Honda TRX680FA Owner's Manual page 246

Specifications
Power Transmission
primary reduction
secondary reduction
final reduction
transmission ratio
final drive
Chassis & Suspension
caster
trail
tire size, front
tire size, rear
tire pressure,
front & rear (cold)
Technical Information
238
forward
reverse
front
rear
1st
2nd
3rd
reverse
1.6 °
0.08 in (2.1 mm)
AT25
DUNLOP KT511
AT25
DUNLOP KT515
front
3.6 psi (25.0 kPa)
rear
3.6 psi (25.0 kPa)
1.333
2.000
2.375
3.231
3.154
2.053
1.375
0.933
2.138
shaft
× ★★
8R12
× 10R12 ★★