JT Sprockets

Online Catalogue

KTM 250 SX-F Racing

2015 to 2020

Front Sprocket

Lightweight Self-Cleaning Front Sprocket

Part Number: JTF1901SC

Teeth: 14

Available Sizes: 13, 14, 15, 16

Steel Front Sprocket

Part Number: JTF1901

Teeth: 14

Available Sizes: 11, 12, 13, 14, 15

Rear Sprocket

Steel Rear Sprocket

Part Number: JTR897

Teeth: 51

Available Sizes: 38, 40, 41, 42, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53

Aluminium Rear Race Sprocket

Part Number: JTA897

Teeth: 51

Available Sizes: 38, 40, 42, 45, 47, 48, 49, 50, 51, 52

Drive Chain

Pitch: 520

Length: 118

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
111213141516
Rear Sprocket383.45
-5.2%
3.17
-13.1%
2.92
-19.8%
2.71
-25.5%
2.53
-30.5%
2.38
-34.8%
403.64
-0.2%
3.33
-8.5%
3.08
-15.5%
2.86
-21.6%
2.67
-26.8%
2.50
-31.4%
413.73
+2.3%
3.42
-6.2%
3.15
-13.4%
2.93
-19.6%
2.73
-25.0%
2.56
-29.7%
423.82
+4.8%
3.50
-3.9%
3.23
-11.3%
3.00
-17.6%
2.80
-23.1%
2.62
-27.9%
444.00
+9.8%
3.67
+0.7%
3.38
-7.1%
3.14
-13.7%
2.93
-19.5%
2.75
-24.5%
454.09
+12.3%
3.75
+2.9%
3.46
-5.0%
3.21
-11.8%
3.00
-17.6%
2.81
-22.8%
464.18
+14.8%
3.83
+5.2%
3.54
-2.9%
3.29
-9.8%
3.07
-15.8%
2.88
-21.1%
474.27
+17.3%
3.92
+7.5%
3.62
-0.8%
3.36
-7.8%
3.13
-14.0%
2.94
-19.4%
484.36
+19.8%
4.00
+9.8%
3.69
+1.4%
3.43
-5.9%
3.20
-12.2%
3.00
-17.6%
494.45
+22.3%
4.08
+12.1%
3.77
+3.5%
3.50
-3.9%
3.27
-10.3%
3.06
-15.9%
504.55
+24.8%
4.17
+14.4%
3.85
+5.6%
3.57
-2.0%
3.33
-8.5%
3.12
-14.2%
514.64
+27.3%
4.25
+16.7%
3.92
+7.7%
3.64
standard
3.40
-6.7%
3.19
-12.5%
524.73
+29.8%
4.33
+19.0%
4.00
+9.8%
3.71
+2.0%
3.47
-4.8%
3.25
-10.8%
534.82
+32.3%
4.42
+21.2%
4.08
+11.9%
3.79
+3.9%
3.53
-3.0%
3.31
-9.1%

Lower gear ratios allow for higher top speeds.

Higher gear ratios increase torque for better acceleration.

Full Gear Ratio Chart (pdf)