Tyre won't seat nicely - bead too short?

by cat1commuter   January 21, 2014  

The pair of Schwalbe Marathon XR 26x1.6" tyres which I have on my winter commuting bike won't seat properly. The previous pair of the same model were fine. In fact I liked them so much that I bought this extra pair some time ago when I discovered that Schwalbe had discontinued this model. They're folding tyres, with a kevlar bead, and it seems that the bead is a little too short, which produces one or two low spots on the tyre, so I'm not rolling on round wheels and the ride is a bit lumpy. I hoped they'd settle in, but I've done a few hundred miles and they haven't stretched. I've also tried taking them off and trying to stretch the bead, and have blown them up hard to greater than running pressure. I'm about to give up on them and buy some different tyres, but can anyone suggest something I haven't yet tried?

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An old friend suggested fairy liquid rubbed along the side and then over inflating to smooth off.

posted by NIrish [23 posts]
21st January 2014 - 17:06

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Thanks, I'll give that a try. (Though in my case it will have to be Ecover!)

two wheels good; four wheels bad

posted by cat1commuter [1301 posts]
21st January 2014 - 18:40

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Success! Just tried this. Diluted a little washing up liquid with a little water. Wearing a nitrile glove, and with wheel flat on floor, tyre fitted but with inner tube deflated, it was easy to smear liquid along the bead with a finger, then flip the wheel over to do the other side. The tyres have a max. inflation pressure of 85 psi, and I went up to 100. Rear tyre went "pop", and bead was seated nicely. Front tyre had a spot where the bead refused to pop out. I deflated it again, put more liquid over the spot which refused to emerge, and re-inflated to 100 psi. Bead still didn't pop out. In desperation I pressed on it with the rounded, blunt end of a plastic tyre lever, and it eased out into place. Let tyres down to working pressure of 55 psi front / 60 rear, and the beads stayed in place. There's a tiny ridge on the tyre at the edge of the area which is designed to contact the rim, and I think this might have been catching on the edge of the rim, preventing it from seating properly.

two wheels good; four wheels bad

posted by cat1commuter [1301 posts]
2nd February 2014 - 17:44

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