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Curtis Racing Frames - Road Racing

This series of photographs show a very interesting Yamaha 350 two-stroke twin engine racing bike. Curtis Racing Frames did a lot of work with Fred Deeley Yamaha Ltd. (which later became Yamaha Motor Canada Ltd.)

Steve Souter Team Curtis Yamaha 350 cc race bike

Yamaha 350cc two-stroke twin Steve Souter newspaper clipping

Steve Souter on the bank during the Novice race at Daytona in 1974

Yamaha 350cc race bike
Yamaha two-stroke twin
See ARTICLES Page for the image of the article.

Our shop in Richmond was just around the corner from the Yamaha Canada Racing department. The Yamaha race director gave us work to do and supplied a lot of trick parts to look and work with. We wanted to build a showcase bike featuring some of the latest suspension ideas with low weight and low centre of gravity that might be of interest to Yamaha Racing and privateers alike.

motorcycle road racing frame I designed this racing frame to use the new liquid cooled Yamaha engine very early in 1973. The engine was not at that time available to the public and the wheels shown are the mag wheels Curtis Racing was producing at the time. The bike was designed to use 18" wheels, Ceriani Road Race Forks and a cantilever swing arm with 2 shocks horizontally placed right underneath the gas tank. The engine sat 1.5” lower than on the stock Yamaha model of the time. The seat height was extremely low, keeping the rider's weight as low as possible, and the gas tank was made in 2 halves and fitted together pannier style. The bulk of the gas in the tank was placed below seat height and just above the float-bowl height of the carburetors. The bike was finished off with a Don Vesco race fairing and seat and weighed 22 pounds less than the Yamaha Motor Canada bikes of the time.

cutsom frame Yamaha road racing motorcycle

Yamaha powered custom frame from Curtis racing Yamaha custom road racing motorcycle
We showed the bike to Yamaha and a lot of interest was generated, but they were contracted to use original equipment and as a result were unable to commit themselves to the project.

Yamaha road racer prototype, raced at Daytona by Canadian racer Steve Souter Steve Baker of Yamaha Motor Canada never did race the bike, but did use some of the Curtis Mag Wheels at Daytona in the early 1970's. Three frame kits were made and one was raced at Daytona by Steve Souter of North Vancouver. In testing and in race conditions all who rode these machines were very impressed with the light weight and superb handling.

race motorcycle

motorcycle for road racing

Notes: The cantilever swing arm idea and two shocks laying horizontally came from Vincent motorcycle suspension ideas, and the 2 pannier-style gas tanks came from having seen the works Norton Lowboy of the 50's and the AJS Porcupine racer of that same era.

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If you have any information or pictures of Curtis Racing Frames from the period please Contact Us. We would really like to feature as many frames and frame modifications from that period as we can here.

Curtis Racing Frames; a sticker from 1970's

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