Workshop tales, trials and disasters.
Maintenance tips, techniques and myths.
Technical discussion, description and outright lies
14 posts • Page 1 of 1
If you want to , why not do it.
It is possible.
Italian tube companies like Columbus, Oria, and Dedacciai make carbon tube sets that every tom dick and harry can buy.
Hell they even make lugs as well.
All you need is knowledge of glues.
And a frame to fix it in before the glue hardens.
If you want to make a monocoque frame - that is another story. Years ago I worked with fiberglass and we made tubes that were carbon coated. This was difficult as we had to mix in to the epoxy such additives as uv protection, heat resistance and so on. Then it was difficult to get the heat right for the hardening process. You would also have to make a mould to lay the fibers in and then some way to hold the fibers there while heating them(pressure). You would also need a knowledge of what fibers to put where and how many layers and so on and so on. All in all I wouldn't recommend a monocoque frame.
So why not just buy a frame?
This is an old article but worth a read: http://www.sheldonbrown.com/rinard/carbon_fiber.htm
Also have a look at something more recent: http://www.bmeres.com/carbonframe1.htm
life is unfolding
That second linked page has some cool builds - bamboo - self made carbon seat, and cool pics of how to (not that I can/would).....
What is it with cycling? 30+ kmh and lycra???!!!
Carbon frames are much more affordable now than when these articles were written, and there are quite a lot to choose from.
I'm sure there is someone out there who will build a custom frame if you can't buy what you want off the shelf (I've sometimes thought that a carbon touring bike would be a good thing to have built, given that few people would put "carbon" and "touring" in the same sentence, never mind mass market such a bike.)
That leaves the enjoyment of the actual project as a reason to build your own carbon frame, and also perhaps the develpment of skills that might be useful at other times. Might be worth the time if this is your motivation.
life is unfolding
One of my coworkers is nearing completion of a homebuilt carbon fibre bike, not sure what techniques he's using though (there are a number of ways you can go about doing this, buying tubes and bonding them together, vacuum bagging CF onto a sculpted foam core, or forming parts in a mould).
The bike he's making is a recumbent, which probably partially explains his decision to built it himself. Carbon fibre recumbent frames are still very rare and expensive so going down the homebuilt route makes sense from the point of view of getting exactly what he wants for an affordable cost.
Hotdog, I've been a bit quiet on the list recently - but this caught my interest, as I've been contemplating something similar. My idea is to use premade tubes. I think a recumbent lends itself to this approach, as the frame configuration is very simple. I'd be very interested in chatting to your workmate about his experiences.
There are a couple of sources of premade tubes, http://carbonfibretube.com/ is one. I also know a few people in the sailing industry who can source them as well.
To join the tubes, I was planning to wrap with carbon cloth, wet out and either shrink wrap and bake, or simply allow to cure. For a simple recumbent frame, there needs to be joins for;
- bottom (front) bracket
- steering head
- chain stays to main tube
All these are 90 deg angles, which should make the jigging process fairly simple
I'll quiz my colleague about his construction techniques and see if he fancies having a chat with a fellow homebuilder. I'm sure he will, he's a friendly guy. I think he was going down the foam core and electrical tape compression route, at least for the main frame components, but I could be misremembering.
I'm very curious to see the results of his labours myself, it sounds like a pretty ambitious design including nice little extras like internal cable routing and so on. Apparently it's almost complete, he's just got the stem/tiller and handlebars to build, then some finishing work and installation of the drivetrain and brakes. There'll be a slight delay though, as he recently stacked his regular bike when he encoutered an oil spill and broke his wrist
The premade tubes approach is interesting, for a simple 'stick bike' style recumbent frame it would speed up the process of putting your own carbon fibre bike together enormously. It'd end up either heavier or more flexy than a monocoque frame where there's more scope for optimising frame shape and the number and orientations of the carbon fibre layers but I bet you could still manage to make a pretty good frame with a bit of thought and care. May even be easier than homebuilding a steel frame.
Have a look at the site below. The Groundhugger XR2 carbon do it yourself recumbent.
You might get a few ideas. I think a school in SA did well in the Solar Challenge a couple of years ago with one of these. They had a lot of pictures of their build if you can find the site. There may be a link to it from Riley.
good discussion, lots of good info here.
rdp_au, the poor-mans carbon fibre frame has only carbon fibre tubing fitted into lugs. By taking pre-finished carbon fibre tubing and connecting them with carbon fibre (lugs) I don't think you are getting the best out of the material. Better would be to either use standard lugs (and gluing) or making a complete monocoque frame. The rational is that joining existing tubing you are not only using more material... but are also not improving the strength. Weight saving and high strength (in certain directions) are the key material benefits of carbon fibre.
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