JT Sprockets

Online Catalogue

Yamaha YZ125 L,M,N

1999 to 2001

Front Sprocket

Steel Front Sprocket

Part Number: JTF564

Teeth: 13

Available Sizes: 12, 13, 14, 15

Rear Sprocket

Lightweight Self-Cleaning Rear Sprocket

Part Number: JTR251SC

Teeth: 48

Available Sizes: 48, 49, 50, 51

Steel Rear Sprocket

Part Number: JTR251

Teeth: 48

Available Sizes: 38, 46, 47, 48, 49, 50

Racelite Aluminium Rear Race Sprocket

Part Number: JTA251BLK

Teeth: 48

Available Sizes: 48, 49, 50, 51, 52

Drive Chain

Pitch: 520

Length: 112

Please note that the chain shown in this listing is for size reference only. For the correct chain type and grade, please refer to the vehicle's manufacturer manual.

Gear Ratio Chart

TeethFront Sprocket
13
Rear Sprocket382.92
-20.8%
463.54
-4.2%
473.62
-2.1%
483.69
standard
493.77
+2.1%
503.85
+4.2%

Lower gear ratios allow for higher top speeds.

Higher gear ratios increase torque for better acceleration.

Full Gear Ratio Chart (pdf)