RD400 Tires Wont Seat On Beads Correctly

[Aaron Russell]

Hello everyone,
I got a pair of Avon AM26s (110/90-18 90/90-18) for my RD and when i went to put them on my balancer I noticed that it wasn't spinning straight and the bead was not seated correctly, ive had 90 pounds of air in them, tried everything I knew but couldn't get it to seat (both tires).
Ended up taking them to cycle gear to see if they can do it, 45 hours later, found out they could not.
Anyone have this problem, and any suggestions?
Thanks

[DesmoDrew]

   Make sure the inside of the rim is clean and smooth, especially where the tire has to slip up onto the bead area of the rim.  I have a wire brush wheel in an old drill that I clean and polish tube type rims with.  Tubeless rims are usually no issue, but tube type seem to grow a layer of oxidation and old rubber bits.  If it is sunny and warm, leave the tire(s) in the sun for 30min or so to soften up.  And use a good tire mounting lubricant, not dish soap.  I use 'Murphys tire and tube mounting compound'.  12-15psi is all it ever takes.

[m in sc]

ive had good luck using of all things, windex, on the sidewall to get it to seat it can be frustrating.

[Hawaii-Mike]

The owner of a local cycle shop gave me a great tip.  Put automotive grease around the lip of the tire.  That helps a lot - more than soapy water, armor all etc.

If needed, I will inflate the tire up to 100 psi, carefully to pop the bead out.  I might inflate and deflate it 5 times. If the tire is not defective it's possible to get the bead seated properly.

[pdxjim]

Drew has the right info.

[DesmoDrew]

I forgot to mention to remove the valve core so the air pressure can build faster, giving that extra push.

[1976RD400C]

I have deflated it and push and hold the bead down and in across from where the bead wasn't seating up as you reinflate.

[Aaron Russell]

Make sure the inside of the rim is clean and smooth, especially where the tire has to slip up onto the bead area of the rim.  I have a wire brush wheel in an old drill that I clean and polish tube type rims with.  Tubeless rims are usually no issue, but tube type seem to grow a layer of oxidation and old rubber bits.  If it is sunny and warm, leave the tire(s) in the sun for 30min or so to soften up.  And use a good tire mounting lubricant, not dish soap.  I use 'Murphys tire and tube mounting compound'.  12-15psi is all it ever takes.

There was some oxidation, didnt think it was bad, ill take them back apart and polish them up, see if it helps.

[RDnuTZ]

Make sure the inside of the rim is clean and smooth, especially where the tire has to slip up onto the bead area of the rim.  I have a wire brush wheel in an old drill that I clean and polish tube type rims with.  Tubeless rims are usually no issue, but tube type seem to grow a layer of oxidation and old rubber bits.  If it is sunny and warm, leave the tire(s) in the sun for 30min or so to soften up.  And use a good tire mounting lubricant, not dish soap.  I use 'Murphys tire and tube mounting compound'.  12-15psi is all it ever takes.

I also use the wire brush in drill method. Been working on multiple DID & Takasago Aluminum dirt bike wheels from the 1970's and most rims have heavy corrosion and oxidation. If the wire wheel can't get all of it, I'll resort to a rasp or rat tail file to shave down the worst of it. I also stand on the tire at the trouble spots while inflating if needed to help them pop up. Also sometimes a ratcheting tie down around outer circumference of the tire can work too for popping a bead on.