1973 Honda CB400F - March 2020 Window Bike

The Raptor - 1970's High Performance Honda Mutt by Ripple Rock Racers

Our March window bike was built by our friend Kemp from Ripple Rock Racers and is a project that has finally come together after many years of being at the back of his mind and his garage. We've had a number of Kemp's bikes in the window over the year's (The Hybrid, The Roadster, OZ, CR Special and his Ducati single was actually the 2nd bike we ever had in the window) Here's a little info on this really trick build dubbed "The Raptor": 


I started this build 10 years ago gathering parts to create an homage to Yoshima and his "Yellow Peril" that roamed the streets and racetracks of southern California back in the mid 1970's. The whole idea of the little guy beating Goliath has always appealed to me. A Honda CB400F that could slay a Kawasaki Z1 like Yoshima's did, that was my build plan. Unfortunately customer builds meant it was constantly relegated to the back of the garage till this past winter when things finally came together.

The build began with a 1973 CB350F frame which we reinforced to handle the additional load and forces generated by a big bore engine and massive brakes. We manufactured our own billet triple trees with Mechetronics Specialty Services to adapt 35mm forks from a 1080 CB750F. The forks were modified using CB550 springs and Race Tech Gold Valves. We built aluminum caliper plates to adapt the Brembo calipers from a Ducati Paul Smart model. The front wheel is a CB750 hub with Buchanan spokes laced to a WM3 DID Shouldered Aluminum rim. Adapter plates were machined to mount FZ600 discs to the hub. The rear wheel sports a 1962 Super Hawk twin leading shoe rear brake laced to a WM3 DID shouldered rim. Tires are Heidenau Vintage Racing K45.

The engine was sourced from a CB400F. Cylinder castings were bored to accept CB500 sleeves fitted with CBR 125 High compression pistons. Intakes were straight bored for 26MM Keihin CR Carbs and oversize Kibblewhite valves, springs and titanium retainers were fitted. A Webcam 63B cam with a Yoshimura HD cam chain and a TT400 slipper guide and adjuster were added. The oil pump was gutted and rotors from a CB750 were machined to fit. This mod would double the oil pressure delivered to the custom built Carillo Rods which were fitted to a lightened and balanced crank. Engine work was done with Gord Bush Performance where we built two of these engines, one for Steve and one for me.

Bodywork consisted of a super light aluminum road race tank and seat originally designed for the CB350F by Halcott in England, paint is Candy Apple Metalflake Tangerine by John Connery, seat was custom upholstery by Bespoke Original design. Little bullet fairing and fiberglass front fender from my stock of goodies. Brake master is GSXR750, Headlight by Bates, aluminum mounts built with Mechetronics and all electrics, switches , gauges by Motogadget and wired by Noy the Cuban.

I've run the liitle beast in the garage and the sound from the Yoshima pipe is awesome. We expect about 65hp at the rear wheel as per Steve's engine. I named the bike The Raptor as it's little, fast and aggressive. A predator with a small footprint designed to destroy much bigger prey on the roads and tracks of southern Ontario.