Scooterotica

thinking of trying a 14 tooth sprocket with my sx 200 gearbox,currently running a 15 tooth,with rapido 230 mb reed valve,pm25 exhaust,trouble is i have to thrash the knackers off it in 3rd to catch the power band in 4th,i am not hitting power band till speedo says 60, but once there will sit at 70 no problem,could do with hitting the power band around 53/ 55 ish for more normal riding,
question is what crownwheel chain combo will work,avoiding stretched chains,half links etc,cheers all.

The PM is a revvy pipe, might be worth trying something like a JL3 or Franspeed tourer or even a clubman if you can borrow one to see if that makes a difference before changing the gearing.

Try a 47t rear sprocket with your 15t front. you might get away with using your 80 link chain or you may need an 81 link.

just seen on the chain and sprocket section that a 14 /47 will work with a 80 link chain which i should have lying around somewhereshould give me 5.2 against 4.9 previous final drive ratio
,quite like the revvy pm,can get a sprocket for a tenner on ebay so worth a try before lashing out on a new pipe or gearbox,cheers all.

I hope that you have a top notch clutch as the smaller you go on the front sprocket, the more power the clutch has to cope with (why Innocenti changed to 18/47 on the GP200 but could then fit softer springs than the TV175/TV200/SX200 had with the 15 tooth front). Going to 14 tooth means that your clutch will have one heck of a job to do.

Adam

just running a 4 plate indian with stronger springs,the power comes in pretty hard in 3rd and the clutch seemed ok,but i know what you mean going smaller on the front,why is nothing straight forward in the lammy world