A 2.125” tire only went on after an epic battle, and when it came time to remove it, I had to carefully saw it off, steel bead and all! I have changed a lot of bike and uni tires, but never had to resort to this method before, so I thought I should ask before I go and buy a 1.95" Hookworm.
Tire width has nothing to of with how tight a tire fits on a rim. It’s all about bead seat diameter. To some degree it has to do with the ISO tolerances for rim/tire sizes, and the rim design has a lot to do with it. There are some tires that are on the inside of the standard, and they are generally harder to install or remove. If the rim is a hair on the large side, or has a shallow depth that will make it hard as well. The worst case is putting the former tire on the latter rim.
Aside from using motorcycle tire levers I’ve found clamping the beads together on the opposite side of a wheel to be helpful. It makes the beads go into the gutter of the rim so that you can pull the bead off more easily with the extra space created.
You may be able to find out how a 1.95 Hookworm fits (tight/loose) with a google search.
Oh, and to answer your thread title question. General practice is to use a tire that is at least as wide as the rim. So, 47mm, or 1.85".
It sounds like that was the tire’s fault not the rims to me.
I wonder which 2.125 tire it was. My CST Operative didn’t pop on easily, but it wasn’t “hard” to install. Same KH Flatland rim.
It was a 1980s-style Kenda tire, according to this vendor.
Due to the unusually snowy weather, I do a lot of indoor idling these days. I found that tire on the street and thought it would be smoother on linoleum than the knobby 2.4 that our unis came with. After doing the Google searches you recommended, though, I think that scavenged tire had a bit of dry rot, so it’s just as well that it’s out of circulation.
The CST Operative looks good, but I like the fact that the Hookworm can be pumped up to 110psi.
The hookworm, at least in 26 inch is a great tire, albeit a bit heavy. You won’t be disappointed.
I’ve never had to use spoons to remove the 2.5" 26er version on a dominator2 rim, but that isn’t exactly similar to your situation.