Thumb: Shifters that are mounted on the handlebar and gear changes are made exclusively by pushing or pulling the lever with the thumb (commonly found on older or simpler bicycles).
Brake levers: Integrated system that combines the gear shifter and brake lever into a single mechanism (common on road/racing bikes and entry-level mountain bikes).
Rotary: Shifters that are an extension of the handlebar grip and allow gear changes by rotating them forward or backward (ideal for city and children's bikes).
Trigger: Shifters that are mounted under the handlebar (mainly on MTB and Trekking bikes) and usually use two separate levers for shifting gears with the thumb and index finger.
