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...Matrix put out some rims in the 80's that were genuinely demonic. There was no space at all on the interior to drop the bead into, and they were pretty narrow, IIRC. I still have some on a bike. When the tyre goes flat, I'll probably just give it away.

I was mounting a Schwalbe Marathon onto a Matrix rim when I first researched and discovered the bead jack. I've never looked back.