I am trying to fit a new Pirelli MT21 90/90/21 to my XT660Z's factory front wheel. The old Tourance came off reasonably easily. The replacement MT21 went on fairly easily too, that's when the fun started.

With the valve core removed, I lubed the rim/bead with a soapy solution and proceeded to inflate the tyre, with a 7.5hp 275L compressor, to 50, then 60 then 70 psi, no pop of the bead seating. The tyre appears to be evenly "seated" on the rim, but when I deflated the tyre the bead was still loose, I was able to push it away from the rim with just my thumbs.

I have repeated the procedure several times, using glass cleaner as a lube, with the same result. I put the wheel and tyre in a warm (23*C) room last night, same result this morning. I have tried the ratchet strap method, I have tried bouncing the inflated wheel, and hitting the inflated tyre with a rubber mallet, but it is still not seating.

I am at the end of my tyre fitting skill set, can anyone suggest what might be wrong and how to fix it? I am wary of going past 70psi.

Thanks, RS.

Have you thought of using tyre soap?..ie what the shops use..

Spend the money and go get it fitted...�10 and no stress..

Unfortunately the only tyre shops anywhere near me won't fit bike tyres, although one took a look at how the tyre was seated on the rim and pronounced it "grand". The nearest bike shop to me is nearly 100KMs away.
Guess I'll take it for a short, gentle spin and see what happens.

Sorry fella I got no idea where you are...daft idea maybe... put the old tyre back on a carry the new one over your shoulder on your bike as you go to the bike tyre shop..

I wouldnt personally ride with a suspect tyre no matter what. Your safety,and that of other road users is worth a damn site more than the travel costs...

The front rim does not have the extra inner wall as the rear tire does.

If it is evenly seated and rides without "bumping" just be happy and ride the damn thing ;-)

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2011 Yamaha XT660Z ABS T�n�r�.

• Puig +8cm dark screen, Garmin Zumo 220, Scottoiler eSystem v2
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Can I suggest that you deflate the tyre, push the bead in on both sides, then add air until the tube has barely taken its proper shape. This way it won't jam between the tyre bead and the rim. Make sure the tube isn't pinched anywhere, and push the valve stem in most of its length (with the nut on, of course), lube the bead both sides (soapy water will do), and pump the thing up.

It should be ok. I have used MT21s before and don't remember them being troublesome, but things change...

As has been previously mentioned - the front is not a safety rim. Only the rear has a safety rim, with a lip to prevent the tyre bead slipping inwards when low on pressure or deflated. Up front there is nothing for the bead to pop into, so you will be able to push it inwards when there's no air in the tyre.

I think you are possibly fighting a problem that doesn't actually exist!

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