Smallframe gearing for M1lr

Schaltroller / Classic Motoscooters Vespa Smallframe
1

Hi all,  I need to buy a 1st and 3rd gear for the smallframe i'm building.  Its a Quattrini m1lr, 54 stroke w/110 Aprilia rod, m3x3 pipe, tm 32.  I expect power to be around 22hp.  I've already got a DRT 2nd (52), and the Zirri short 4th kit with aux shaft (49) but i still need 1st/3rd cogs.  I am thinking DRT long 1st (55) ref 40431710, and DRT short 3rd (51) ref 40431630, do theese gears look like a good choice.  My primary gearing is straight cut 27/69, but I intend to use 24/69 for quicker accelaration. My tire size is 3.50-10

2

good choice for the quattrini

3

hello,

 

I would keep the original 1st in your set up keep the 3rd and 4th that you have and go 25/69 or even a little shorter.

3.10 tires already give you 10% longer ratio.