Thanks for the tip, HR. I use 4" DuBro inflatable Big Wheels, and until last weekend, ran the collars inside with never a loss. Transporting the plane intact in the back of my truck, I had a problem with the bed lid pressing down on the top wing and compressing it about an inch, so I decided quick removal of the wheels was in order to cure that problem. On the gear I made, I left enough axle to mount a collar externally if need be, so fuel hose is out of the question, as is CA.

I'd like to just put a real cap screw in the collar, but I don't know what thread size is in the 3/16" collars. Any clue?

Thanks,

Dave