people get along by not going beyond what they "feel" is too tight, and other people swear by the wrench. I've never personally compared myself to a torque wrench before so I don't know if I've actually gone beyond, say, 5Nm; right now I tighten about to the point where I can barely use my index finger to push down ~5cm from the wrench.

If I were to get a torque wrench, is there loss of calibration ever an issue with cheaper click type wrenches? If anything I don't want to spend $100 on a decent wrench that won't see much use, maybe a beam type is better suited to home use?


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## Srode (Aug 19, 2012)

A beam style is a good choice for bikes if it's one that reads in the range you are working. Park Tools makes one that is reasonably priced, like $40 that reads in the range you will want. I use a clicker but only because I already had one for auto work. 

They are more important if you have a carbon fiber bike. If you are going to change many components on your bike you should definitely have one (cassette for sure needs one IMHO). If you are just adjusting saddle height you can probably get by with a torque key instead.


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## n2deep (Mar 23, 2014)

IMHO, the design of the beam type wrench has several distinct advantages for the home owner over the click type wrenches; including simplicity of design (less parts to malfunction), repeatability and little or no maintenance. Click types are also great tools but I would like to have a skidmore type of device to sporadically check the wrench. Although you can check the accuracy of both types with a known weight and a little string.


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## MMsRepBike (Apr 1, 2014)

Are you going to do any work on your own bike?

If the answer is yes, then you need a torque wrench. And you also need to know how to use it. You need to understand how greasing bolts effect their torque value and how using carbon assembly paste will do the same. You need to pay very close attention to the manufacturer's specs and whether or not they're dry specs.

You will need two torque wrenches if you plan to do a lot of work on your bike. One is needed for the bottom bracket/cassette/pedals, etc that does high torque around 40 newton meters. The second one will be a small one that doesn't go above 15 newton meters and that'll be for all of the bolts and such on the bike.


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## PJ352 (Dec 5, 2007)

I've done my own wrenching for the last 25 years... 7 of which on CF. Never used a torque wrench and never broke a bolt or suffered a mechanical. So, if you're as careful as you say you are, IMO you don't *need* a torque wrench.

That said, if you do decide to get one, as another member mentioned, it's important to learn how to use it (like any other tool), because you can still over/ under torque bolts using them.


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## rm -rf (Feb 27, 2006)

I use a torque wrench. If I was working in a bike shop, I'd get the feel for how tight bolts should be, but I don't have enough experience to know. I don't worry about calibration. I tend to use less torque on stems and seatposts than the max listed number. ( But some things like bottom brackets are set to their recommended numbers)

I got some Tacx carbon assembly paste some years ago. It's a gel with plastic grit in it. A tube will last you 10 years.

The stuff really works. I use it on aluminum seatposts, on aluminum handlebars, and on carbon bits, of course. The seatpost and bars stay in place reliably with less force required on the bolts.


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## 9W9W (Apr 5, 2012)

I just picked up a BMC SLR01 the other day. I looked at the seatube clamp which said do not exceed 3nm and knew this was going to be tough going. Also, the seatpost clamp is a two bolt carbon affair which requires repeat trial and error to get just right. I can't even use my Ritchey click tools which are set to 5nm. I'm considering getting a wrench as I have some work to do on the bike and will be moving my position over from the LOOK myself. I used to ham fist the LOOK frame until the tool clicked and then some, somehow I feel that just looking at BMC's .022" walls may cause them to crack. 

I noticed some guys recommend the beam type, but those are good only for much higher torques (think casette swap). I did see a Spin Doctor or Venzo bicycle gauge dial-in type wrenches on Amazon for $50. I'm wondering how much weight to give the few reviews which claim the tools are crap. 

http://www.amazon.com/VENZO-Bicycle...ower-hand-tools&ie=UTF8&qid=1438719662&sr=1-5

I'm starting to think since you had to listen for the click and use steady linear pressure ramp up, at least some of the negative reviews were user error.


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## tlg (May 11, 2011)

9W9W said:


> I noticed some guys recommend the beam type, but those are good only for much higher torques (think casette swap).


They come in different sizes. A 1/4" drive beam will have a 7nm max torque.


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## headloss (Mar 3, 2013)

Best way to train your hand is with a torque wrench. You can get them cheap at Harbor Freight (they are good enough for bike mechanics). I agree about the beam type if you can find one, but clicking type is fine (but not as idiot proof).


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## froze (Sep 15, 2002)

Automotive torque wrenches usually measure in foot pounds and not inch pounds so you have to convert to make sure it fits the range you need. Torque wrenches for bikes must read from 26 to 132 inch pounds for most bike stuff, however for things like the bottom bracket, the lock ring on a cassette the range needs to be from where the lower one leaves off to 530 inch pounds. Harbor Freight has added a new one that has a range of 20 to 200 (1/4th drive) but their next one has a small gap from the smaller one and it starts at 240 and goes to 960 (20 to 80 foot pounds)(3/8ths drive). 

