The purpose of the first post on this subject was 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 was, however, 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 have been produced with matching dropouts in aluminium, head tubes and bottom bracket inserts, examples being 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 Chain stays will be available soon if there is sufficient interest). Apparently data sheets would be available or all the tubing. Manufacture of the final chain stay pattern is on hold depending on interest. The proposed round tapered chain stays should produce a round to round 24mm O.D tapering to 15mm O.D over 350mm – 400mm. This should be ok for tyre clearance up to 28mm using chain stay length of around 410mm.
In the previous post I asked for some feedback on the proposals and thank the 31 people who completed the short questionnaire the results of which are as follows:
35.5% Are already interested in Carbon fibre tube to tube framebuilding and are ready to go.
12.9% Are interested and are happy to research the process themselves.
54.8% Would be interested if they had some detailed guidance on the actual building process – and that includes me!
12.9% Would be interested if they had some detailed guidance AND access to a demonstration build process
3.2% Had no interest at all (that is in fact one person).
I also asked whether respondents would prefer a round or oval chain stay design for the proposed tapered stays and this was 16 to 15 in favour of round stays.
David is the frame builder and prospective supplier of the carbon frame sets described above and can be contacted directly for purchase or more information. At present he is only wishing to supply complete tube kits for a bike rather than individual components. His business goes under the name of Revolucion Frames and the tubes are made in Taiwan. I understand data sheets are available for all the tubes. David has made some frames using his tubing and some using a flax/carbon tubing in titanium lugs as well. He can be contacted by email at: firstname.lastname@example.org, or directly on 0755141474.
An example of his carbon frame can be viewed on the Revolucionframes instagram account, though unfortunately this is not a medium I seem able to access without signing up.
I hope I may be able to post some detailed information on Carbon Framebuilding in the future, or, if there is anyone out there conversant with it that would like to send me their own documented frame build I would be happy to hear from you. In the meantime I add link to an article about the Parlee Cycles factory methods of tube to tube building which lacks detail, but you get the idea.