for Vespa 125 GT/ GTR/ Super/ TS/ 150 GL/ Sprint/ V/ Super/ 160 GS/ 180 SS/ 180 Rally/ P80-150X/ PX80-150 E/ Lusso/ ’98/ MY/ ’11/ Cosa 125-150/ T5
with repair kit primary DRT
Product description
The DRT Primary Gear with 65 teeth was developed to lengthen transmissions of large frame Vespas built from 1960 on up to 125/150 cc PX models. The DRT gear has a larger diameter than the PX200 primary 65, and matches the original. It’s a perfect fit for all clutch gears with 20/21/22 teeth, though not with the PX200 clutch with 23 teeth. Tried and tested: the combination of longer 4th gear w/ 33 teeth and short primary (65-20) or 4th gear DRT 36 teeth with a 21 or 22 toothed clutch gear. Feasible Transmission Ratio PX/T5/Cosa:

Oldies:
65-22=2.95
65-21=3.10
65-20=3.25

22x65x25x45=5.30
37-21=5.20
37-21=5.45
37-20=5.72

22x65x25x44=5.20
36-21=5.06
36-21=5.30
36-20=5.57

20x65x27x43=5.17
35-21=4.92
35-21=5.16
35-20=5.40

20x65x27x42=5.05 34-21=4.80
34-21=5.00
34-20=5.26
33-21=4.65
33-21=4.86
33-20=5.10 OEM numbers (for comparisons):
8000000028792 – a02879 (previous: PRk VelPX 229 z6 (DRT)