Hey Peaman, I’ve read that joining metal (aluminum or titanium) bike members together with carbon and epoxy is a good way to go. However, it takes extra CF and technology to join the dissimilar materials. The monocoque CF construction method entices me. Bike parts manufacturerers are producing press-in bearings for just that application, as CF doesn’t hold threads well. Also part of the formula is esthetics. Some bike buyers expect their bikes to look like bikes. In CF that translates into joining CF tubes with CF. Monocoque translates into shapes which don’t use tubes. The design saves weight by eliminating thick joints, and by putting frame parts where they resist forces better. I’ve seen some monocoque CF recumbents on the web. They’re mostly low racers because the form allows the frame to support the seat directly… a pretty small market segment. Try talking your wife into laying on her back, pedaling down the road with her feet in the air. 
As you can see, the human form causes severe recumbent ('bent) design compromises. Start changing materials and the problems rise exponentially. Thanks for the encouragement. Back to the drawing board…
I’ve had a CF Kestrel 4000 since the introduction year…I LOVE that bike…Whatever energy goes into the pedals is transfered to the wheels…And road shock is nicely dampened… http://www.hollowsurfboards.com
I have used additive F it works like a champ no sanding in between laminate and hot coat.Even down here in the Texas heat and humidity.I was wondering about using polyester on my hot coat to save money.Can it be done without having to sand before you hot coat.
Noodle, If you build a carbon fiber recumbant, the carbon tubes can be reinforced two ways: filling the tubes at key points with expanded polystyrene plugs to maintain the tubes circular form, averting distortion and collapse... also the final wrapping of the carbon with kevlar helps shield the rider from jagged carbon shards in case of tube breakage. A great resource is Jack Lambies “Composite Aircraft Construction For Homebuilt Aircraft”… regarding carbon tube construction see chapter 8, which discusses construction of the world famous Gossamer Albatross/Condor projects (human-powered flight). Really good stuff! Dale
I’m sure you’ve read some of Sheldon Brown’s stuff on bikes. He has an article on building a CF bike in a garage but I don’t think he actually he wrote it. It has some great info on epoxy stuff in general. Harris Cyclery is a great resource for bike tinkerers. If he was in to building boards instead of bikes, I guarantee Sheldon Brown would be a regular on Swaylock’s! http://www.sheldonbrown.com/rinard/carbon_fiber.htm
Thanks Terry, I’ve done polyester hot coats in the past but there is always a chipping problem. Most of the more exprienced guys I sell to don’t anymore. There’s only 12 oz of resin in a hotcoat for both sides (shortboards). You aren’t going to save that much money. Quality of the finished product is worth more.
Dale, Thanks for the book tip. I’ll try and find it at the local library. Aircraft and bicycles seem to have many similar technologies. Wicks and Rans aircraft companies supply some of the better 'bent parts. I’ve heard of the EPS filler trick, but wondered if it was strong enough. Surfboards need wood stringers for the same purpose. I thought about building my own CF tubes up from wood, instead of flourescent tube, but I’m worried about sealing the wood from moisture. Short term, the seal will hold, but eventually the wood would lose its properties from seepage. John, Thanks for the links. I’ve been to Sheldon’s site. It’s chocked full of cool bike stuff. He has the bible on tire-to-wheel info. I’ll look for the epoxy stuff. Paul, I couldn’t find the Kestrel 4000 in a Google search. Is it a ‘bent? …monocoque? I’m with you about flex vs power. It’s hard to find a flexy bent that won’t launch on the big bumps, or lose road feel in the crank. I think long wheelbase (LWB) is the preferred sales tool while people get introduced to recumbents. LWB is easier to adapt to. The LWB format requires a stronger frame. You’re suspending a +/-200 lb shifting load between wheels placed 6’ apart. Somebody’s performing the first long-term, large-scale study of the health effects of diamond frame bikes on riders. It would be nice to be well placed when riders discover they’re rendering themselves impotent and crippled.
The Kestrel 4000 was the first monocoque bicycle frame that went into any kind of mass production…They were made in Watsonville CA… When I was in the triathlete phase of my life, it was the bike to have…I got mine in '88 and my wifes in '89…They still have a magical feel, even after thousands of miles… The tubes are NOT round…Very aero…The CF fork was a must have extra…A premium ride that titanium can’t match… Paul http://www.hollowsurfboards.com