Curtis Racing Frames - A History

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Denis Curtis

Denis Curtis, CMR owner, was born in Lincolnshire, England in the late '40s. He served an apprenticeship with a local engineering company called Ruston-Bucyrus Limited and became a Jig and Tool Design Draftsman. He attended a local Technical College during this time and gained a Production Engineering Degree with the City and Guilds of London Institute.
Denis was influenced by many racing motorcycle frame builders of the 50s, 60s and 70s, including Ken Sprayson of Reynolds Tubing and his work with many top riders of the era like Mike Hailwood . Other influences include Colin Seeley with his solo and sidecar frames and the Rickman Brothers and their Metisse frame kits for all types of motorcycle sport. Also of note was Alf Hagon with his V-Twin JAP Sprint Bike, and the Eric Cheney Organization whose Motocross frame exploits were of the highest standard.

Denis Curtis started building and modifying frames for road racing and sprinting (drag racing) in 1965 in the UK. His first projects used Velocette and Vincent engines. After emigrating to British Columbia, Canada in the early 1970's and working and road racing for Fred Deeley Limited, he started his own manufacturing shop called Curtis Racing Frames in Richmond, British Columbia, Canada.

Curtis Racing Frames operated from 1973 to 1977, producing motorcycle frame kits for all type of racing and street activities. There were a total of six employees. The shop was just across the road from the Fred Deeley Yamaha HQ, which later became Yamaha Motor Canada. The racing division of Fred Deeley Yamaha and Yamaha Motor Canada were frequent visitors to our shop. We enjoyed a close working relationship with them and also with Clarke Simpkins Honda, the Honda motorcycle distributor in BC at that time.

At the top of this page are a selection of links to pictures of some of Denis Curtis' exploits with motorcycle racing and motorcycle frame building from before and after 1970 when he emigrated to Canada. 

The 1960's

First ever road race – 1965. Riding a friend's BSA 350 cc Gold Star in a Clubman's Race at Cadwell Park race circuit near Louth, Lincolnshire, England. I finished 3rd. The bike was absolutely stock except for a fiberglass gas tank. Details: ran on Avon tires, used a period 'Everoake' 'pudding basin' helmet and a set of used 'Lewis' leathers. I rode the bike to the event, taped up the lights, put on the number plate and went racing! Because I was only 16 years old, I had to get my mother to sign the waiver. My father didn't know I was racing.

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My home track, Cadwell Park in Lincolnshire. This is the Vincent Owners' Club High Speed Trials, 1967. I'm waiting for the 'out' on my Curtis Vincent Special #32. In this line- up is Roger Slater on bike #2. He became the Egli-Vincent distributor for the UK.

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A photo of the first time the Curtis Vincent Special was raced at Cadwell Park in Lincolnshire. The bike used a 998cc Vincent V-twin engine with the standard transmission/gearbox removed. The engine was mated to a Manx Norton 4-speed gearbox/transmission. I built this bike in 1966/67 to compete in the Clubman Open racing class.

I used a Manx Norton frame and re-engineered it to put the Vincent engine crankshaft on the same centre-line as the original Manx Norton engine. The frame had to be extensively modified – as you can see from the photo, the front down tubes have been removed. The engine had been modified for racing to “Lightning spec”. I even used the Manx Norton central oil tank. Dunlop racing tyres were used and Girling shocks. It was a cold day and I scared myself silly on this thing. It was my first outing on those old triangular tyres and you needed to get some heat into them so they would work properly.

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I had two set-ups for different race tracks. For Snetterton and the long track at Cadwell I used 1 & 5/16" Amal 5 GP2 carburetors on special adaptors. For shorter tracks I used 1 & 1/8" Amal monoblock carbs. The bike had lots of torque, and handled really well. After a couple of seasons I realized that I wasn't a very good road racer, as I was more interested in building great handling machinery than racing them.

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