marathon plus tyre untrue

[cwah]

Hello all,

I noticed that every time i install a marathon plus tyre, my wheel becomes untrue. I tried few times to remove the tyre and see if there is a bad tube fitting but I can't really find any.

I tru-ed the rim first to make sure it's not a problem with a bend rim, when I install the tyre afterwards it gives this:
[youtube]C_T5y6U_-Is[/youtube]

You can see a little gap on each wheel revolution near the valve...

Here's the wheel from far:

You can also see the reflective strip slightly lower near the valve...


What is wrong with the wheel? Is it because I installed a 26x2.00 tyre on a narrow rim? I can't fix the problem and I have this issue with all my marathon tyres...

Shall I pop to the bike shop or will they also be useless as usual?

Thank you

 

[2old]

In the video it appears as though the bead hasn't "popped" in one area where the stripe is closer to the rim (or it could be my fading eyesight). You might try putting soap suds on sides of the tire, then inflating to 60 or so psi to see if this resolves the problem.

 

[Chalo]

Yeah, soapy water can work wonders. Often, all you need to do is inflate the tire to beach ball pressure, massage it into an evenly seated shape, then take it up the rest of the way.

Make sure you're not trapping a fold of tube under the tire bead.