Tyre bead problem

Yamaha TT600R winter overhaul.

OK, so I got the rear wheel sorted and the tyres off both
wheels. Mounting the rear tyre (that was a bitch to get of)
was easy. The front tyre (that more or less jumped off
the rim voluntarily) will not seat properly.
This is a 90/90-21" tyre with a tube on a takasago spoke
rim. I get it on the rim and one side plus 3/4 of the other
seats perfectly. I have emptied and filled the tube a
number of times, I have used a lot of tyre mounting "soap",
I have tried with the tyre rotated to different positions
on the rim. I tried bouncing the wheel on the floor and
banging on the tyre with a mallet. It is not always the same
part of the tyre or rim that is involved in the problem.

How much pressure can I use safely, the tyre makers
web site says 45 psig but I've already been at 60?
Can I just go riding and hope some miles on rough
roads will cause the tyre to seat correctly?
What am I missing here?

 

*Don't* try riding with the tyre unseated.

60psi (unloaded) should be safe but normally it's not just a matter of brute
force,
something is stopping the rim getting into position.

The tyre should be marked with a dot to align with the valve housing, for
best balance.

Are the tube and inside of the tyre smooth and well dusted with talc/chalk?

Sometimes it helps to bounce the wheel with only 10-15psi in it to get
things settled.

 

I've been up to 75-80psi on occasions, and it's been OK. I once tried
going higher, and IRC went up to about 90psi and then the pump connector
blew up.

Seriously, I remember reading about a Continental biker tyre destruction
test when they blew the tyres up to something stupid like 150+psi (the
wheels were held underwater to absorb the explosion and debris if they
went bang) and they held.

Use *lots* of tyre soap and take it to 80psi.

It won't. Trust me.

 

OH- pretended :

It depends what you mean by not seating properly...

If you mean the line on the edge of the bead is hidden behind the rim
in one spot, then try more air pressure. I have had this happen. Being
a little timid stopped at 60psi and took it to a tyre fitter. All he
did was take it up to 80psi and it all sorted itself out with a sharp
pop as it dropped into place.

I again struggled with a later tyre, but just did what the tyre fitter
did and took the pressure up some more until it dropped into place.

 

<snip>

Thanks for the advice and encouragement.

Debriefing: I finally won over the tyre by sheer
stubbornness. All that exercise with the hand pump
was probably good for me.
Just to prove that I'm not very good at these
things anymore, I managed to pinch the tube but
that is sorted as well.

 

Heh. Been there, done that.