VS
The 1970 BSA A65 Thunderbolt and 1971 BSA B50MX represent two chapters in BSA's storied history.
The 1970 BSA A65 Thunderbolt from United Kingdom was powered by a 654cc OHV twin producing 46hp at 6800rpm. Weighing 178.0kg (392 lbs) and with a seat height of 790mm, it was aimed at standard riders.
The 1971 BSA B50MX by contrast offered 499cc of OHV single power, delivering 34hp at 6000rpm. Tipping the scales at 149.0kg (328 lbs) with a top speed of 140km/h (87 mph), it offered a distinct riding experience. 1970s bikes from the Japanese superbike revolution are increasingly sought after. Clean, original examples have seen significant value appreciation.
The 1970 BSA A65 Thunderbolt from United Kingdom was powered by a 654cc OHV twin producing 46hp at 6800rpm. Weighing 178.0kg (392 lbs) and with a seat height of 790mm, it was aimed at standard riders.
The 1971 BSA B50MX by contrast offered 499cc of OHV single power, delivering 34hp at 6000rpm. Tipping the scales at 149.0kg (328 lbs) with a top speed of 140km/h (87 mph), it offered a distinct riding experience. 1970s bikes from the Japanese superbike revolution are increasingly sought after. Clean, original examples have seen significant value appreciation.
Specifications Comparison
| 1970 BSA A65 Thunderbolt | 1971 BSA B50MX | |
|---|---|---|
| Displacement | 654 cc | 499 cc |
| Power | 46 hp | 34 hp |
| Torque | 50.0 Nm | 38.0 Nm |
| Cylinders | 2 | 1 |
| Top Speed | 170 km/h | 140 km/h |
| Quarter Mile | — | — |
| Dry Weight | 178.0 kg | 149.0 kg |
| Wet Weight | 191.0 kg | 161.0 kg |
| Seat Height | 790 mm | 830 mm |
| Wheelbase | 1400 mm | 1380 mm |
| Fuel Capacity | 14.0 L | 10.0 L |
| Gears | 4 -speed | 4 -speed |
The Verdict
Comparing these two BSA machines reveals the brand's evolution. The 1970 BSA A65 Thunderbolt laid the groundwork with 46hp, while the later 1971 BSA B50MX pushed output to 34hp. Both share equal collector appeal at 5/10. Either way, both are worthy additions to any BSA collection.
About the 1970 BSA A65 Thunderbolt
A standard motorcycle from 1970, the 1970 BSA A65 Thunderbolt delivers 46hp from its 654cc OHV twin engine.
Full 1970 BSA A65 Thunderbolt Profile →About the 1971 BSA B50MX
Introduced in 1971, the 1971 BSA B50MX features a 499cc OHV single engine producing 34hp, establishing itself as a notable dual-sport.
Full 1971 BSA B50MX Profile →