This looks like they could be good replacement parts for the hawk sticks. I haven't used them myself and there might be a better alternative out there but I think urethane is a durable product.
Hawk Helium Climbing Stick - Suction Cup - Repair / Replacement Kit - Button | eBay
We started out 3d printing these, but they've been so popular we moved to injection molding! The new design is sleeker, and compatible with hawk helium hardware, as well as our past 3d printed versions.
www.ebay.com