I've only bought 3 CF gear that I can remember. Every one was ounces heavier than the aluminum they were to replace. They've all been much stiffer, so stiff in fact, that I've pulled them from two planes. Sold the other.

I'll take a picture next time I've got one of the CF axled planes down from their racks. I don't fly them much anymore.

The pads really only sandwich the end of the gear leg. They're to add width to support the axle where it goes through the leg. No special shape or anything, they're just the bread in a gear leg sandwich. If just the axle was sticking through that rather thin aluminum gear leg, there wouldn't be enough surface area holding the axle at a right angle to the leg to take the forces transmitted through the wheel up the leg. With the pads, the forces are carried by the ply and the leg, not just the leg.

Try to imagine a thick plywood washer. The axle is a tight fit through that washer. The axle sticks through the leg with a washer one each side of the leg. All that is epoxied solid. The epoxy bonds the washers and axle to the leg and basically turns all that into one solid composite.

BTW, the wheel is held on the axle with a small washer that's epoxied on. Another simple and lightweight detail. It's also more streamlined. The washer is against the wheel of course with about 1/32" of the axel sticking out. The epoxy is a fillet around the washer. I figure the streamlining alone gives the airplane maybe 15-20mph greater top speed.............. on each side...........