This is my bike
I started classic racing with a Honda XL250 K0. Lovely bike for short track but a litle bit boring in the long straights.Than I switched to a 750 Honda, an overbored Four Daytona replica. Wiseco pistons, high compression, Keihin racing carburators, Megacycle cams, almost hundred HP. Very fast bike, I was always first… untill the first corner, but from that point I’ve just fought against my bike, not the competitors. Than I’ve found the golden mean: A single cylinder English racer.
The heart of the bike is a BSA engine, made by a Dutch guy, Jan DeJong. He’s specialized to manufacturing beautiful Gold Star replicas, with larger valves and compact combustion chamber. I’ve still bought a six speed Quaife gearbox and a Newby cluth and gave them to my mate who’s welded a Seeley MKIII frame around it, with steering angle and rake of a Honda NSR250. First I used a Roadholder fork, shocks and wheels from my own stock. My other pal made the petrol tank from thin alumunium sheet (maybe too thin, it suffered already two cracks because of the heavy vibration of the BSA engine.
The result was a well mannered bike, weights less than 120 kg, realy great pleasure to ride it, untill you dont want to push realy hard. I remember I was in Rijeka racetrack in Croatia, there were two straight followed by tight corners. It was a nightmare, when I tried to shorten the brake distance and turn in a steep angle after it. As I catched the brake lever, the front end started to jump forwards-backwards like crazy during the braking, and then up and down in the corner. As I got second time in the gravel, I started to think about how to improve the stiffness of the suspension.
As I learned to be an engineer, one of my teacher (he was a very practical guy) adviced us to modell the structures from soft materials, e.g. aluminium wires and test how they distorting under load. I’ve done it according his instruction and saw, the Seeley MKIII frames weak point is the part above the cylinder head, where the uper tubes are crossing eachother. To make the frame stiffer, I welded a downtube from the steering head to the engine case. The first problem solved, the bike was smooth even at hard braking. The jumping through the corner caused the fork: the damping was „accidental”, not adjustabe, and the yoking of the front spindle was too weak. To modify the old Roadholder was a disaster, so let’s create a new fork! My Ceriani replica GP35R was born after many years developing and testing, with fully adjustable damping system and wide yoking clamps for the spindle, see www.caferacersuspension.com/forks.html. Works perfectly.
I really enjoy the bike now, sounds and runs easily like a modern supermoto (I raced against them in a drag weekend, okay, some of them were a bit faster, but only some tenth of difference.) I never have to wrestle with it, like the big Honda four, I’m feeling she is for me and not I’m for her.