Rt 225 Gearing

[a-teamlambretta]

Im just building up a motor using an rt225 top end and a Gori 50mm exhaust. What gearbox and sprockets will be best suited. Cheers simon

[dickie]

Which gori 50? The gp50 and the other one, (sport?) are very different pipes. I've got the one I think is called the sport on my 175 and it's very like a bgm v3 whereas the gp50 behaves a bit like an expansion.

Does it have tapered header?

[a-teamlambretta]

Its the one without the tapered down pipe

[rossclark]

I had been running mine on std SX200 gearing 4.8 but was advised it was over geared - I dropped the final ratio to 4.9 by changing the 46 CW to a 47 - do I think that's any better? Not really. It just feels like it's revving a bit harder to get to 65 than it used to. I'm seriously considering putting it back the way it was.

It's supposed to be able to pull taller gearing than that but I guess that might be for the racing snakes among us.

I'd start around 4.8 and see how it suits you / performs. That'd be GP200 box with 19/46 or straight SX/TV on 15/46.

[a-teamlambretta]

Thanks for the info. I will try sx/15/46 and see how it goes.

Cheers simon