When I built the wheel penetration skis for my CH750 I saved the wheel cut outs of aluminum & UHMW plastic. The "Plan B" was to simply deflate the tire and side these inserts in place, holding them installed by re-inflating the tire. There is about a 40% drag / performance for wheel penetration skis vs. straight skis. Snow here is over your knees...approaching waist (CH750 belly skin) deep in many drifts. I deflated the tires and tried to slip the inserts in place..."No Go" the heavy tire simply won't compress enough at -15C temps. Plan C will be removing the weight of the tires completely and bolting the inserts in place to convert to straight skis. I suppose I could just take the UHMW plastic bottom skin off and bolt in a new one without the wheel hole cut out...hmm??? Plan D? The tabs on the inserts were for safety wire if the tire pressure was holding them in place.