BSA A90 Typhoon 900 cc
Currently in the workshop
BSA A90 Typhoon 900 cc
November 2026
In the '70s and '80s, Californian petrolheads were deeply entrenched in racing culture - whether on tarmac, dirt, or desert trails in Baja California. These racers demanded hybrid motorcycles that could dominate both the circuit and off-road terrains. This era also saw the rise of a special breed of enthusiasts - the "Beach to Bar Heroes" - whose machines were as much about style as they were about performance.
With the exciting news that the iconic British brand BSA has been resurrected under the ownership of Indian industrial giant Mahindra, we at JETS felt compelled to honour this legendary name. To celebrate BSA’s return, we embarked on a project to reimagine what might have been if those heady days of the San Diego Antique Motorcycle Club's (https://www.sdamc.net/) festive gatherings at the iconic Del Mar Racetrack were still alive today.
The project began with an old A10 frame that Sean recommissioned, ensuring that while modern mechanical specifications were seamlessly integrated, the frame's essential vintage look and feel remained untouched. On the mechanical side, we turned to none other than Geoff Dewhurst of SRM Engineering
(https://www.srmclassicbikes.com/) world-class specialists in BSA performance. Geoff rebuilt an A65 motor from the ground up, utilizing a 750cc barrel and a longer A10 crank to achieve a powerful 900cc configuration—reminiscent of the sidecar racers of that era who favoured a torquey, robust engine.
Many custom-machined, high-tech parts were used throughout the build, with a focus on optimization and track usability, rather than raw, uncontrollable power. The result? JETS' BSA "Typhoon" 900—a perfect homage to a time when motorcycles had character, individuality, and a story to tell.
And this is just the beginning. Stay tuned for more builds that celebrate the spirit of that unforgettable era in motorcycling history.
Technical Specs
General
Design & Build:
Design: Jeff Duval
Frame: Sean Reynolds
Motor: SRM Geoff Dewhurst
Build: Sean Reynolds
Engine
Full race A65 donor engine with 750cc barrels & pistons cranked to 900cc using dynamically balanced A10 crank and rods.
Gas flowed head with competition valves, springs and rockers together with appropriate lift cams.
Crowned by a pair of muscular Amal Mk2 Concentrics, optimising useability instead of all out uncontrollable power!
Electric starter
A much needed custom development BSA A65 unit starter motor kit - Shropshire Classic Motorcycles (triumphbonneville.com) fabricated by Ark Engineering but exclusively distributed by Shropshire Classic Motorcycles.
A piece of advice for this application: This is a complex transformation requiring a high degree of detailed expertise about BSA and Triumph motors of yesteryears…
Transmission
4 Speed OEM Tranny also rebuilt from scratch at the same time as the motor by said SRM Engineering.
Chassis
Recommissioned and modified from scratch by JETS’ Sean Reynolds.
Suspension & Steering
Competition Ceriani 35mm adjustable front fork assy and rear shox by by Falcon Shock Absorbers.
Wheels & Brakes
Chromed 21” & 18” ally wire rims with S/S spokes by Apollo Wheels of Los Angeles.
Full Beringer competition brake assy and hand controls.
Iconic K-Tech 11.5 floating discs.
Instrumentation
Despite being an in depth restoration of a racing machine, Jeff and builder Sean Reynold (who organised the complex e-trics & e-tronics wiring) decided to make the scoot road legal.
Bodywork & Seating
In keeping with other new JETS classic racing projects, Jeff paid immense attention to making the project rideable by seasoned riders.
Thus he and Sean are to be credited with most bodywork finery.
Ergonomics
An iconic competition machine recrafted to be road legal and comfortably useable by seasoned riders.
Photography
Max Howard.
Finish
The seriously critical job of painting this unique restoration project will be entrusted to Tom, Steve and Mandy of Image Custom Design, Camberley, who have been able to commendably replicate the style and skill that the great Jeff McCann (RiP) introduced to custom bike painting in the 90’s.