Ending Wed, 16th Feb 2022 12:35:00

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  Lot 109

c.1955 BSA B31 Trials Bike
Unfinished Project

Sold for £2,760

(including buyers premium)

Lot details

Registration No: UN-Reg
Frame No: CB31 9009
Engine No: BB31 18122
CC: 350
MOT: Exempt
Estimate: £1,500 - £2,500

Location: Cheshire

  • Part of an enthusiast private collection for many years.
  • B31 crankcases only, no crank, timing gears, clutch or primary drive
  • Alloy barrel, no piston, and alloy head with valves
  • Fitted with 'TRI' stamped gearbox and 'Lucas Racing' badged mag
  • Alloy mudguards and Catalina style small fuel tank
  • Unfinished pre 65 trials project, no documents

The Birmingham Small Arms Company Limited (BSA) was established in the Small Heath area of Birmingham in 1861 and, as the name suggests, BSA manufactured weapons. Around the turn of the century they started making bicycles and progressed onto motorcycles a few years later. BSA went on to become one of the world's largest producers of motorcycles up until its demise in the early 1970s.

This very interesting unfinished project is based around a circa 1955 B31 frame fitted with an all alloy top end. The motorcycle formed part of an enthusiast's private collection of mainly British off road bikes and it has a 'Lucas Racing' badged mag and the gearbox cover is stamped 'TRI'. The crankcases are standard B31 with no crank, piston, timing gears, primary drive or clutch present, the top end is alloy with valves in the head.

The chassis appears to be more complete with a bespoke central oil tank, upswept exhaust with alloy silencer, with what looks to be a Gold Star Catalina style fuel tank, a single seat and alloy mudguards. There are lots of handmade stainless steel and alloy brackets and stays fitted by the engineer owner. Obviously, a lot of work still needed to finish but there are some rare and expensive parts already in place and it is a very good starting point for a pre 65 trials or classic green lane bike. No documents are included with this bike.

For more information, please contact:
Ian Cunningham
07415 871189


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