• Year of manufacture 
    1921
  • Motorcycle type 
    Street
  • Engine number 
    523 (2435)
  • Lot number 
    240
  • Condition 
    Used
  • Colour  
    Other
  • Location

Description

1921 BSA 4¼hp Model H
Registration no. NX 6423
Frame no. K240
Engine no. 523 (2435)

• Desirable 'all chain' model
• Un-restored condition
• Ideal 'Banbury' bike

Originally established in 1861 as an armaments manufacturer, The Birmingham Small Arms Company switched to making components for the bicycle industry in 1878 following a Government-induced downturn in the arms market. BSA first experimented with powered two-wheelers in 1905 using a standard-type bicycle. This first motorcycle made by BSA used a proprietary engine - probably the Belgian Minerva - clipped to the front down-tube, but it was not until 1910 that the firm introduced a model entirely of its own design and manufacture. Displayed at that year's Olympia Show, the first series-production motorcycle to feature the marque's distinctive green and cream tank colours was a 499cc (3½hp) sidevalve single, built initially with single-speed, belt-drive transmission and later on with a three-speed countershaft gearbox. Well engineered and equally well made, this first BSA proved an enormous success and changed little over the next few years, though for 1912 a two-speed hub gear was available together with an all chain drive model suitable for sidecar work. For 1914 the range was augmented with a 557cc (4¼hp) long-stroke version featuring a strengthened frame and the new three-speed gearbox, which was designated Model K if fitted with chain-cum-belt transmission or Model H with fully enclosed all-chain drive.

BSAs of the early 1920s were essentially developments of pre-war models. The Motor Cycle's celebrated correspondent, Ixion, tested a 4¼hp model in 1920 and wrote: 'I did not know that a single-cylinder could develop so much power. I never unearthed a gradient that could bring her down to first, using that gear only for starting off. And talk about substantial! The BSA is built like a tank and is fundamentally incapable of fracturing anything, whilst she creates the pleasant impression that nothing will ever wear out.'

This delightful un-restored Model H appears substantially complete, retaining the all important primary and final drive chain enclosures. It also carries a tax disc that expired July 1967. The BSA was acquired for the collection in 1993. Accompanying documentation consists of an old-style continuation logbook, 1997 tax disc, old V5 and V5C registration documents.


Bonhams 1793
101 New Bond Street
London
W1S 1SR
United Kingdom
Contact Person Kontaktperson
First name 
Bonhams Collectors’ Car department

Phone 
+44-2074685801
Fax 
+44-2074477401