Thought I might kick off the new section!
Has anyone experience using RGM's close ratio gearset, especially in a laydown box
i've no real experience with it but i thought about the close ratio gears for my commando 850. i calculated the thrust ratio's for both (original and close ratio) and for road use it is better to stick to original in my opinion .
the close ratio gears thightens up 2nd 3rd and4th keeps the gap between 1st and 2nd . first becomes heavier meaning more use of the clutch.
as mentioned before this is for commando i don't know if gear ratio's are the same for the laydown box
Probably not advisable. The AMC box (for which the RGM gears are intended) has the end of the mainshaft secured by a nut under the clutch operating mechanismon the right hand side bearing which stops the mainshaft shifting sidewayswhen the clutch is operated. The laydown boxmainshaft is not secured andrelies on a bronze thrust washer between third and fourth gear which abuts against a hardened steel washer inset into the fourth gear. This prevents the splines on the mainshaft grinding away the rollers in the laydown box's 4th gear. Without the thrust washer set up, each time the clutch is operated, it would probably eventuallyresult in the destruction of the needle rollers in the RGM 4th gear, the splines on the mainshaft and probably damagethe 4th gear as well .Without the hardened steel washer the bronze thrust washer wouldwear out pretty quick.
Someone out there may have done it with a bit of machining and a needle roller thrust washer bearing (Ken McIntosh does these) - if they have I'd like to know!
The mainshaft 1st gear would also have to be modified.
The reason I asked is because having done this and overcome various difficulties, as mentioned above, I wondered if anyone else had done the same thing, and how they got on My gearbox is working well now but not used in anger yet till rest of bike finished
The engine is a dommi 88, well tuned, and I wanted less gap between 1st and 2nd I think the Commando box has a smaller gap here and with all that extra torque the mod is unnecessary as Richard says