SP gearbox wanted or SP engine

[Davw]

My sp engine c/w cams, sp loom, Mitsubishi box (the electrics came from MM couple of years back) could be available as a package if good offer.

Engine is Roger M tuned and the bike did the manx this year. I wont be doing the manx again on a 400 (back pain only just subsided!!!) so pm me if interested and cash always talks!!

[Scoober]

Can the 'Taller' first gear from a SP gearbox be added to a standard 'Normal' non-SP gearbox?

When racing - I am pulling Wheelies off the start that are causing issues.

The gearing for the rest of the track are very good, so just looking to add a taller 1st gear.

Looking forward to your thoughts.

[Max4music]

I don't believe it can. Its a question I asked years ago and a fella explained why not, but I never really understood his answer, I just took his word you cant, and as Ive never heard of anyone doing, I guess this is true. You could have a transmission made from scratch by someone like Nova, who do loads for race teams, but I think you are talking £2000 plus. The tall 1st gear defo helps reduce wheelies but it takes quite a knack to launch without bogging down, especially on tracks where your bike is geared high anyway such as Thruxton.

[Miles]

Sorry to jump on this thread but out of interest does anyone know if it’s possible to identify an SP gearbox on the bench?

I have one and have been assured it’s an SP gearbox but would just like to confirm