1930 Brough Superior SS100 Alpine Grand Sports

“Rolls-Royce of Motorcycles” is brochure weather. A 1930 Brough Superior SS100 Alpine Grand Sports with a Works Record Card, matching major numbers, and Bentley & Draper sprung frame is a countable object. Bonhams’ Autumn Stafford catalogue places this machine among the 21 JAP-engined SS100s built for 1930 — a production figure you can cite. Alpine Grand Sports specification (lower compression touring brief, fly-screen and toolbox language in the model’s period identity) plus B&D springing separates it from a generic rigid SS100 story.

Identity as published: frame S. 1015, tank 2099, engine JTO/W 84303/CS, gearbox 169940. Catalog diligence notes matching registration/frame/engine/tank with a non-original gearbox. The Copy Works Record Card shows dispatch with a Cruiser sidecar to Sears Garage. Later public trail: Shoosmith’s Gangbridge Collection auction 1989, Eddy Shah ownership oriented around the MY 2654 plate, Vaughan Gaskell’s 1998 recognition and purchase, then a Dave Clark restoration from 1999 into the early 2000s. Since Gaskell’s death in 2019 the SS100 has remained in family hands. That is collector-provenance continuity, not a factory championship diary.

On Brooklands, be careful. The catalogue says the machine is reputed to have raced there (foot-change suggestion) and that the claim has never been conclusively verified. So treat “reputed Brooklands” as an unproven story, not provenance. The rarity score rests on the verified works paperwork and matching major numbers; the unverified track history counts for little.

Score 87 — Rare-enough. One of 21 JAP SS100s for 1930, in Alpine Grand Sports specification with the B&D sprung frame. The collector and restoration trail is strong, but the provenance score is held back because Brooklands remains unverified. Documentation is the Works Record Card plus the Bonhams file. Sorted 1930 JAP SS100 AGS machines come to market infrequently, and the condition reflects the Clark restoration rather than unrestored originality.

Auction: Bonhams Autumn Stafford Sale, Lot 328, 11 October 2026.

Watcher’s checklist

1. Match frame S. 1015 / engine JTO/W 84303/CS / tank 2099 to the Works Record Card copies.
2. Budget for the catalogued non-original gearbox.
3. Separate verified ownership trail from unverified Brooklands reputation.
4. Review Dave Clark restoration notes and what was replaced vs retained.
5. Confirm UK registration MY 2654 recovery paperwork if plate continuity matters to you.
6. Re-check Bonhams Lot 328 status before you act.