Times Two – Honda CB900F Cafe Racers
This project began last September. I had just sold my ‘79 Honda CB750 named ‘smooth sailing’ to a famous NFL player. I had a lot of fun building that bike and was wondering which motorcycle I could work on next. Since I loved the CB platform I figured why not go with the hottest Honda from the 1980s, the CB900F Super Sport. Less than 24 hours later I’d bought a pair of them! One was an ’81 and the other an ’82. Over the next 10 months, I customized both of the bikes to create the ‘Blue Angel’ and the ‘SS’.
The concept I developed for each bike drew on my favorite aspects of the original Honda Super Sport design. I wanted to keep the Euro-styled lines that characterized the CB900F and CB900 Bol d’Or. I found the lines of the CB900F sub-frame rather disappointing. Low and inappropriate for the cafe racer conversion I had in mind. So the first task I tackled was removing the rear sub-frame. I created a new custom subframe that had the line I was after and incorporated a minimalist electrics box into it. Inside the box, I fit the basic electrical equipment such as a Motogadget M-unit, regulator, start-up relay and battery.
After completing the subframe I moved on to the most interesting part of the project, the new seat, and rear cowl. For this, I utilized my resources as a racing catamaran manufacturer to design and fabricate the new bodywork for each of the bikes. The design of the rear cowl was done in 3D using Solidworks. Once I was happy I had a shape that matched the lines of the factory fuel tank I printed a 3D model that I could sit on the subframe. After seeing it on the bike I was able to then go back into Solidworks and finesse its shape. Once I was happy I had a design that met my styling requirements we used conventional techniques to lay the final carbon fiber piece.
Suzuki GSX-R forks replace the original CB setup. Particular attention has been paid to the triple tree which we machined in-house. There are built-in clamps for the clip on bars which provide a comfortable riding position and a cavity for holding the Motogadget Pro speedometer. In between the fork legs of each bike sits a 7 inch Jeep headlight held in place using custom machined brackets.
Another challenge was the fitment of twin 18-inch spoked wheels. The front wheel posed less of a problem. We designed the new hub in 3D and machined after consulting Buchanan for advice on which of their aluminum rims and stainless steel spokes to use. The rear hub, however, was slightly more complex to create. After being unable to make the stock rear hub work we decided to use a ’77 Honda CB750F item. It was virtually a bolt-on solution aside from some adapters. The Buchanan 18 inch rims are 3.5 and 4.5 inches front and rear and allowed me to fit Pirelli Angel 120/18 and 160/18 rubber.
Each of the bikes engines was completely disassembled, cleaned, glass blasted and repainted with high-temperature paint. I also replaced the primary chain, timing chain, and all the seals and gaskets. On the inside, each engine uses a Wiseco 985cc kit and the heads have been worked. Thanks to a Cycle X high voltage ignition the upgraded cylinders receive 3 ignitions per stroke and new 34mm Mikuni carbs feed them plenty of fuel. The bikes are yet to spend any time on a dyno to give you an exact power figure, but when you open them up the SS and Blue Angel can be difficult beasts to tame.
Story by Sylvain Carignan
- 3D print and carbon fiber seat
- Custom machined front hub
- Machined triple tree with integrated cluster and bar clamps
- Jeep headlight and custom machined bracket and ring
- Suzuki GSXR fork swap
- Custom rear sub-frame, electrical box
- All new electrical system
- Full selection of Motogadget parts
- Complete engine rebuild
- Wiseco 985cc engine kit
- Deep work on head (porting)
- Mikuni 34mm carbs
- CycleX power arc ignition
- Free flowing custom exhaust system
- new clutch
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