RE: Ski Flying
As a set for Trikes they are 12 oz. The front is 3.5 oz (2.5"W x 9"L), and the two rears are 4.25 oz (2.5"W x 13"L). They have a center spine and track really well. It was actually very fun just sprinting around on the snow with these things. They ride a bit higher than my 2.75" foam wheels to avoid prop strikes, but are very stable.
I would really recommend them, I think you would have pretty good floatation in just about any snow if you are using a 40 or smaller 60 sized bird. We have had very light, dry "clipper" snow here in the TC and they ride right up on top of it with my NexStar, which is pushing 7 pounds without these things on it.
Curtis