SSR SR125TR 420 15T Front Sprocket – 20mm Upgrade
Brand-new unbranded 420 pitch, 15-tooth front sprocket for SSR SR125TR applications using the larger 20 mm countershaft pattern.
Product Details
- Position: Front / countershaft sprocket
- Chain pitch: 420
- Tooth count: 15T
- Countershaft family: Large 20 mm type
- Spline count: 6
- Condition: Brand new
- Type: Unbranded aftermarket replacement
- Quantity: 1 sprocket
Verified Fitment Family
| Make / Engine | Application | Notes |
|---|---|---|
| SSR | SR125TR / SR125TR-BW large-countershaft engine family | TBolt identifies SSR 125TR with the larger 20 mm shaft; SSR parts data confirms 420 final drive |
Important Fitment Information
The SR125TR engine parts schematic lists a 14T countershaft sprocket as standard on documented models. This 15T sprocket should therefore be treated as a gearing change, not an OE-equivalent tooth count.
Moving from 14T to 15T generally raises the overall final-drive ratio: slightly less acceleration and lower engine rpm at a given road speed, subject to the rest of the gearing.
Do not order by engine capacity alone. Chinese horizontal engines use more than one countershaft spline size. Many YX/Piranha engines and several SSR/Pitster Pro models use the smaller 17 mm pattern, which is not the same as this 20 mm sprocket.
What's Included
One 420 pitch, 15-tooth front sprocket. Retainer plate, bolts and other fitting hardware are not stated as included.
Installation
Confirm chain pitch, shaft spline size, chain alignment and sprocket-retainer arrangement before fitting. Inspect the drive chain and rear sprocket for wear and replace worn drivetrain components as required.