Description
This motorcycle is Lot 347 to be auctioned by Bonhams at The Autumn Stafford Sale (The Classic Motorcycle Mechanics Show) on October 10th – 11th, please see the Bonhams Motorcycles Website for full details.
Auction Timings:
Lots 201 - 407 are to be sold from 11AM local time on Sunday 11th October 2026.
Public Viewing:
Available 10th & 11th October 2026 from 09:00 until 17:00, at The Staffordshire County Showground (The Classic Motorcycle Mechanics Show).
Lot 347
Property of a deceased's estate
1931 Sunbeam 598cc Lion 'Longstroke' Motorcycle Combination
Registration no. OV 3608
Frame no. D 10472
Engine no. JA1015
The first Sunbeam motorcycle - a 350cc side-valve single - left the Wolverhampton premises of John Marston, hitherto a manufacturer of finest quality enamelled goods, bicycles and - latterly - cars, in 1912. Like Marstons other products, his motorcycles soon established a reputation for sound construction and exemplary finish. Sunbeams famous longstroke sidevalve engine first appeared at the 1921 French Grand Prix, scoring a debut win in the hands of Alec Bennett, and in road-going form this remarkable engine remained in production right up until WW2. A 492cc version of it powered the new-for-1931 Model 6 Lion. Introduced in the summer of 1930, this revamped Lion replaced the old Model 6 and featured the innovations - for Sunbeam - of a chromium-plated fuel tank and Webb-pattern girder forks.
A new-for-1932 '600' Lion was launched at the November 1931 Olympia Show where Sunbeam unveiled their 1932 range. However, Marston's had first advertised the availability of a '600' Lion in July 1931. This was quite distinct from the 1932 Olympia model; it was simply the 1931 500 Lion with the new, detachable-head, 600cc sidevalve motor fitted. It is described in the 23rd July 1931 issue of The Motor Cycle. Cycle parts included the 1931-only, black-panelled, chrome tank; the 1931-only Webb fork design; the deeper-valanced front mudguard; and the Sunbeam three-speed gearbox.
The machine offered here appears to be one of the few mid-1931 models produced before the debut of the true 1932 model at Olympia in November '31. Almost certainly attached to the machine from new, the sidecar appears to be Watsonian's top-of-the range Monarch model.
On file is a thorough and most detailed explanation of this particular Lion's distinctive characteristics, produced by the Marston Sunbeam Club and marking it out as extremely rare, which is a 'must read' for prospective purchasers. This document deals with apparent discrepancies concerning the frame and engine numbers, and concludes that 'this is a genuine - and extremely rare - early 600 sidevalve from 1931'.
Offered from a deceased's estate following a house clearance, this 'barn find' Sunbeam combination lacks any form of documentation and its history is entirely unknown, though the registration number's OV prefix indicates that it was originally issued in Birmingham from around August to September 1931. According to the accompanying HPI report, the machine was previously registered overseas and was acquired by the late owner on 21st March 1984. The VRN appears on the HPI/ DVLA databases. Prospective purchasers must therefore satisfy themselves with regard to the validity of the VRN and will be responsible for applying to the DVLA for a replacement V5C using a V62 form.
Offered as a potentially most rewarding restoration project, the combination requires extensive refurbishment and is sold strictly as viewed (it should be noted that the engine does not turn over). Following a period of inactivity, this motorcycle will require recommissioning and/ or restoration to a greater or lesser extent before returning to the road and thus is sold strictly as viewed. Prospective purchasers should satisfy themselves with regard to this motorcycle's completeness, history, authenticity, originality and mechanical condition prior to bidding. Bonhams would like to thank the Marston Sunbeam Club for their kind assistance in preparing this description.
£1, 000 - 2, 000
All lots are sold ‘as is/ where is’ and Bidders must satisfy themselves as to the provenance, condition, age, completeness, mileage, engine capacity and originality prior to bidding. Visit the Bonhams Motorcycles website for all pertinent auction information.
