in: XC Riding
This is a handmade "Tire Changing Platform" (box) made out of plywood.
I designed it large enough to hold a 26", 27.5" or even a 29" rim. However, when I built it, I did not make the inside "hole" to fit a cog larger then 38 tooth. I now have a bike with a 48" tooth sprocket. It still works, as long as the cassette is "UP" and not facing the hole.