BSA Thunderbolt
British motorcycle manufactured between 1964 and 1972
The BSA Thunderbolt was a British motorcycle made by BSA at their factory in Armoury Road in Small Heath, Birmingham between 1962 and 1972. Fitted with a single carburettor it was capable of over 100 mph (160 km/h).
Development
The BSA Thunderbolt was designed as a touring motorcycle. A traditional air cooled 650 cc twin cylinder with a single large bore Amal Monobloc carburettor, it did not suffer from the same level of vibration as earlier BSA twins and could comfortably cruise at 70 mph (110 km/h). and reached over 100 mph (160 km/h). in road tests.
The BSA development team decided to keep costs down by re-using the well proven single sided front brake from the BSA Gold Star and the same full race camshaft as the BSA Lightning. Fitted with 12 volt electrics, a Zener diode voltage regulator and twin coil ignition, the Thunderbolt sold well in the important US import market and with the 3.5-imperial-gallon (16 L; 4.2 US gal) fuel tank gave a range of 210 miles (340 km).
From 1968 the Thunderbolt benefited from a number of minor improvements including a longer kick start to make starting easier and metal tank badges to replace the earlier plastic ones, which had a tendency to crack. An Amal Concentric carburettor dealt with the problems of fuel flooding experienced with the earlier monobloc carburettor, by having the float bowl arranged centrally around (concentric with, hence the name) the main jet to remove the sensitivity to fuel surge inherent in all the earlier designs.
“BSA Thunderbolt” enters the record as british motorcycle manufactured between 1964 and 1972. Crown Archives preserves that source wording while asking what Thunderbolt, British and motorcycle can confirm, complicate or overturn.
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“BSA Thunderbolt” is worth following because a concise public description often conceals a longer documentary argument. Here, Thunderbolt, British and motorcycle provides the most credible route into that argument.
The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Apr 29, 2021. The linked authority identifier is Q4836562. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1962, 1972 and 1968.
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This entry incorporates text from “BSA Thunderbolt” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.