Triumph Thunderbird LT Owner's Handbook Manual page 128

Specifications
Transmission
Transmission Type
Clutch Type
Final Drive
Primary Drive Ratio
Gear Ratio:
1st
2nd
3rd
4th
5th
6th
Final Drive Ratio
128
Thunderbird Commander and Thunderbird LT
6 speed, constant mesh with transmission damper
Wet, multi-plate
Toothed belt
1.440:1 (85/59)
2.875:1 (46/16)
1.958:1 (47/24)
1.536:1 (43/28)
1.219:1 (39/32)
1.029:1 (35/34)
0.909:1 (30/33)
2.214:1 (62/28)