I don't know what you call them, but I have seen wheels you can put under cars or motorcycles to roll them around a garage for easy storage or movement.
Anybody ever see one to fit the spyder?
Harbor Freight has a set for a car,you could use 3 and have a spare. They would handle the weight.
............... But they also sell a much less expensive option .... the small wood w/ caster wheels furniture dollies .... 12" X 16" around $15 ea. you can buy Three .... I have them and they are great for the Spyder ....... I got mine at Home Depot for $ 8.00 each ...... 5 yrs ago ...... inflation ............. Mike
I love the harbor freight furniture dollies. The wheels kept breaking on the stool that I use to role around in the garage when working on things at a kneeling level. So I took all the wheels off and mounted the stool to the furniture dolly and haven't had a minutes trouble.
2021 RTL , brake pedal from "Web Boards" chalk white
I think snowmobile dollies will work for you. I used to have a classic Austin mini that I moved around in my garage with them. So I don't see why they would not work for the spyder.