# What Torque values for 3T Carbon handlebars?



## jasonwells4 (Aug 7, 2006)

I just got my 3T Ergonova LTD handlebars from ProBikeKit(in 1 week!). They don't seem to come with any installation instructions, and I couldn't find any product manual on the 3T website.

What should I be torquing the stem-handlebar clamp to? And how about the shifters?

I just have a 2 bolt Bontrager stem right now, but I'll probably get a 4 bolt unit soon.

Thanks.


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## wim (Feb 28, 2005)

jasonwells4 said:


> I just got my 3T Ergonova LTD handlebars from ProBikeKit(in 1 week!). They don't seem to come with any installation instructions, and I couldn't find any product manual on the 3T website.
> 
> What should I be torquing the stem-handlebar clamp to? And how about the shifters?
> 
> ...


Torque is rotational force as exerted on a bolt or screw. Since the handlebar doesn't have any bolts or screws, the manufacturer can't give you any values. You need to use the values given by the stem- and shifter manufacturers, or use a general guideline like the one on the Park Tool website.


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## C-40 (Feb 4, 2004)

*thoughts...*

A good carbon bar should not have critical torque limitations. Most 4-bolt face plates recommend 5Nm of torque. I've never put a torque wrench to the band clamp bolts, but Shimano lists a torque of 6-8Nm in their instructions. 

I still recommend to those who want to learn bike mechanics to learn what those small torques feel like, by hand, and not become so dependent on a torque wrench. I've never put a torque wrench on any M5 or M6 bolt.


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## jasonwells4 (Aug 7, 2006)

Thanks, I'm just being cautious with clamping forces on the CF. I always use a torque wrench on the car too. Especially when working on a cylinder head.


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## wim (Feb 28, 2005)

jasonwells4 said:


> Especially when working on a cylinder head.


That brings back some memories—I remember those neat sequence diagrams and the fact (this was long ago) that you had to re-torque after the intial engine run.


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## been200mph (May 28, 2004)

I still retorque head stud nuts on my race motors after initial run-in/dyno pulls.


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## wim (Feb 28, 2005)

been200mph said:


> I _still retorque head stud nuts on my race motors after initial run-in/dyno pulls_.
> 
> Beautiful,wow! What's with the optional connection—different response to the pedal?


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## been200mph (May 28, 2004)

wim said:


> been200mph said:
> 
> 
> > I _still retorque head stud nuts on my race motors after initial run-in/dyno pulls_.
> ...


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## wim (Feb 28, 2005)

been200mph said:


> wim said:
> 
> 
> > That's where the throttle linkage hooks to.
> ...


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## been200mph (May 28, 2004)

wim said:


> been200mph said:
> 
> 
> > Thanks, been200mph. Great reading! It'll take me until tomorrow morning to digest it all.
> ...


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## tom_h (May 6, 2008)

jasonwells4 said:


> I just got my 3T Ergonova LTD handlebars from ProBikeKit(in 1 week!). They don't seem to come with any installation instructions, and I couldn't find any product manual on the 3T website.
> 
> What should I be torquing the stem-handlebar clamp to? And how about the shifters?
> 
> ...


Also apply a thin smear of carbon assembly paste, to the contact surfaces between carbon and aluminum, or carbon-to-carbon. It increases the friction so that no slipping, or creaking, will occur.

I am torquing my 3T Arx Team stem (alloy) and 3T Ergosum Arx Team bars (carbon) to 5 N-m, that is 3T's spec -- I think the instruction sheet came with the 3T stem. Works fine.

Whether it's a 2 or 4 bolt faceplate on stem, alternately tighten screws in increments, so the gaps remain uniform.


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## minh (Jul 13, 2008)

C-40 said:


> I still recommend to those who want to learn bike mechanics to learn what those small torques feel like, by hand, and not become so dependent on a torque wrench. I've never put a torque wrench on any M5 or M6 bolt.


have you ever "calibrated" your torque feel? or somehow measured it to see if it's reliable/ reproducible? i think experience counts for a lot but i would think it would be very subjective depending on conditions, e.g., at the end of the day and you're tired you think you're putting 5N-m but you're actually doing 3N-m.


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## AJL (Jul 9, 2009)

C-40 said:


> A good carbon bar should not have critical torque limitations. Most 4-bolt face plates recommend 5Nm of torque. I've never put a torque wrench to the band clamp bolts, but Shimano lists a torque of 6-8Nm in their instructions.
> 
> I still recommend to those who want to learn bike mechanics to learn what those small torques feel like, by hand, and not become so dependent on a torque wrench. I've never put a torque wrench on any M5 or M6 bolt.


I found that in the past, it was easier to get a feel for higher torque values (~40nm+) than for low ones (<10nm). YMMV.


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## Mr. Versatile (Nov 24, 2005)

6 nm.


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## dookie (Oct 1, 2007)

minh said:


> have you ever "calibrated" your torque feel? or somehow measured it to see if it's reliable/ reproducible? i think experience counts for a lot but i would think it would be very subjective depending on conditions, e.g., at the end of the day and you're tired you think you're putting 5N-m but you're actually doing 3N-m.


+1.

*but*, if you're going to use a wrench, know that they aren't all that either. the 'click' style need to be regularly recalibrated and detensioned after every use. the 'beam' style lack precision. the best are the dial versions, a la snapon torquometer. an inaccurate wrench might as well be no wrench at all...


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