It is generally not recommended to stop at a red light or a stop sign while still in second or third gear on a motorcycle, including a Harley Sportster. Downshifting and coming to a stop in the appropriate gear is the recommended practice for several reasons:
Control and safety: Downshifting to first gear before stopping allows you to have better control of the motorcycle when you need to start moving again. Being in first gear ensures that you have immediate power available to respond to any sudden changes in traffic conditions or emergencies.
Engine and transmission wear: Stopping in a higher gear and then downshifting can cause increased wear and tear on the engine and transmission components. When you downshift while the motorcycle is still moving, the engine speed (RPM) needs to match the lower gear's speed. This can result in abrupt clutch engagement and additional stress on the drivetrain.
Smoothness and comfort: Downshifting to first gear while coming to a stop allows for a smoother transition and avoids any jerky movements. It also reduces the risk of stalling the engine, which can be inconvenient and potentially unsafe in certain situations.
It's always best to follow the manufacturer's recommendations outlined in your motorcycle's owner's manual. Most manuals provide guidance on downshifting procedures for various riding conditions. By downshifting to first gear while approaching a stop, you'll ensure better control, reduce wear on your bike's components, and have a smoother overall riding experience.