[offtheedge]

That debate is somewhat useless when we use common sense. Setup your shifters and brake levers loose enough that they can move on the bar in a crash - simple. You are far from "overtightened" at that point.

thank you.........why anything on your bars (minus lock-ons) would be tight enough to potentially damage them is a bad sign to start.

and i could really care less about the 70 grams, it's the feel of carbon bars that sold me. aluminum is ridged and resonates high frequencies, carbon on the other hand has a thicker wall and resonates much less and lower. Easier on the hands IMO.

 

[jvnixon]

Ummm... I work here. No I am not backwords on this one.

Torque is a rotational unit applying to the fastner. Not all bolts are the same size, in the same place - jeez some things even have two bolts. So yes - the shifter/brake lever manufacturer determines what torque spec their product needs to not slip or crush. Thread pitch, bolt position, thickness and type of material all effect how much torque the fastner needs to generate X amount of clamping force.

That debate is somewhat useless when we use common sense. Setup your shifters and brake levers loose enough that they can move on the bar in a crash - simple. You are far from "overtightened" at that point.

I once asked Easton what to torque my bar to with a Thomson stem and they said it was dependent on the stem. Are devices attached to the bar different then?

http://www.lhthomson.com/docs/stem_rev.pdf

 

[offtheedge]

i would think it is a function of the clamping surface per device.

 

[trailhacker]

Sounds like Easton told you what Sam just said. Its not the bar that determines the torque, its the component attached; the stem, brake lever, shifter, lock on grip, etc.

I once asked Easton what to torque my bar to with a Thomson stem and they said it was dependent on the stem. Are devices attached to the bar different then?

http://www.lhthomson.com/docs/stem_rev.pdf

 

[Sam B]

This is a good product to use on any stem w/ a carbon bar:

Installtion Compound

Similar products available from Tacx and Ritchey. Reduces the neccsary torque to prevent slipping. The difference is pretty noticable actually.

 

[Guntruck]

IMO peoples worries about carbon bars are unfounded. I wrecked at the last PA shuttle day and just got around to fixing my bike yesterday. I thought the bolts that hold on my Romic integrated stem on my boxer had come loose when I took it apart I found that when I had crashed I tore two of the bolts right out of the clamp. The bar is perfectly fine and had quite a few "scratches" on it before hand. The bar is one of those old non oversized FSA DH carbon bars. Anyway, if the bar can rip bolts out of aluminum I feel pretty comfertable running them. Also SamB told me that they pass all the same QA checks that their AL counterparts do.

Also, in reguards to torque specs Sam is obviously correct. A torque spec isnt directly realated to the clamping force. The clamping force is what I think should be specified here. Although its not exactly easy to measure? Additionally, using MFG torque specs isn't ever really surefire. Alot of times engineers use standard torque charts or just make numbers up. I'd trust an experienced mechanic over some silly torque specs in a manual. Use them for rebuilding engines not bikes.

 

[jvnixon]

This is a good product to use on any stem w/ a carbon bar:

Installtion Compound

Similar products available from Tacx and Ritchey. Reduces the neccsary torque to prevent slipping. The difference is pretty noticable actually.

I've seen the Tacx stuff before and i'm pretty sure its the same as the FSA compound you linked to. Tiny little beads in the grease and supposedly 30% increase in surface friction when used.