Carbon bike assembly - yay or nay?

[nerf]

Hello all.
I've just bought my first Carbon fibre road bike and i have a question about the assembly of the bike.

I bought it online so it came in a box. I wouldnt usually worry about putting a bike together but as its carbon, i was wondering if i should just hand it over to my local bike shop and get them to put it together. I'm just a bit concerned about how 'tight' things should or shouldnt be on the seat post and wheel joints etc?.

I wouldnt want to damage the bike by over tightening anything!

would appreciate any feedback

thanks
Nerf

[Ghisallo]

Generally there will be stickers on all the bits to be assembled indicating the correct torque to be applied. If you can can assemble a metal Bike you can do a carbon. its worth investing in a good torque wrench for low torque applications as you are bound to need it sooner or later. the carbon-meeting fixtures on my Bike generally torque to 5nm ish, which is fairly standard.

[IroningMan]

Worth getting some assembly paste, too. More or less essential for fork bungs and stems.

[sherbert90]

Make sure you grease up the seatpost as well. Once they are jammed in, they are extremely hard to get out. Trust me.

[nerf]

Thanks very much guys. I'll check the stickers on the bike tonight... i dont own a torque wrench so i'll add that to this weekends list!

I wanted it done properly for obvious reasons, not having owned a carbon ride before and only just reading about how easy it seems to damage it! its made me a bit nervous i think...


thanks again

[IroningMan]

I use a Halfords Professional torque wrench - but there are bike-specific ones that deal accurately with low torques.

Worth spedning a bit to get a good un'.

[deadtom]

does the steerer tube need cutting down too? if it does you will need a special saw blade for it

[Hard-Drive]

sherbert90 said:

Make sure you grease up the seatpost as well. Once they are jammed in, they are extremely hard to get out. Trust me.

I thought that was a massive no-no as he grease will attack the epoxy in the layup? Hence the need for carbon assembly paste in the first place?

And if both the seat post and the frame are carbon, there should not be any corrosion or sticking anyway?

Might be wrong...

[IroningMan]

swerni said:

I use carbon paste on mine so it can grip.
If I used grease, my seat wouldn't stay in place.

Personally I would take it to the LBS ( that's what I did )

Girl.

[nerf]

swerni said:

I use carbon paste on mine so it can grip.
If I used grease, my seat wouldn't stay in place.

Personally I would take it to the LBS ( that's what I did )

Out of interest Swerni, how much did the LBS charge you?

[sleep envy]

swerni said:

Hard-Drive said:

sherbert90 said:

Make sure you grease up the seatpost as well. Once they are jammed in, they are extremely hard to get out. Trust me.

I thought that was a massive no-no as he grease will attack the epoxy in the layup? Hence the need for carbon assembly paste in the first place?

And if both the seat post and the frame are carbon, there should not be any corrosion or sticking anyway?

Might be wrong...

I use carbon paste on mine so it can grip.
If I used grease, my seat wouldn't stay in place.

Personally I would take it to the LBS ( that's what I did )

My post is dry however it slides up and down no problem (have been adjusting the position over the last few rides to get it perfect)

I've not bothered with a torque wrench 4Nm is one grunt, 8Nm is two.

Hth.

[Engineer1]

Be careful a Torque wrench that reads 50Nm with an accuracy of 10% is going to read 45 or 55, a bike may well need 5Nm the accuracy of +-10% is 0.5Nm. Carbon bike torques are probably in the tolerances of a normal torque wrench.

[Roman]

deadtom said:

does the steerer tube need cutting down too? if it does you will need a special saw blade for it

A normal junior hacksaw with a fine blade is fine and use mitre saw or clamp if you have one. Pipe cutters don't work well with carbon.

I tightly wrap the cutting area with masking tape and mark the level all the way around (and prevent splintering) and also use a fine spray of water on the cut (+ wear a mask & eyewear) to suppress the carbon dust which, like mdf dust can be harmful.

Measure thrice, cut once!

[Uriel]

As has been said...carbon assembly paste and a torque wrench.

If you won't/can't stretch to a torque wrench, then at the very least get one of these:



http://www.wiggle.co.uk/ritchey-torque-key/?dest=1...

[nerf]

Engineer1 said:

Be careful a Torque wrench that reads 50Nm with an accuracy of 10% is going to read 45 or 55, a bike may well need 5Nm the accuracy of +-10% is 0.5Nm. Carbon bike torques are probably in the tolerances of a normal torque wrench.

you see this just makes me think i should have bought an ally bike!

Uriel said:

As has been said...carbon assembly paste and a torque wrench.

If you won't/can't stretch to a torque wrench, then at the very least get one of these:



http://www.wiggle.co.uk/ritchey-torque-key/?dest=1...

Thanks very much for that link, that looks nice and simple..

What about the front forks? can i over-tighten those?

[Engineer1]

Superstar components do a similar 5Nm torque set driver.

[HundredthIdiot]

I own torque wrenches but usually just use a short allen key and tighten stuff with a bit of mechanical sympathy until it doesn't slip or creak.

Assembly compound is useful for stopping stuff slipping at lower torques.

The only thing I always use a torque wrench for is my SRAM cranks, because I can't reliably "feel" 50Nm.