Any carbon fiber experts out there?

I've been drooling over Velocraft's and a bunch of other carbon fiber low racers I've seen on the web for a while now and I'm starting to get that old familiar itch to try to put something together. First I'm interested in building a front-wheel-drive, low, but semi-upright seat commuter/touring bike with a u-joint above the steerer tube to decouple the steering and propulsion.

Does anyone out there know anything about carbon fiber construction techniques as they would apply to recumbent bike frames? I'm also looking for any literature or web sites that explain the hows and whys and whats of carbon fiber construction.

I have been to this site many times: carbon! and it has been a big inspiration and source of info, but I need MORE!

Thanks,

TD

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"When I was a child, I spake as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things."

The best CF construction method to date is bladder construction with a female mold formed from a male plug to control the amount of epoxy resin in the CF.

Buy some books to learn. You will need woodworking tools to create the wooden plug and mold, a vacuum bagging system and assorted slow set resin, kevlar with CF for lay-up and an oven to cure the resin.

Don't bother with wrapping CF over foam. That is a weak construction method that produces a uncontrolled surface with too much resin.

Cheers,
Johnny NoCom

Do you happen to know what the best way of touching up carbon fiber is? I have some scratches on one of my forks. My frame is not clearcoated - it is dull CF.

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Once a dull or glossy surface is scratched it is not easy to bring it back to the original quality. Here is a suggestion.

For a dull finish you can use a simple method like spraying a matte finish sealer over the scratches in VERY light coats. Too heavy of a coat and the spray will pool up on the surface. Craft an hobby stores sell cans of matte finish sealer.

Cheers,
Johnny NoCom

Thanks for the info Johnny!

Sandy

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"the best" is clearly subjective. Ease of construction and cost effective designs such as the Calfee Stiletto, and Lug-and-glue df's like the high-end Merlin Cielo, are examples of efficient cf construction. For homebuilders and one-off prototypes, molds and "bladder construction" is usually cost prohibitive and time consuming.

The following recumbents do not use lug-and-glue construction

M5 CLR
Birk Comet
Merlin LR
Cobra Splitter
RazFaz
VK NoCom Splitter

The Comet, Merlin, RazFazz and VK all incorporate bladder construction and have the highest strength ratio as a result. Bladder construction is time consuming and provides the best result for a complete CF with low weight.

If the goal is quick and cheap it is best to bend a muffler pipe for the frame, weld 2nd hand bicycle frames or do a lug and glue construction with carbon. The end result will never be the same as a bladder construction frame.

Cheers,
Johnny NoCom

This HPV racer & builder works with carbon fiber add ons made with foam and CF. He also has some CF bikes built from scratch

http://community.webshots.com/album/215777603vAaGEk

This latest bike is a speed missile and faster than a Stiletto with baloney bubble fairing or old school design Baron.


Cheers,
Johnny NoCom

By what pool, does your vast wisdom speak? Your a builder.. or... a structural engineer perhaps? And therefor qualified to say what is "the best" cf construction method for ALL designs? YES.. or NO? If not, your words are nothing more than personal speculation... and "pass the buck" links.

Oh really?... So tell me, what construction technique did the fastest bike on the planet employ for its cf frame?

PePe,
The fastest bike on the planet is the Varna which incorporated the male and female mold build system. No hack builder lug junk on that beauty. George Georgiev did not do the quick, cheap and easy build that most benters are satisfied with.

Cheers,
Johnny NoCom

Where's your bio?

Here we go again.... All talk and *appearently*... NO personal *hands-on* experience or design qualifications.

PePe,
I suggest you go to this site to learn something.
http://www.kreuzotter.de/

Obviously you are in a coma and you have no clue to bladder construction or what builders have been using the bladder system. My guess is you ride some lugged TourEasy for the easy lifestyle of slow riding.

Cheers,
Johnny NoCom

More LINKS.... and no substance. All you *obviously* possess is a keyboard and the ability to cut'n paste.

Where's the beef Johnny NoCome?

Like it or not PePe I know quite a bit about construction techniques. All building procedures have pros and cons. If a builder is going to do it right and design/build a frame that takes advantage of smooth complex surface and light weight, the bladder construction process is the best system to date.

On the other hand if the goal is to build something ordinary or copied that is used for for slow paced recreational riding any build method will work.

Cheers,
Johnny NoCom

And I know the difference between a digitally, self-taught phoney, and someone with last nights epoxy under his/her finger nails.

Cheers