2015 - 2021
BETA RR 390
Rear steel sprocket - 52 teeth
| JT Sprockets
Fits to:
BETA RR 390 ENDURO 4T EFI Racing [2017 - 2020]
BETA RS 390 [2015 - 2016
BETA RR-S 390 ENDURO 4T [2017 - 2019]
BETA RR 390 EFI Racing [2017 - 2021]
BETA RR 390 ENDURO 4T EFI [2016 - 2019]
BETA RR 390 ENDURO 4T [2015 - 2021]
2020 - 2021 BETA RR 390
Transmision ratio:
| 11 | 12 | 13 | 14 | 15 | 16 | ||
| 38 | 3.45 -8.3% | 3.17 -16.0% | 2.92 -22.4% | 2.71 -28.0% | 2.53 -32.8% | 2.38 -37.0% | |
| 39 | 3.55 -5.9% | 3.25 -13.8% | 3.00 -20.4% | 2.79 -26.1% | 2.60 -31.0% | 2.44 -35.3% | |
| 40 | 3.64 -3.5% | 3.33 -11.6% | 3.08 -18.4% | 2.86 -24.2% | 2.67 -29.3% | 2.50 -33.7% | |
| 42 | 3.82 +1.3% | 3.50 -7.1% | 3.23 -14.3% | 3.00 -20.4% | 2.80 -25.7% | 2.62 -30.4% | |
| 43 | 3.91 +3.7% | 3.58 -4.9% | 3.31 -12.2% | 3.07 -18.5% | 2.87 -23.9% | 2.69 -28.7% | |
| 44 | 4.00 +6.1% | 3.67 -2.7% | 3.38 -10.2% | 3.14 -16.6% | 2.93 -22.2% | 2.75 -27.0% | |
| 45 | 4.09 +8.5% | 3.75 -0.5% | 3.46 -8.2% | 3.21 -14.7% | 3.00 -20.4% | 2.81 -25.4% | |
| 46 | 4.18 +10.9% | 3.83 +1.7% | 3.54 -6.1% | 3.29 -12.8% | 3.07 -18.6% | 2.88 -23.7% | |
| 47 | 4.27 +13.4% | 3.92 +3.9% | 3.62 -4.1% | 3.36 -10.9% | 3.13 -16.9% | 2.94 -22.1% | |
| 48 | 4.36 +15.8% | 4.00 +6.1% | 3.69 -2.0% | 3.43 -9.0% | 3.20 -15.1% | 3.00 -20.4% | |
| 49 | 4.45 +18.2% | 4.08 +8.3% | 3.77 standard | 3.50 -7.1% | 3.27 -13.3% | 3.06 -18.8% | |
| 50 | 4.55 +20.6% | 4.17 +10.5% | 3.85 +2.0% | 3.57 -5.2% | 3.33 -11.6% | 3.12 -17.1% | |
| 51 | 4.64 +23.0% | 4.25 +12.8% | 3.92 +4.1% | 3.64 -3.4% | 3.40 -9.8% | 3.19 -15.4% | |
| 52 | 4.73 +25.4% | 4.33 +15.0% | 4.00 +6.1% | 3.71 -1.5% | 3.47 -8.0% | 3.25 -13.8% | |
| 53 | 4.82 +27.8% | 4.42 +17.2% | 4.08 +8.2% | 3.79 +0.4% | 3.53 -6.3% | 3.31 -12.1% | |
| 54 | 4.91 +30.2% | 4.50 +19.4% | 4.15 +10.2% | 3.86 +2.3% | 3.60 -4.5% | 3.38 -10.5% | |
| 55 | 5.00 +32.7% | 4.58 +21.6% | 4.23 +12.2% | 3.93 +4.2% | 3.67 -2.7% | 3.44 -8.8% | |
Specifications
| Manufacturer | JT Sprockets |
|---|---|
| Color | Black| Red |
| Chain pitch | 520 |
| Position | Rear |
| Number of teeth | 52 |
| Style | Twinstar |
| Units | Each |
| Material | 7075-T6 Aluminum| Carbon Steel |
| Type | Drive |
Product description
Steel outer ring Heat-induction hardened high-carbon steel JT advanced tempering process achieves hardness that could last six times longer than a 7075-T6 aluminum sprocket, enhancing power transfer performance Alu core Lightweight aviation-grade ergal 7075-T6 aluminum Precision made using state of the art laser cutting and CNC equipment, resulting in an ultra lightweight race power design