Info on carbon parts mfg process, interesting stuff.

greenspun.com : LUSENET : MV Agusta F4 : One Thread

I have no idea if this is all 100% fact. However, I am pretty sure that the source of this info does not have much of a stake in it since they seem to not manufacture carbon parts on their own. They are just telling you about what they sell. It's worth reading. I have known this for a while because my cousin used to make carbon skateboards and such in his backyard, telling me "It's just like fiberglass". However, at some point during my many hours of watching motorsports on TV (F1, Sports cars, bikes), I heard that making "real" carbon parts is indeed something like rocket science. This article tends to confirm that.

http://www.mototrends.com/carbon-facts.asp

I don't buy carbon stuff anyway, I figure any money spent on that could be better spent on Slim Fast at this point...

-- Andy Ruhl (quadreverb@yahoo.com), January 02, 2003

Answers

oh sure now you post your secret!!! After I just got a complete body set from QB Carbon. I mainly got it cause I wanted some race body work and no one makes it. Dwight Mitchell say Sharkskinz is making some for him (though his current stuff is QB), but if they are they are only doing it for him. As they tell me they don't and aren't planning on doing MV stuff.

The QB stuff just showed and as I've never purchased carbon before I can't speak on the quality of it as it just looks like bodywork to me. If I wasn't going to have it painted I'd be disappointed a little bit as the weave pattern isn't consistant in a couple of places, but again I don't know what the standard is and again it really doesn't matter as its going to be painted. But I've also seen that with other carbon products.

The biggest thing is that, they didn't have the race molds so the lights had to be filled in after the stuff was made. In doing so they aren't exactly flush so you still see the outlines of the lights. I talked to the place that is going to paint it and they said that isn't a real problem as they can fill it to make it flush before they painted. Had I known that then I would have just had that done to my stock body work and spent that cash from the QB stuff on more trackdays for next year! The price you pay for not doing research before you buy!!! One last thing, please don't think I'm baggin on QB Carbon. They were great to deal with, told me up front about the mold and having to fill it after the fact and about the lines showing. They also kept to the time line that they promised. Haven't tested the fit yet as the bike is in the shop having some work done

-- TP (tpoole@xnet.com), January 02, 2003.


I think there probably isn't much choice for bodywork for the MV other than Carbon or stock though is there? I haven't seen any bodywork from a company such as Sharkskinz or anyone else made out of fiberglass or ABS or something. What that means is that what you did is probably your only choice other than stock bodywork.

I'm not really bagging on this stuff either, you just have to get what is available. I think what that article is for is to set expectations. Apparently it's not difficult to make something out of carbon fiber, indeed someone can do it in their backyard. Making something out of carbon fiber that has the proper strength and pattern (it has to have a uniform pattern to be strong) is something else though, as the article confirms. It makes sense that making a fender for a motorcycle is something totally differnent than making a wheel or an F1 chassis.

Again, what can you do? QB Carbon was probably your best alternative other than the special parts stuff, which we still aren't sure who actually makes?

When I've lost another 15 or 20 pounds off my ass, then I buy all this carbon stuff. Till then, I gotta stop eating donuts!

-- Andy Ruhl (quadreverb@yahoo.com), January 02, 2003.


Last spring I did a ton of research on carbon fiber (or fibre for you Euros!) as I'm interested in making some of my own parts. I even purchased several books on making carbon stuff, though some of the mathmatical equations (okay, most of them) were a bit hard to understand.

From what I understand, that article was just about right. Most raw carbon suppliers will recommend you buy carbon specific resin, though if I ever do make anything, I'll use prepreg. The only real disadvantage to using prepreg is that since all the chemicals are already mixed together and curing, it doesn't have a long shelf life.

I would guess that most parts are at least vacuum bagged, though my Casoli front fender has a pool of resin on the underside, but that could be caused by not using enough breather fabric (which absorbs the excess resin) when bagging. For bodywork, fenders, and other non- stressed parts, an autoclave isn't neccessary. However, anything that will be stressed (like subframes, handlebars) should be autoclaved.

Anything part that has to deal with excessive heat also has to be autoclaved because the resin has to be a high temp resin. In order to cure it, it would have to be heated when building the part because curing at room temperature wouldn't be enough.

One other thing to keep in mind is that the weave pattern isn't meant for looks, but plays a key part in the strength. The strength is in the direction of the "grain". The standard checkerboard "over-under" pattern provides a more uniform strength from different angles. Sometimes you'll see parts (like on race cars or aircraft) where the fibers all lie one-way. This provides the maximum strength-to-weight ratio.

Hey, that all made me sound like I actually know what I'm talking about!

-- Brad Cowell (bcowell@sbcglobal.net), January 02, 2003.


If anyones interested you can get a full fibre glass fairing including tail section for £400 or $600 approx, in race fairing or street. regards Peter

-- peter Arrigoni (peter@longar.co.uk), January 03, 2003.

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