Several years ago I built a bike I called "The White Horse", and sold it to a friend of mine. Recently he decided he would like a 5 speed with the new style electric starter setup, rather than the Hitachi style I built it with. He also had bought himself a 5 speed somewhere, so We decided to put it in. The thing is , a true 5 speed doesn't fit in a true 4 speed frame. Now of course you can buy a Baker "6 in a 4" style transmission, but you would be stuck using either the Tech Cycle electric starter kit (which is a pain in the ass), or the Hitachi system again, but not a true new style starter. what do we do?
I noticed that I needed to notch the rear of the electric starter mount, and the rear of the motor plate to clear the swingarm hub. This was done on the mill and with hand tools. This wasn't enough to make it fit, so i also had to notch the seat tube just in front of the trans plate. I gusseted it with 3/16" steel plate.
Now the 4 speed trans plate had to be swapped for the 5 speed one, except 2 of the 4 mounts on the frame are different. No problem; remove, build, replace.
Now the trans was in, but what about the primary? The distance between the sprocket shaft of the engine and the trans main shaft is now shorter than stock! I thought about using an FXR style belt, but it was too short. Luckily I have friends like the guys at Bandit Machine Works in PA. I told them about my problem, and before you can say "fuck Taiwan" a complete primary drive came in the mail- made custom to my new dimensions.
Here it is mocked up. Yes I know the coil is hanging there...
Oh yeah, I forgot to mention that the entire trans had to be about a half-inch further towards the carb side of the bike. This was because I re-used the right two trans plate mounts, allowing me to re-use the 5th mount. I only re-built the left two mounts. Anyway, no big deal, I simply milled the alternator cover down the appropriate amount, moving the front pulley inward a half-inch, then used a half-inch offset final drive sprocket (putting the chain back it the original place).
It also features a Baker hydraulic clutch cover. Just remember, at Efab "everything fits anything".