Carbon C-Thru Road Frame (January 2007)

For a long time I have been thinking about using a framed structure to build a bicycle frame. The result of the idea is this carbon composite C-Thru road frame. The structure of the frame is completely made from solid carbon fiber rods, except for titanium rear dropouts and 7075 aluminum alloy inserts for the BB and the headset cups.

During construction, all the beams were bonded together in the frame jig, with systematic and precise control of the position and alignment in the structure and the overall geometry of the frame. Once all carbon beams were bonded together with special epoxy resin, I lashed each joint with carbon fibers to ensure their strength. This was almost surgical work, really requiring a lot of patience. The critical parts of this frame were the connections of the "main tubes", mainly head tube and BB area, so I paid a lot of attention to these areas. Then, each joint was softly sanded to have a smooth shape. On the frame, there are more than 300 joints, this painstaking work took about 300 hours of my life…

I chose internal cable routing in the frame. The frame was designed to be equipped with my Saddle Assembly, there is also the possibility of minor adjustment of the saddle height and position.

The weight of the frame is 1215 g (2.7 lbs).

A few detailed pictures of the C-Thru frame:

The fully equipped C-Thru bicycle was presented for the first time at the NAHBS 2008. Here are some pictures taken by Brad Quartuccio, Urban Velo at the show:

Thanks to the framed structure design, the frame is very stiff, later I will write my impressions and experiences from riding. It would also be interesting to compare the aerodynamic drag of this frame with traditional tubed frames in the wind tunnel (I think this frame could have a lower coefficient of aerodynamic drag)...(??)

I have built just this prototype for my biking and fun and for now, I don't suppose to build another frame. This frame is not for sale.

© Brano Meres