Offered from The Forshaw Speedway Collection, c.1951 Excelsior-JAP 500cc Mk IV Speedway Racing Motorcycle

Engine no. JOS/I 81792

• The epitome of the speedway machine of its day
• Considerably lighter than the preceding models
• All welded construction with very light weight lugs

The Mk I (Lot 511) and Mk II (Lot 512) Excelsiors provided machines for the early post war period. A pre-war design, the remaining batch of Mk I frames ordered by Max Grosskreutz from Excelsior early in 1939 was now readily available for 1946 - the first speedway season since 1939. The Mk II was an updated robust but still quite heavy machine leaving the requirement for something more refined for the leading riders. There is some confusion as to whether there was a Mk III and if so how it evolved but from a report from early 1951 it is made clear that the current machine for the leading riders was the Mk IV. The Mk IV followed the path of the Mk II but was designed to be considerably lighter in the trend of recent frame construction, the frame using a light gauge aircraft specification Molybdenum tube. This was used for the front forks as well which now had smaller crowns with aluminium bushes as opposed to bronze bushes in the earlier frames. The frame was an all welded construction with very light weight lugs at the headstock and for the saddle tube position. The engine was mounted a little further back than the Mk II to achieve the required weight distribution. With these developments the Mk IV weighed in at under 200lbs a saving of a full 30lbs. The entire frame was chrome plated with the Excelsior signature bright red fuel tank.

The Excelsior was the epitome of the speedway machine of the day. The riders in black leathers on this spectacular machine gleaming under the stadium lights. By 1951 Alec Jackson had the concession for Excelsior and had also taken over the manufacturer of the JAP speedway engine from the Prestwich factory. There is no known history with this Mk IV Excelsior but is it a further example of Richard Forshaw's discerning collecting targets. There are accompanying photographs and Mk IV literature including adverts.
The mechanical condition is not known and therefore we recommend re-commissioning and/or restoration to a greater or lesser extent.
Key not required