The purpose of this post is to try and ascertain the interest in the frame building community in constructing their own carbon fibre frames using tube to tube construction. I have only dabbled in adding carbon to my steel frames, but the techniques for building carbon tube to tube frames appears to be much the same, in as much as they can be cut and mitred and assembled and glued in a standard frame building jig. I have been put off by the subsequent wrapping of the joints to finish off and strengthen the build, feeling this has to be done properly. I am given to understand that it can be completed without the use of an oven afterwards, presumably by using the correct type of epoxy and that wrapping of the joints is not as difficult as it may appear. My own perusal of the internet has only come across projects to produce moulded frames, which as a steel frame builder, is a completely different way of working. It also would require more space than I have available. I have not found any books on the subject and there seems to be one teaching course in the USA, in Tucson, Arizona (https://www.framebuildingschool.com/carbon). There is however some useful information on several manufacturer websites, albeit rarely related to bicycle construction per se.
I have, however, been contacted by a third party frame building enthusiast who has built carbon and carbon/ titanium frames in a restricted environment and is keen to offer some help and instruction in using the complementary tube sets he has had made. These will be produced with matching dropouts in aluminium and head tubes and bottom bracket inserts, examples are shown below. The Tubing is Toray T700 unidirectional.
Early size options are below: Seat tube 600mm x 34.9mm O.D x 31.6mm I.D for 31.6mm seat post. Top tube 600mm x 34.9mm O.D x 31mm Down tube 660mm x 41mm O.D x 38mm Head tube 200mm x 48mm O.D x 44mm I.D for EC44/ZS44 Head set BB sleeve for T47 Bottom Bracket Seat Stays 508mm x 16.5mm O.D x 14mm I.D Chain Stays 500mm x 20mm O.D 16mm I.D Round to Round. (Tapered Chainstays will be available soon). Apparently data sheets would be available or all the tubing. Manufacture of the final chain stay pattern is on hold and he would appreciate any feedback on chain stay design. I therefore attach the proposed chain stay mandrel, which should produce a round to round 15mm O.D tapering to 24mm O.D over 350mm – 400mm. This should be ok for tyre clearance up to 28mm using chain stay length of around 410mm.
Click for Chainstay Mandrel Diagram (Pdf)
Given all the above information I would be grateful if anyone would like to complete the attached TWO QUESTION questionnaire to ascertain interest as to whether it is worth further pursuing this niche area of custom framebuilding.
PLEASE CLICK THE FOLLOWING LINK TO ACCESS THE TWO QUESTION QUESTIONNAIRE:
Any other comments would be welcome