A bit of Vincent streamliner transmission history is in order. When I first built the liner, I used a standard four speed Vincent transmission, and employed a mechanical shifter. Next came a Surtees five speed transmission, which employed an air shifter. Next I discarded the transmission and utilized the transmission cavity to support a jackshaft, which went back to a modified Muncie transmission. Originally the transmission was built for the Easy Rider machine. Bob George, the principle person behind the design of the Muncie transmission, had reversed the input, Dave Campos told me that he believed this was the reason that the transmission never shifted well. The transmission wound up in Don Vesco's shop. I had been enquiring around for a whole Muncie M21 transmission to modify for use in the liner, using second, third, and fourth. Don said if I could use the Bob George transmission he would send it on to me, and he did. Had to modify the transmission quite a bit to make it work for the liner. I changed the input of the transmission, made outboard carrier bearings for the input and output shafts, and built an air actuated mechanical shifter. The transmission gears weren't the famed "rock crusher" type. They had more of a helical angle than the rock crusher gears. Sometimes the transmission worked well, other times it didn't, due to shift linkage adjustment. While in the pits one year the engines running at rather a high rpm, the transmission was engaged inadvertantly. This blew all the teeth off the gears in the transmission. We did continue to make a couple of runs by locking the transmission in high gear. When I got the bike back to Wichita, I located a firm in Chicago that dealt with the Muncie transmission and was having their gears made in Italy. I bought the gears I needed, changed the ratios a bit, also changed it to a 'rock crusher'. This transmission I've utilized up until this year. This year a one off transmission is being built as we speak by a group of four Germans. More on that later.
Max