Need help with tire fitment problems

[limeex2]

I Have larger spoked rims with hd spokes laced up to GS hubs. Running them on a GS1100e. The problem is with the rear. Bought a new pair of Pirelli Sport Demons. Front rim size is 18"x2.75" A 110/80 x 18 fits fine and properly. Rear rim size is 18"x3.0" I have a 140/70 x 18 tire that will not bead up properly. The very fine line that shows the tire is beaded properly will not pop out enough to show up. Installer says that rim has a 18mm rim lip and tire bead line is 15mm. Standard stock rim has a 15mm lip. I ran standard tires, race tires, even slicks, with no issues back in the day, but that was 25 years ago. Avon fitment chart says to run a 140mm tire. Dunlop says to run a 130 tire. I could not find a Pirelli fitment chart. Would going to a smaller tire get the bead size I need? Manufactures are not giving me much help. I need help, this is one of the last hurdles before I can get my build on the road.

[Steve]

That line is there as a convenience, not a mandate. It will allow you to easily see if the bead is not set properly, but if it's below the edge of the bead, you will never see it. The only thing that I would suggest is to rotate the tire and watch the edges to make sure everything looks good. If the tire is not seating properly, you will see the sidewall dip down a bit where it is not seating properly. Of course, that will drag the edge of the tread, too, and will cause some strange things to happen as the tire meets the road. If everything looks smooth and wrinkle-free, I would say 'run it'. If it's not quite right, break the bead, apply a bit of tire lube, try again.

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