size wheels questions

[freddyfingaz]

I want to buy 24"X2.125" rear tire, my question is What's min width of rim that will work with 2.125 width of tire?

What's thinnest 20" width tire and wheel I can get? My guess is 1 1/8.

 

[freddyfingaz]

I learn that outer diameter is not only thing I have to look for but I also have to look for bead size. For example, jerald 24x2.125 slick tire has 507mm bead. To find rims that has 507mm bead and thinnest 24" has 507mm would be 1.75.

My 20" 28 spokes is coming. Now it's time for looking for thinnest tire for it.