LCGB Forums

I am running a pacemaker box with a 16 front sprocket on the rt195 kit.28mm dellorto,42 af clubman.toying with the idea of trying a 17 tooth sprocket.if I remember right this makes the final drive about 4.9 ish.Is anyone running similar?if so ,how does it perform.i don't ride 2 up,and and I am not trying to improve top speed but at 5.3 it is very revvy,so I feel it should handle it ok without losing the acceleration .any thoughts please

I'm running that gearing with an MB clubman and a 30mm delly, pulls it no problem.

I originally ran my RT200 (110/60 crank) with 28 delly/AF clubman combo and it was fine. I run a standard Li150 box so 16 tooth sprocket is giving me 4.9 at the moment, as you say on the pacemaker you will get the same with a 17 tooth sprocket. Having recently changed exhaust to a JL3 I'm going to try the 17 tooth sprocket to give me 4.6 as it's now seems to be revving on more.

http://beedspeed.com/html-pages/LambrettaGearBoxOverallGearRatioChart.htm

Bluebob, mine was almost identical to you. My original build and my second build after a failed ring peg were at a final ration of 5.21, a 15 tooth standard front sprocket, 46 tooth clutch sprocket and standard Italian Li150 box, with an MB clubman, and as you say its a very revvy engine in that config. Just looked at the gearbox calculator online and yours is at 5.3, so its going to be even more revvy than mine was.

Just built with my meteor piston and put a 16 tooth front sprocket to come down to 4.89, and its much better and could probably even do one more step to a 17 tooth. You will come down to 4.98 with a 17 tooth, and 4.70 with an 18 tooth.

I'm going to leave as is for now as its nice to have the revs there when you want them rather than coming down another stage, but I would definitely put in a 17 tooth in yours.

Google 'Lambretta Gearbox calculator', it comes up on a scooter help webpage, you just plug in your settings and it shows the ratios and speeds in each gear at different RPM.

that's settled then!17 it is.thanks for the replies

Paul_from_Thornbury wrote:Bluebob, mine was almost identical to you. My original build and my second build after a failed ring peg were at a final ration of 5.21, a 15 tooth standard front sprocket, 46 tooth clutch sprocket and standard Italian Li150 box, with an MB clubman, and as you say its a very revvy engine in that config. Just looked at the gearbox calculator online and yours is at 5.3, so its going to be even more revvy than mine was.

Just built with my meteor piston and put a 16 tooth front sprocket to come down to 4.89, and its much better and could probably even do one more step to a 17 tooth. You will come down to 4.98 with a 17 tooth, and 4.70 with an 18 tooth.

I'm going to leave as is for now as its nice to have the revs there when you want them rather than coming down another stage, but I would definitely put in a 17 tooth in yours.

Google 'Lambretta Gearbox calculator', it comes up on a scooter help webpage, you just plug in your settings and it shows the ratios and speeds in each gear at different RPM.

Exactly the same, runs great