BSA A70 Lightning Information and Register


BSA A70 Lightning

The BSA A70 Lightning was a 750cc equivalent of the BSA A65 produced for the US market for flat track racing. Raced by stars of the time such as Dick Mann. They were also known as a ‘Lightning 75’. Whilst the bike used the same chassis as the A65 there were the following differences:

  • Standard 930/78+9 carbs but fitted with larger 250 mainjets
  • Increased Stroke (75mm x 85mm)
  • Increased Compression Ratio (9.5:1)
  • Crankcases
  • Crankshaft
  • Crankshaft Sludge Trap
  • Connecting Rods
  • Big End Shells
  • Flywheel and Bolts
  • Timing Side Bush
  • Oil Pump Drive Pinion Washer
  • Crankshaft Pinion
  • Crankshaft Thrust Washer
  • Crankshaft Shims
  • Oil-Pressure Release Valve
  • Pistons and Rings

Colour Specification
Frame and Chassis    All Black except side panels and petrol tank finished in Etruscan Bronze with white bottom and fluorescent linings (currently available from BBB).

Only 200 A70Ls were produced, 102 in June, 64 in July and 36 in August, See the production records below. These can be identified by the engine frame numbers; G June, J August and H July. Out of the 202 A70’s produced, it is believed that most were originally shipped to Baltimore and approximately 23 to California. Although they were released as 1972 models, they are stamped as 1971.

East Coast Distributor
The Birmingham Small Arms Company Inc
BSA Sales Division
PO Box 6790
Maryland 21204
West Coast Distributor
The Birmingham Small Arms Company Inc
BSA Sales Division
PO Box 337
California 91010

For Magazine articles on the BSA A70 Lightning, See;
Classic Bike October 1995 (Features our own A70L)
Classic Bike September 2008

BSA A70 Photo Gallery

BSA A70 Lightning Seattle

Dick Mann with Alastair McQuaids A70 Trackmaster at Beezumph Rally

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Current Bikes in the register

Engine/Frame Number Location Current State Comments
GE01022 Leicester, UK Being Restored Imported from Randy Baxter in USA
GEO1025 Varberg, Sweden Fully Restored Dove Grey frame, never resprayed
GEO1027 Philadelphia Pennsylvania, USA Unrestored Rider in great condition
GE01030 Florida, USA Being Restored  
GE01031 Vale of Glamorgan, Wales Basket Case Cases and motor parts only
GE01035 Essex, UK Being Restored Chopperized, Currently undergoing restoration
GE01041 Springville NY, USA Fully Restored NY License plate “BZRGZR”. Many updated parts, not a “restoration.” Daily rider since 1973. Acquired from original owner, frame black, tank & sidecovers dark blue. About 40,000miles as of 2010, but expect many more in the near future, as my commute has grown longer as of 2010. I video recorded my last full rebuild (about six hours’ worth) in 2009 on hi-def (blue-ray). As I get older, I want to remember how it was done…
GE01046 Ohio, USA All Original  
GE01054 Ashby de la Zouch, UK Fully Restored As featured in Classic Bike Magazine Oct ’95
GE01055 New York, USA Unrestored and Complete  
GE01057 West Midlands, UK Being Restored  
GE01069 Oakland California, USA Fully Restored Bought about 5 yrs ago for $800 had Rabers in San Jose rebuild motor got from orig. owner who flat tracked raced, then turned it into a bobber in 1972
GE01070 North Olmsted, Ohio, USA Fully Restored All Stock except paint, 12,700 miles
GE01079 Wakefield, USA Original, Unrestored  
GE01092 Atlanta, GA, USA All Original  
GE01097 Rock Valley, Iowa Off the Road Barn find fresh rebuilt engine in an old basket case 68 frame. An older gent lost interest in the project after losing a friend and parked the bike. The gentleman tells me the engine was originally built by Cheney of Sioux Falls, SD. Until today I knew nothing of the A70L significance.
GE01101 Melbourne, Australia All Original The bike was imported to Australia from USA by a Harley importer circa 1982. It is mostly original apart from seat recover, tank and side covers painted. It is black frame with dove grey schocks. It was painted blue when I obtained it and had a NC license plate. After getting details of previous owners from NC DMV I wrote to the original owner who advised it was orange when purchased new.
JE01173 Vale of Glamorgan, Wales Fully Restored Flat track racer with known history
JE01185 California, USA Fully Restored Restored in 1980s, currently in storage.
JE01194 Petaluma,California Being Restored May put motor in 71 lightning frame.
JE01203 Dettenheim, Germany Fully Restored Donelson Bike from USA. A70 Engine in a A65 Spitfire Frame. Called Spitfire MK5 750. MK4 Lookalike.
HE00163 El Cajon, California, USA Fully Restored Ex-racebike, flattrack miler. It has an early Ray Hensly-Trackmaster chassis, with Ceriani / Girling suspension & Barnes wheels. For the motor it has an ARD Magneto, Sifton Cams & headwork, ACK clutch cover, & one off magnesium Mikuni carbs that are rare.
HE01121 Middletown, OHIO, USA Fully Restored Very Nicely Done, not molested
HE01122 Northampton, UK Fully Restored Imported from US in bits with broken conrod. Due to be featured in Classic Bike Magazine
HE01136 Atlanta, GA, USA Basket Case Currently a rolling chassis only.
HE01139 Tonsberg, Norway Off the Road Dirt Track seat/tank
HE01142 Pontefract, UK Fully Restored  
HE01158 Mass, USA Frame Only  
HE01159 Florida, USA All Original  
HE01161 Seattle, USA Fully Restored On Disply in office, Pictured above with red tank
HE01166 Cross Lake MN, USA Being Restored  
HE01168 Nebraska, USA Being Restored Looking forward to riding it as I hear they are quick!!!!  Have been doing BSAs since the early 70s and even had a goldie at one time
HE01170 Christchurch, New Zealand Basket Case Just started this project having won an auction, 90% complete
HE01208 Mid Wales   White & Red
P50 004 West Midlands, UK Basket Case Prototype Number Four

BSA A70 Production Records

Number Produced Date
1 12/06/1971
64 25/06/1971
38 02/07/1971
63 09/07/1971
21 13/08/1971
15 20/08/1971


A70 Service Bulletin