Plunger gearbox reverse and shift on the fly modifications

Back 2012 I started a project to install a reverse chain drive and shift on the fly shifter on my 1997 Rokon Ranger. The reverse modification is documented here in Bob Gallaghers Rokon World message Board. Reverse has been working since August 30th 2012 with one minor shifter issue not related to the reverse drive. I wanted to test drive it a bit to make sure reverse held up before I started on the shift on the fly part of the project. I figure 9 years is long enough so I started looking again at shifters that could be modified to fit. Hodakas and Yamaha scooters use the same design ball shifter as my 1974 Rokon gearbox. Both of their shifters are large and complicated. Vespas use a cross shaped shift selector that works the same as the newer #17 Rokon tang shift selectors. Vespas have a very compact and simple cable operated shift selector that looks much easier to adapt to a Rokon.

This is a 4 speed Vespa shift selector that has a neutral between 1st and 2nd. On the 3 speed Plunger gearbox the neutral will be between reverse and first.