Why are the wheels on my pool vacuum gummy?

The wheels on your pool vacuum may be gummy due to a buildup of debris, algae, or chemicals in the pool water, which can lead to degradation of the rubber or plastic materials. Exposure to pool chemicals, such as chlorine, can also cause the wheels to break down over time. Regular cleaning and maintenance can help prevent this issue, as well as storing the vacuum properly when not in use. Replacing the wheels may be necessary if they are too damaged.