Been meaning to join this forum for a while, to learn how to better care for our old pool which we flipped to salt water when we bought this house a couple of years ago.
Anyways...doing a Google search for Polaris vacuums and broken wheels..this thread showed up.
We're on our second year with the Polaris 9300 sport. Bought it end of June last year...ran great all year.
This spring, about 4 weeks ago..took it out for our first spring cleaning...let it loose in the pool..checked on it about a hour later, saw the broken wheel in the pool. Noticed it sheared off right at the hub. Having a mechanical engineering background and lots of plastic modeling experience...thought to mysef "Jeeze..that plastic is mighty thin there around that hub...VERY WEAK...no wonder it snapped off!" And since it's the rear wheels...the lateral stress they receive (as another engineer noted in a prior post) when it bounces down on the bottom of the pool after climbing the walls...and slowly slips down, is enough to weaken them over time. Those rear wheels should have much thicker plastic, as well as ribbed reinforcements (like spokes)...beefing up the hub area. Probably softer tires too to absorb some of that shock upon impact.
Submitted a request at their website for a replacement wheel...about 2 weeks later one arrived, put in on the vacuum....got to use it a few more times and then this past weekend I let her loose in the pool...checked on it about an hour later...and what do you know, the left rear wheel broke off. Same thing...right around the hub.
Warranty expires in 2 weeks...none the less, I went to their website yesterday to submit another claim/request for another wheel.
Our pool is in ground, and in the deep end, steep nearly vertical walls with a kiddie walk around the deep end. Unusual pool..hand shaped concrete, built in '74 I think. 2 years ago we put a custom pool liner in it.
Someone in this thread mentioned beefing up the wheels with marine epoxy...I plan on doing that...scuff up the plastic with some sandpaper (so it will adhere well) and lay on a good thickness of epoxy.
Only other complaint about these Polaris cleaners is they seem to be programmed to spend too much time on the vertical walls of the pool. Seems like they spend 75% of their time climbing them. My debris/leaves/worms are on the bottom of the pool vacuum..spend your time on the bottom!