How tight - Stem on carbon steerer

[gaz]

Stem says between 8-10Nm but this seems a bit much for a carbon steerer :/

 

[HovR]

Trek recommend a max of 6Nm on their bikes, not sure what you have.

http://www.trekbikes.com/pdf/carbon_care/10TK_Carbon_Steerer_Info.pdf

 

[HLaB]

If its any help, my stem says 6-7Nm and scanning the zinn bike book it 4-9Nm max depending on the make.

 

[Wornout]

4.5nm on a Spesh Roubaix.

 

[Rob3rt]

Depends on the steerer, ignore what the stem says. You will be liable to damage the steerer. I believe the manual for your particular bike should tell you this sort of thing. If you don't have one, then check the manufaturer's website and/or contact them or the dealer. Also, if you drop the fork out of the frame, it may be marked on the hidden section of the steerer.

 

[fossyant]

What Rob3rt Says - check the handbook but around 5-6nm is the norm.

 

[GrasB]

As said by Rob3rt. Also you need surprisingly little torque on the pinch bolts if everything is put together properly.

 

[gaz]

I've sent an e-mail to the manufacturer. Not sure where the manual is.

I tightened it to 9Nm and left it for an hour or so but then loosened it to to 5Nm, didn't ride it. Damage already done from that?

 

[GrasB]

If it's been over tightened to the point of crushing then the damage is instantaneous.

 

[Rob3rt]

Hard to say and I wouldn't want to spout shoot and make you worry unduly, I would wait for the manufacturer's response.

 

[Cyclist33]

How does one measure Nm and what does it mean?

 

[ianrauk]

How does one measure Nm and what does it mean?

You will need a torque wrench to measure and Nm is Newton Meters.

 

[gaz]

If it's been over tightened to the point of crushing then the damage is instantaneous.

It looks fine. I might take it down to Geoffrey Butler and get them to give me a second opinion.

 

[black'n'yellow]

It looks fine. I might take it down to Geoffrey Butler and get them to give me a second opinion.

waste of time - unless you heard a 'crack' and/or the stem is now loose on the steerer, then it will be fine. In future, just nip it up tight enough to grip on the steerer - unless you are a gorilla, you should be able to do this without the aid of a torque wrench...

 

[slowmotion]

I think that you are far more constrained by the crush resistance of the carbon steerer rather than the strength of the stem itself. Take the smaller of the stem and steerer torque figures. My wild guess is that 4Nm would be OK.

BTW, take extra care that you tighten up the two steerer clamp screws in turn, and evenly. You don't want one edge of the clamp to dig into the carbon.