What type of shock absorber is this, and what are my options for upgrading without replacing the whole bike?

coil spring.


ask at a bike shop in person.

What bike is it on?
It's a coil shock.
Shocks are usually primarily described according to length between eyelets and stroke.
Can only see one eyelet on yours, which makes it tricky.

Coil spring. For the most part, upgrade options are very limited, since they are typically only found on low-end bikes (or dedicated down-hill bikes).

What's wrong with it? Sometimes you can get replacement springs if you want it softer or stiffer.