This is my home-made carbon fibre singlespeed, built by me over the winter of 2004. I was inspired by Damon Rinard's bike (now archived at http://www.sheldonbrown.com/rinard/) and the crazy/brilliant Slovak Brano Meres (http://www.bmeres.com/).
I wanted to try a newish design so thought about getting rid of the seat tube - if you've got no derailleur, whats a seat tube for? Also I wanted to see if there was any way to make a bike stiff laterally but vertically compliant, because most of the marketing you see on this subject is tosh.
First step was to make a jig. All points of contact (seat and head tubes, BB and dropouts) were all donated by my trusty old GT Zaskar. All the rest of the old alu tubes were cut away and the metal bits joined by styrofoam, cut and sanded to shape.
All metal parts were first covered in glass fibre sheet to avoid electrolytic corrosion with the carbon. Then various layers of carbon went on. Epoxy was rolled out on to the carbon cloth to wet it out, then draped over the foam. High stress areas had five to seven layers, most of the bike has three layers.
The epoxy dries in about 4 hours, so as soon as all the layers were on, the whole bike was wrapped in heat-shrink tape and given the heat gun treatment. This compresses the tape on the outside, and expands the foam on the inside, squeezing the layers of carbon together and squeezing out excess resin.
After much sanding, the final layer went on, followed by quite a few coats of gloss lacquer. The result came in at 3.1lb, showing that getting rid of an entire tube certainly has weight benefits...
I was aiming to get the bike ready for its first outing at the Merida 100km ride at Builth wells. The final coat of lacquer went on at midnight on Friday night. At 8am, I packed it in a friends car. It seemed a bit sticky, so I threw a blanket over it to protect the car. Arrived at Builth, took the blanket off and hey presto - furry bike! Lots of fettling on Saturday and the bike was ready to ride.
In the end it performed really well. The bike was really stiff under pedalling - only a little movement from side to side. It felt really solid throughout, and hey, it didn't break which was the only real success criteria. And there was no vertical compliance in the frame that I could detect.
I've been riding the bike one and off ever since, including taking it to 14th place at the 2005 SS champs in Machynlleth.
Over to you
Got an interesting bike that you’d like to tell the world (or that subset of the world that reads BM) about? We’re not too bothered whether it’s singlespeed, geared, hardtail, rigid, FS or whatever – it just has to be something unique. We’re looking for bikes that have had a lot of time invested in them by their owners. Send us a pic and some words about what it is and why it’s like that and we’ll run the best ones here...
