Vespa 125 GT GTR Super TS Sprint Rally PX80-200 PE Lusso T5 Cosa KR AUTOMATION CNC Type Gearbox Kit

for Vespa 125 GT 2°/GTR/Super 2°/TS/150 Sprint 2°/V/Super 2°/Rally/PX80-200/PE/Lusso/T5/Cosa

input shaft 12-13-17-21 teeth, gear cogs 57-42-38-35 teeth

CNC machined gear cogs, from Automation, for Vespa Largeframe models.

Vespa Largeframe engines are becoming ever more powerful. The increase in extreme tuning measures exposes the flanks of the cog teeth to levels of performance that were hardly considerable at the time of their introduction.

Reduced profile displacement.
Surface tempered gear cogs.
25% higher solidity in third gear.

An increasing number of tuning firms are currently producing aftermarket gearbox parts for the Vespa Largeframe models. KR Automation have taken a more detailed and involved approach to the perfection of these essential components. Due to reduced profile displacement, the solidity of the cogs has been noticeably improved.

Gear ratios

1st gear: 12:56; 2% taller; 2nd gear: 11.34; 4.5% taller; 3rd gear: 17.37; 2.7% taller; 4th gear: 19:31; 2.2% taller; 25% higher solidity in third gear.

When compared to the OE transmission the following increases in solidity have been achieved: 1st gear: +26%; 2nd gear: +29%; 3rd gear: +25%; 4th gear: +38%.

With the fourth selected and the motor running at 8000 rpm fitted with a 3.50/10” tyre, the scooter should be travelling at 136.1 kph.

Please note: It is especially important that during the installation of the new cogs the axial mechanical play be adjusted to 2-4/10mm clearance.

Background: The contact surface of these cogs is larger than the original types, reducing the tilt. If the mechanical play is reduced too much, greater friction is sometimes caused and the scooter already pushes forward with no gear selected.

Technical details

CNC turned
CNC milled
CNC ground gears
0,9 mm hardened
Two-piece input shaft
Gearbox surface compressed

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