Harbor Freight tools are just as good as anywhere else these days except for the ones sold to professional mechanics in large vans that run from shop to shop, but they will get the job done for cheap.

I actually think the clicking type is more idiot proof than the beam type, you just set the adjustable handle to whatever rating you want and go, when it clicks it's done. Beam type while being a tad more accurate has the problem that some people will shake while using it and the beam can swing and be way off compared to a clicker; also if you accidently drop a beam type you take a high risk of bending the beam then you're screwed. 

Remember to always set a clicker or beam type to zero when not in use.


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## 9W9W (Apr 5, 2012)

tlg said:


> They come in different sizes. A 1/4" drive beam will have a 7nm max torque.


Tanks for this heads up! I learned something. Will definitely pick up a small-scale beam like this over click type w/o calibration.


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## Sundog (Sep 25, 2013)

If I recall correctly - back to my days wrenching on US Navy Nuclear Power Plants - the canoe club restricted torque wrench use such that the final torque value had to fall between 1/4 and 7/8 of the scale of the wrench. The was considered the useful range. 

All the wrenches on the boat were calibrated once every six months or once per year - I forget which. Most were the dial type. Beam types were not authorized (considered less accurate mainly due to the user errors in reading off center when bolting up a feed pump casing while sitting upside down in a bilge). Micrometer (click type) were probably too expensive or sensitive to abuse.

Lesson learned: if you are wrenching on your bike in a confined space or a high radiation area - get the clicky kind.


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## redcon1 (Jul 22, 2008)

In the US Army nuclear surety program we always used Micrometer-type torques wrenches calibrated every 6 months by depot-level maintenance. Agree with Sundog about the torques value restrictions between 1/4 and 7/8 of the scale. For a carbon bicycle I use 3 micrometer-type wrenches with overlapping ranges. I use a Calculator app on my iPhone to convert the NM to inch- or foot-lbs.

And for those wondering what business the Army has in nuclear surety, back in the day I served in a nuke-capable 155mm Artillery Battalion. 203mm (8-inch) Arty also had nukes. Not a sad day for us when we turned all the weapons and equipment in due to the SALTII disarmament.


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## giosblue (Aug 2, 2009)

If you have to ask the question, then you probably do. Don't use one myself though.


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## ParadigmDawg (Aug 2, 2012)

n2deep said:


> Although you can check the accuracy of both types with a known weight and a little string.


|- Extender (length = E) -|- Torque Wrench (length = W) -| O-----------------------O---------------------------======= handle socket

Reference https://www.physicsforums.com/threads/torque-wrench-tool-calculation.432352/


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## Ventruck (Mar 9, 2009)

PJ352 said:


> I've done my own wrenching for the last 25 years... 7 of which on CF. Never used a torque wrench and never broke a bolt or suffered a mechanical. So, if you're as careful as you say you are, IMO you don't *need* a torque wrench.
> 
> That said, if you do decide to get one, as another member mentioned, it's important to learn how to use it (like any other tool), because you can still over/ under torque bolts using them.


funny how the thread bumps right when I have a relevant issue. Your post really sums it up perfectly.

Same story for me: going off perception has been just fine for me, even better when my recent bike which was bought from an LBS had the bolts tightened to the same extent I'd apply.

A friend insisted I use a torque wrench, and we went through the bolts on my bike recently. I found out my seatpost clamp was actually stripped afterwards. This was a complete first for me, and I'm surprised the seatpost or frame didn't crack. Maybe it was a faulty clamp, but maybe the tool was off-calibration, and he went for the max — not necessarily *recommended* — 5Nm torque; but I do I know the feel of that torque was way beyond that of the LBS and myself. No hard feelings ($25 isn't a reason to hate anyone), and it's not like the tool is inherently wrong, but it CAN go wrong if you don't use it right.

So that being said, I don't see major advantage for a torque wrench. You'd end up trusting a "click" instead of your perception that comes with experience, and I'd think that's actually worse. On top of that, the recommended measures for carbon parts are fuzzy since layups and grade differ. I know some people would find that carbon paste actually yields a lower demand of torque to work reliably...so is that click or meter really all that helpful?

I'd think a torque wrench would only start making sense for automotive or industrial applications where stresses are larger and torque demands are higher.


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## tednugent (Apr 26, 2010)

Torque wrenches are good if you don't know the "feel" of your tools.

For mechanics, since they are constantly using their tools, the same tools, over and over again, they develop the feel and known when to stop. They can always verify the torque by breaking the torque with a beam torque wrench, then re-torque it (unless you're using stretch bolts, but I don't know of an application of stretch bolts for cycling).

Anti-seize, Carbon-paste, and grease, all have a lubricant base. If a torque requirement is based on dry threads, using those compounds will require you to drop the torque by approximately 20%. For example, that 5 Nm, now becomes 4 Nm.


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## goodboyr (Apr 19, 2006)

I know you said "mechanics" buy I don't think you are referring to those monkeys in many lbs. I would not trust them to have a "feel" of anything. So from a practical point of view, a torque device is a good practice for working on bikes.....period.


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