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fitting carbon - advice please

11 posts & 6 voices | Started 1 year ago by ex-pat | Latest reply from ex-pat

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ex-pat - Member

Just bought a nice set of carbon bits and bobs off JensonUSA - far cheaper than CRC as far as I could tell (when shipping to Aus).
Anyway, having never fitted carbon bars and seatposts before, any pro-tips that I should be aware of? (actually numpty tips welcome too).
Thinking that everything seatpost area needs to be squeaky clean so no sand rubbing around post as I tighten it.
As for controls on bar, anything I need to be aware of?
And, god forbid I decide to cut something down, is it better to take to a bike shop, or can I just launch on in with a hacksaw?

Any advice welcome.

Ta
Andrew

Posted 1 year ago #
PROLINE85 - Member

When it comes to bars, rub your finger round the inside of the stem and check for any burs/rough bits and sand them smooth if there are any. Stem bolts only need to be nipped up to hold your bars, don't overtighten them! When fitting controls have them just tight enough so they don't move and no more. Try and borrow a torque wrench if you don't have one, and when you fit your seatpost try to slide it in without moving it from side to side.

Posted 1 year ago #
ex-pat - Member

Marvelous, thanks. I may even feel moved to take a before and after photo (fixing and subsequent crash). Currently running a stem with a ghetto fix as one of the stem bolts stripped (not a good omen I suppose) and I used a handy bolt/nut combo to re-tighten.

Posted 1 year ago #
doodlebug - Member

When it comes to carbon seat posts, never ever smear post with grease !! After a few winter months the post will weld to the frame, honest.
Use a carbon paste :

Posted 1 year ago #
ex-pat - Member

Ta, now that's a pro tip!
Mind you - I live on the Sunshine Coast (Aus), so we don't do 'winter'.
Coldest we had here during the day was I think 20.c or so. Nights are a chilly affair, 10.c I think was the lowest this year. And of course, being winter, it doesn't rain much either

Question, assuming I never adjust the post, can I get away with no grease at all??? Don't grease my my other posts (ooer).

Posted 1 year ago #
Elfinsafety - Member

When it comes to carbon seat posts, never ever smear post with grease !! After a few winter months the post will weld to the frame, honest.

I've got a carbon post, use a dab of grease on it, had it about 8 years now, been out in all weathers, left the bike for months unused, never any issues. Not seizing, no mythical delamination, nowt.

You don't need much grease at all really. Just enough to enable it to slide into the frame.

The key thing here is what type of grease. I've used Silkolene RG2, which is formulated specially for use with stuff that has rubber seals, and can be used in suspension forks. Other greases may contain chemicals that can damage the outer layer of a carbon post. RG2 seems not to attack softer materials. Never ever ever use Vaseline on anything to do with a bike. It is wronger than wrong. Very damaging to rubber and possibly carbon resin.

Be useful to find out what that Pace carbon grease really is, so as to get it a lot cheaper. It's probably just some other commercially available product marketed as 'special' and costing shit loads more.

Posted 1 year ago #
aracer - Member

I've used Silkolene RG2

Presumably a silicone grease?

Be useful to find out what that Pace carbon grease really is, so as to get it a lot cheaper.

If it's anything like the (non Pace) carbon grease I have, then it contains microscopic particles which actually help with grip when tightened, so meaning you don't have to tighten your clamps too hard. Very unlike any normal commercial grease.

Posted 1 year ago #
Elfinsafety - Member

Presumably a silicone grease?

As far as I know, no. It's specifically designed not to damage rubber seals, which probably makes it fine to use with carbon. Well, it worked for me!

About £8 for a big tub. Lasts bastard ages (I only ever bought one tub, in 1997, and still have some left!). I use it for owt requiring greasing on a bike, other than where copper grease is used to prevent seizing of things like BBs.

Posted 1 year ago #
Skyline-GTR - Member

Pace, and other carbon fixing paste or grease is a composite material comprising a solvent carrier and polymer balls.
It works in this manner:- The inert solvent "grease" is a carrier solution to get the polymer balls into position. The polymer balls then do all the work. They act a as a lubricant to allow the post/bar to move for adjustment by rolling like bearings, but when a clamping force is exerted on them, they ovalise and prevent unwanted movement at low clamping forces. This means the product can be held firmly in place without being "hoop loaded" and creating stress raisers in the composite weave.
It also acts as a good barrier against chemical bonding.
It is carcinogenic, and care is needed when using this type of product.

As for cutting carbon composites, leave it to a professional, or at least cover the area in tape and use a respirator or dust mask.
The resins used are extremely carcinogenic and should be treated with great care.

Posted 1 year ago #
ex-pat - Member

Thanks folks. So...
1. No cutting - I'm happy with that for lots of reasons*
2. Grease - minimal, and I have some silicon grease (water system stuff), reckon that'll do. Though Skyline's post above makes it sound far more technical than that!

Can't wait.

* Me & cutting don't work - have since realised not to trim sideburns to try and make even height, otherwise I oscillate my way up my head. Can imagine having a set of bars that are 200mm wide...

Posted 1 year ago #
ex-pat - Member

And now have re-read Elfinsafety's post.
So, no, not silicone grease.
Lube shop time.

Posted 1 year ago #