Yes, it is possible to ride a bike without a rear derailleur, although it would affect the bike's functionality and gear-shifting capabilities. The rear derailleur is a crucial component of the drivetrain system that enables the bike to change gears and adjust the chain's position on different cogs or sprockets.
If the rear derailleur is missing or malfunctioning, the bike would typically be stuck in one gear. You would have to rely on the front chainring(s) for gear changes, which would limit your available gear ratios. This can make it more challenging to ride in varying terrains or tackle steep hills.
These bikes have a single gear ratio and lack the complex gear-shifting mechanisms found in multi-speed bicycles. They are popular for their simplicity and low maintenance requirements.
If your bike's rear derailleur is damaged or missing, it's advisable to have it repaired or replaced by a professional bicycle mechanic to restore its proper functionality.