Dave, I keep sending to the wrong place so this time I will send separately to you and CR. Yes the Rotrax shop in Shirley Road is closing but they are going to continue building bicycle frames. My old man says it was bikes first and then speedway which was the big earner. 1947 Freddy Prince formed the Rotrax company in a cycle shop in Southampton. It was 1952 that Rotrax started to make their first speedway motorcycle frames. Mike Compton, who was the Workshop foreman, together with the British Oxygen Company, developed a nickel-bronze brazing technique for the frame lugs and "Renolds 531" tubing that was to give the beautiful hand-built frame the strength and qaulity needed for track racing. This method of brazing was later adopted by the aircraft industry on their jet engine frames.
Meanwhile, Alec Jackson (ex-rider) had taken over manafacturing rights of the JAP speedway engine in 1951 and continued to hand build engines and spares for many years afterwards, later still to be taken over by George Greenwood.
The Rotrax frames were first chromed by Blakes of Gosport and then sent on to Alec Jackson's in London for the fitting of the JAP's . Thus the Jackson-Rotrax was formed.
Rotrax were not the only ones to make frames for speedway, my Dad knew them all but his memory is bad now and I can't either, use to tell me as a kid when he took me speedway racing sure he said Butlers and Rensch. Those were the days Wembley (Split Waterman),New Cross, Stamford Bridge, West Ham, Wimbledon and Harringay. Now all gone. If you are boning up on Rotrax try the speedway route.
Thats all for now. Keep those wheels spinning, in your memories if not still on the road. Be lucky Mick Butler Huntingdon UK.