Bicycle Part Shifter - Gear Shifter | Type of Shifter and Fuction

​There are few types of gear shifter in the market namely, THUMB shifter, GRIP shifter,  TRIGGER shifter, Flight Deck shifter (road bike). You must know the function of gear shifter and how to use the gear shifters in order to shift the chain to different gears.

Bicycle Part - Gear Shifter

A bicycle shifter or gear control or gear levers is a component used to control the gearing mechanisms and select the desired gear ratio. Typically, they operate either a derailleur mechanism or an internal hub gear mechanism. In either case, the control is operated by moving a cable that connects the shifter to the gear mechanism.

Traditionally shifters were mounted on the down tube of the frame or stem. For ergonomic reasons, they tend to be located somewhere on the handlebars on modern bicycles.

There are various types of shifter:

1. Grip shifter - a wheel with click stops surrounding the handlebar is turned until the desired gear is reached, though typically one gear at a time
   
2. Trigger shifter - a lever is pulled or pushed to change gears one at a time
   
3. Thumb shifter
   
4. Road bike shifter - integrated with brake levers, sometimes known as a "brifter"

What is the effect of using HIGH, MEDIUM, LOW gear combinations?
High gear –  Heavy in pedaling (low cadence) but bike move fast (normally flat road).
Medium gear –  Slight lighter than high gear, but bike move slower (normally leisure ride).
Low gear – Light in pedaling (high cadence) but bike move slow (normally slope or uphill).

Reference: wikipedia.org / usjcycles.com