Build your own Carbon/Kevlar DH Hardtail

Nately27 · 03-23-2005, 01:14 PM

Hey guys, Ive been workin on this project for a couple months and wanted to share the process so anyone whose been wanting to make thier own frame can see one route to go about it. I made this one in my bedroom for the most part. The dropouts, headtube, and bb tube are all made of steel and bonded to the carbon skin. The geometry is based on a Evil Imp. or .243. Here's a shot of the jig i made out of MDF board. The axles, bb, seattube and headtube are all adjustable.

I decided to make a male mold for the carbon, and then use it as the core material for the frame. Here's a shot of the preliminary foam core.

And after many hours sanding and shaping here's the finished core:

Heres the first layer of carbon on there: the carbon is H8 weave, 17mils thick. It builds up real fast. It came from sollercomposites.com as did the epoxy and the kevlar. It comes as a dry fabric, which i wet out on a piece of plastic, and then transfer to the core. It is then covered in peel ply, and put in a vacuum bag for 4-5 hours to cure. The vacuum setup came from avt-composites.com and was one of the more expensive pieces of equipment for this project.

and more carbon on:

The finished frame with a layer of filler to smooth out the surface. This is the main downside to a male mold, the surface finish can be less then stellar. So unfortunately you wont be able to see the weave on this frame. mayby the next one though...

and heres the painted frame built up:

It rides like a dream, its really stiff and the geometry feels perfect. Im planning to have a website up with a more detailed description of the process and all the supplies soon. anyways, enjoy!

Superdeft · 03-23-2005, 01:19 PM

Wow, cool. Carbon often seems like a foreign and difficult material to handle, but it looks like it's possible for the individual to do so. Any weight for the frame?

Mattoid · 03-23-2005, 01:19 PM

Looks great Darek! Looks like ya really have a good process going there, thanks for showin us how it went together. Riding pics?

What a great post.

MtnbikeMike · 03-23-2005, 01:21 PM

SWEET!

mobius · 03-23-2005, 01:23 PM

Derek you got to much time on your hands at VT. Nice frame man mr castle showed me pics a few days ago and i was amazed.

**-BB-** · 03-23-2005, 01:28 PM

Sweet!!

Where did you get the HT, Seat tube, dropouts, and BB shell?

Inclag · 03-23-2005, 01:34 PM

That's really cool!

Nately27 · 03-23-2005, 02:08 PM

the frame weight came out to 7.2 lbs, which is right were i wanted. its in there with other burly hardtails. I guess ill find out how burly mine really is though soon

I made the dropouts myself out of quarter inch plate steel. I had to buy a drill press, from harbour freight, but the rest of the work was done with a saber saw and an angle grinder. next time itll be quarter inch aluminum and a table saw as the saber saw is a handful sometimes. The other parts came from henryjames.com, but bikeman.com has got some good items too. even disk dropouts i believe. Oh, and the seatube is carbon, i simply made it around the seatpost i was going to use. I wouldnt recomend this though as removing the post from the tube is difficult, and the carbon tube does not want to hold the post in there, i think theres just not enough friction between the two. Id use a metal tube next time. it would save a lot of trouble.

Nately27 · 03-23-2005, 02:15 PM

Quote:

Originally Posted by mobius

Derek you got to much time on your hands at VT. Nice frame man mr castle showed me pics a few days ago and i was amazed.

Thanks man! as for free time, this was basically my life outside of school and my girlfreind

Nately27 · 03-23-2005, 02:21 PM

Quote:

Originally Posted by Mattoid

Looks great Darek! Looks like ya really have a good process going there, thanks for showin us how it went together. Riding pics?

What a great post.

right now im in the process of modifying the frame:

because i didnt design in enough room for the chain in most gears, but im thinking on being back on the bike early next week. Ive got some carbon curing on it right now as a matter of fact.

Im a chimp too now! hurray!

mindlessfr · 03-23-2005, 03:09 PM

how did u get the bottom bracket to stay and how much did it cost you? just wonderin

Castle · 03-23-2005, 03:35 PM

Derek can't wait to take it for a spin! good fun!

edit: I think the frame weight was around 7.2lbs (I believe this was due to it's thickness) if my memory serves me right from the convo we had, he can tell you far more than I can....

morethanjake543 · 03-23-2005, 04:20 PM

That's cool max. Like mindless, I'm really wondering how you can get the BB shell to stay in there. Otherwise, I'd find it very difficult to trust a frame in that color.

I highly suggest you give it a flame job. It'll make it go faster, anywho.

ChrisKring · 03-23-2005, 04:23 PM

That's awesome. Good job on the home build.

Nately27 · 03-23-2005, 05:00 PM

the bottom bracket is bonded to the "inner skin" with flox and epoxy. so there are two or three layers of carbon above the bb. you can see the cutout for it covered in carbon iin the pictures Then there I layed up 6 layers of carbon and two of kevlar underneath it to really secure it to the rest of the carbon skin.