Online Catalogue
KTM 250 SX-F Racing
2015 to 2020
Front Sprocket
Lightweight Self-Cleaning Front Sprocket
Rear Sprocket
Lightweight Self-Cleaning Rear Sprocket
Steel Rear Sprocket
Part Number: JTR897
Teeth: 51 Check Availability
Available Sizes: 38, 40, 41, 42, 43, 44, 45, 46, 47, 49, 50, 52, 53
Racelite Aluminium Rear Race Sprocket
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
| Teeth | Front Sprocket | |||||
| 11 | 12 | 13 | 14 | 15 | ||
| Rear Sprocket | 38 | 3.45 -5.2% | 3.17 -13.1% | 2.92 -19.8% | 2.71 -25.5% | 2.53 -30.5% |
| 40 | 3.64 -0.2% | 3.33 -8.5% | 3.08 -15.5% | 2.86 -21.6% | 2.67 -26.8% | |
| 41 | 3.73 +2.3% | 3.42 -6.2% | 3.15 -13.4% | 2.93 -19.6% | 2.73 -25.0% | |
| 42 | 3.82 +4.8% | 3.50 -3.9% | 3.23 -11.3% | 3.00 -17.6% | 2.80 -23.1% | |
| 43 | 3.91 +7.3% | 3.58 -1.6% | 3.31 -9.2% | 3.07 -15.7% | 2.87 -21.3% | |
| 44 | 4.00 +9.8% | 3.67 +0.7% | 3.38 -7.1% | 3.14 -13.7% | 2.93 -19.5% | |
| 45 | 4.09 +12.3% | 3.75 +2.9% | 3.46 -5.0% | 3.21 -11.8% | 3.00 -17.6% | |
| 46 | 4.18 +14.8% | 3.83 +5.2% | 3.54 -2.9% | 3.29 -9.8% | 3.07 -15.8% | |
| 47 | 4.27 +17.3% | 3.92 +7.5% | 3.62 -0.8% | 3.36 -7.8% | 3.13 -14.0% | |
| 49 | 4.45 +22.3% | 4.08 +12.1% | 3.77 +3.5% | 3.50 -3.9% | 3.27 -10.3% | |
| 50 | 4.55 +24.8% | 4.17 +14.4% | 3.85 +5.6% | 3.57 -2.0% | 3.33 -8.5% | |
| 51 | 4.64 +27.3% | 4.25 +16.7% | 3.92 +7.7% | 3.64 standard | 3.40 -6.7% | |
| 52 | 4.73 +29.8% | 4.33 +19.0% | 4.00 +9.8% | 3.71 +2.0% | 3.47 -4.8% | |
| 53 | 4.82 +32.3% | 4.42 +21.2% | 4.08 +11.9% | 3.79 +3.9% | 3.53 -3.0% | |
Lower gear ratios allow for higher top speeds.
Higher gear ratios increase torque for better acceleration.
JTF1901SC is a Lightweight Self-Cleaning sprocket