I'm no stranger to changing auto and motorcycle tyres with hand tools in my shed or loungeroom but am having big trubble replacing a 170 / 60 17 ZR M/C (72 W ) Metzeler Roadtec Z6 rear with a 180 / 55 ZR 17 M/C (73 W ) Metzeler Sportec M1
The "new" Sportec was a freebie from a mate who didn't like it on his '96 SuperSport 900.
I mainly do highway miles and got 20,000 km from the old Roadtec with all the wear being in the centre, i.e. awful squared off.
Problem is I can't get either side of the bead to settle properly into the rims. Can get 90% of either side nicely settled, with appropriate lube and smacking with the rubber hammer, but a small inner kink remains on each side. Can move the kink all around the rim but cannot get rid of it, on either side. The inward kink means there is a slit of 10 or so centimetres each side.
Took the wheel down to local servo but the airpump was one of those automatic thingies where you hook up the preset connector to the valve stem, and even though there was a "Flat Tyre " option it couldn't pop the tyre beads into the rims and all the air escaped through the gaps.
Am wondering if I missed sumping in them figures ? To my simple mind a 17 tyre should fit on a rim where another 17 did a coupla hours ago. No ?
In theory it should fit, but if you're having issues it could be from wheel width. Do you know the width of your wheel compared to your friend's SS?
A 170 to a 180 isn't a *huge* jump, though. I would think it would fit without issue.
I haven't changed a tyre myself, but I remember seeing a guy change it, and he used a tie down ratchet strap thingy (that's the technical term) around the circumference of the tyre to seat the bead after the tyre was mounted.
Maybe you should try that.
All sorted, took it to a servo with a normal old air hose, gauge and trigger and both beads snapped into place instantly with the loud pop of poifection.
Those other pumps with the digital press button gadgetery didn't have the necessary ooomph.