heirfaus

I will be getting my used cf bars in the mail today. Does anyone know how to install them. I have completely disassembled (and successfully reassembled) my bike before so know I can install them, I just am not sure about how much to torque on them when installing, or any other general tips. If you know, chime in! thanks

dperreno

What type/brand/model of bar? Straight? Road? Tri?

What type/brand/model of stem?

You need to give us a little more info to work with here...

HillRider

All good questions. Also used carbon fiber parts are really a crap shoot, particularly bars and stems. Even if you install them properly and use the correct torque, you don't know that the former owner did.

fietsbob

have an open face stem, and a 1/4" drive torque wrench?
how about an insurance policy paid up,
without exceptions/exclusions for using 2nd hand Carbon fiber handlebars?

Rob P.

So far no real help for the OP....

You will need an INCH pounds torque wrench and some carbon paste. You can get the carbon paste in a large tube (which you will then have laying around forever with no other use) from your LBS. You also need to go to the bar mfg's site and see what the bolt specs are for your particular bar. This is usually around 4 NM which is about 35 inch pounds but you MUST check your mfg's specifications - don't just guess.

Chart for NM to inch pounds:
https://www.thetoolhut.com/Torque-Con...ch-Pounds.html

Coat the bar where it mounts inside the stem plate and put it into the Stem. Run in the bolts finger tight and adjust the bar to be centered and in the proper position. Using the torque wrench tighten the bolts in a cross pattern until tight. If it's a 2-bolt plate, tighten each bolt a little bit and then do the the other one then come back and tighten the first one a bit more and continue swapping back and forth until the bolts are tight. You want to draw the plate tight in an even manner.

DO NOT FORGET THE CARBON PASTE! It's really nothing more than sand in silicone gel but it's really important.

Bianchigirll 

actually the OP did not give us much information. for all any of us know the OP has a standard style quill stem with a 25.4 clamp. should that be case any information other than you need a different stem would be usless.

also I do agree I would never buy used carbon bar or stem. actually I very seldom buy used alloy bars, you just never know

heirfaus

Sorry everyone, I guess I spaced on the specs, my apologies. The bar is 26mm, 189 gram Forte Carbon bar. In the pictures it looks new except for very minor contact scuff on the mounting area. Looks so good it almost could be a take off. I have a new Ritchey WCS 26mm clamp 110mm length stem.

I've done tons of head gaskets on cars, so I'm very familiar with torque wrench use and equal tightening sequences.

Edit: Oh yeah, obviously the WCS is open faced

HillRider

OK, it's a 4-bolt removable face plate stem so Rob P's advice is germain. Typically the recommended torque is 4 to 5 N-m but I'd consult Performance (Forte is their house brand) for a specific torque recommendation. The use of assembly past is a worthwhile precaution.

operator

No actually it's not really important. It's only needed when there's an issue that maximum normal torque on fasteners do not solve.

I can count on one hand out of the hundreds we've assembled and repaired that required carbon compound to hold the bars. If you *need* carbon compound to hold a bars with a stem at the correct torque, something is not right.

Rob P.

If you are assembling carbon components to aluminum components without the paste there is definitely something that is "not right." The Silicone is there to stop electrolysis between the carbon and aluminum which is a VERY BAD thing that can cause catastrophic failure in a very short time. The paste is not just for grip although the grit in the paste helps when parts tolerances stack up and you have a bit of a loose fit.

This is such a well known thing that even carbon/aluminum frame builders have to use a special glue which has "beads" in the glue to keep the 2 parts separated.

operator

Yawn.

We should be seeing dead customers and broken bars left right and center according to you. When you actually work at a high volume, high end road shop then you can start posting something that isn't 100% bull****.

You must think I don't actually work in a real bike shop that puts bikes on the road.

Rob P.

Whatever.

You can do what you want. I, however, will ALWAYS recommend the SAFE course of action using ALL of the proper techniques and materials rather than recommending a "short cut" to someone who has no experience or knowledge and is asking for help.

heirfaus

Thanks for all the input everyone! Got them installed. LBS hooked me up with some free paste and torqued it to 5nm for me 100 grams lighter than my others, much more attractive and absorbs a noticeable amount of the road vibration. Very happy with the upgrade!

HillRider

I think you are overstating the problem in this case. Certainly grease on aluminum seatposts (and quill stems) used in any metal frame is essential and "assembly paste" is the proper thing to use on carbon seatposts in any type of frame but that doesn't extrapolate to handlebars and threadless stems.

Electrolytic corrosion doesn't seem to be a problem and seizure of the bars in a removable faceplate stem is a non-issue. I have aluminum threadless stems installed on steel, carbon and aluminum steerers and don't seem to have corrosion problems with any of them and have never had, or heard of, a failure from dissimilar metal contact in this area.