Most of the accessories and parts associated with motorcycles are used to facilitate the better and smooth running of the vehicle or to protect the bike and its essential parts in case of an accident, a similar task is performed by a spool in a bike.
Spools are attached to the swing arm in a bike and perform very similarly to a frame slider, and it also helps us in raising the rear end of a motorcycle in times of need.
Swingarm Spools are designed for protecting your swingarm and axle nut in the event of a crash. They can also be used with a swingarm race stand to lift the rear wheel off of the ground for changing your tire, or oiling your chain.
So, spools are used to live the rear end of a bike which can generally be quite heavy and impossible to mount. These are also made up of strong material to suffice the pressure from the weight of the bike.