We buy the light duty cart from a cart vendor, not our design. (As a side note, we will be changing to a much better [standard] cart in the near furtue...not sure exactly when.) These wheels are basically golf bag/cart type. Side loading or heavier loads seems to compress the thread and then force it to peal off the rim. If you have gear in the boat or travel distances, have rough grounds, uneven grounds...it is a problem. The cart has a load limit that is basically the weight of the boat alone. I think you could use sikaflex or 3M 5200 to bond the rubber on better.
We suggest the heavy duty upgrade wheels as one solution. We also have a great new all around cart... the HOBIE Trax.
HobieTrax Cart. #80044001
This is a heavy duty cart with pneumatic tires. The best all around cart for heavier loads and soft sand.