If the shifter knob of a motorcycle is broken off completely, it can be challenging to shift gears in the conventional manner. However, it is still possible to ride a motorcycle without shifting gears if the bike has an automatic transmission or a semi-automatic clutch system.
Automatic Transmission: Some motorcycles come equipped with automatic transmissions, similar to those found in cars. These motorcycles do not require manual shifting, as the transmission automatically adjusts gears based on the engine's RPM and load. In this case, you can ride the motorcycle without needing to shift gears manually.
Semi-Automatic Clutch System: Certain motorcycles feature a semi-automatic clutch system, also known as a "clutchless" or "auto-clutch" system. With this type of system, you don't need to use the clutch lever to shift gears manually. Instead, you can shift gears by simply using the gear shifter without needing to engage the clutch manually. The system automatically disengages and engages the clutch for you, allowing for gear changes without using the clutch lever.
The shifter knob provides the necessary leverage and grip to engage the transmission properly. Without it, you may struggle to find the correct gear position, and attempting to shift without the knob could cause damage to the transmission.
In such a situation, it is advisable to have the shifter knob repaired or replaced by a professional before riding the motorcycle again. Attempting to ride without the ability to shift gears properly can be unsafe and may lead to accidents or damage to the bike.