JT Sprockets

Online Catalogue

Yamaha YZ85 P,R,S,T,V,W,X,Y,Z,A,B,D,E,F,G,H,J,K,L Large Wheel

2002 to 2020

Front Sprocket

Steel Front Sprocket

Part Number: JTF558

Teeth: 14

Available Sizes: 13, 14, 15, 16, 17, 18, 20

OE Type Rubber Cushioned Front Sprocket

Part Number: JTF558RB

Teeth: 14 Check Availability

Available Sizes: 16

Rear Sprocket

Steel Rear Sprocket

Part Number: JTR798

Teeth: 52

Available Sizes: 44, 47, 48, 49, 50, 52, 54

Aluminium Rear Race Sprocket

Part Number: JTA798

Teeth: 52

Available Sizes: 47, 48, 49, 50, 51, 52

Drive Chain

Pitch: 428

Length: 124

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
13141516171820
Rear Sprocket443.38
-8.9%
3.14
-15.4%
2.93
-21.0%
2.75
-26.0%
2.59
-30.3%
2.44
-34.2%
2.20
-40.8%
473.62
-2.7%
3.36
-9.6%
3.13
-15.6%
2.94
-20.9%
2.76
-25.6%
2.61
-29.7%
2.35
-36.7%
483.69
-0.6%
3.43
-7.7%
3.20
-13.8%
3.00
-19.2%
2.82
-24.0%
2.67
-28.2%
2.40
-35.4%
493.77
+1.5%
3.50
-5.8%
3.27
-12.1%
3.06
-17.5%
2.88
-22.4%
2.72
-26.7%
2.45
-34.0%
503.85
+3.6%
3.57
-3.8%
3.33
-10.3%
3.12
-15.9%
2.94
-20.8%
2.78
-25.2%
2.50
-32.7%
513.92
+5.6%
3.64
-1.9%
3.40
-8.5%
3.19
-14.2%
3.00
-19.2%
2.83
-23.7%
2.55
-31.3%
524.00
+7.7%
3.71
standard
3.47
-6.7%
3.25
-12.5%
3.06
-17.6%
2.89
-22.2%
2.60
-30.0%
544.15
+11.8%
3.86
+3.8%
3.60
-3.1%
3.38
-9.1%
3.18
-14.5%
3.00
-19.2%
2.70
-27.3%

Lower gear ratios allow for higher top speeds.

Higher gear ratios increase torque for better acceleration.

Full Gear Ratio Chart (pdf)