Low Numbers, High Collectability: The BSA A70L 750 Lightning

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Photo By Stephen Clark
Brian St. John of Legend Cycle in Idaho Falls, Idaho.

A70L 750 Lightnings are highly collectible — not surprising given their rarity. And as they were intended for flat track duty, surviving 750s with their engines in place in their original frames can probably be numbered in the dozens. That makes putting a price on one a bit tricky, as their low numbers mean they don’t change hands very often.

If you’re planning to buy a BSA A70L 750 Lightning, it’s important to verify the bike’s provenance. Verification is tricky, however, because outside of the telltale “750” on the side covers and different engine numbers, there are no external differences from the A65L. Frustrating the issue, there apparently is evidence that some A70s may even have been stamped with A65 engine numbers.

Brian St. John of Legend Cycle, the Idaho-based shop that restored our feature bike, says the bike’s A65 origins made the restoration fairly easy, except for sourcing new pistons. “I was afraid we were going to have to get some pistons made, but I finally found a pair through Baxter,” Brian says. The side cover decals were easy to replicate, but it took a little longer to duplicate the factory emission/VIN decal fixed to the frame plate on the right side of the steering head. “It’s a clear decal with white lettering,” Brian says. “I had to hunt down the right font and spacing and get it just right, working with pictures.” Brian photographed every detail of the bike — including the decal — before and during the restoration.

A 10-year veteran of the Air Force, where he specialized in aircraft structural maintenance, fabrication and repair, and the son of a former Triumph dealer (“Triumphs are what I started on when I was 13”), Brian’s uniquely qualified to perform the metallurgical surgery that often accompanies vintage bike restoration, including repairing the A70’s broken primary cover, which was shattered when the bike was hit by a car in 1978. “Chunks of aluminum got bound up in the sprocket and the engine wouldn’t turn over,” Brian says.

Learn more about the BSA A70L 750 Lightning in New Rules 1971 BSA A70L 750 Lightning.

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