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Seating endomorphs

1730 Views 7 Replies 7 Participants Last post by  MauricioB
Why am I having problems? I overinflate them to try to get the bead to pop out, but it is a still a problem. Not something I want to deal with on the trail.

The tire is pretty loose on the rim (Speedway 70's). Is this normal? At low pressures I had problems with the bead slipping off. I was using some narrower tubes. I switched to the Surly's as they just came in and will check it out.
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J-No said:
Why am I having problems? I overinflate them to try to get the bead to pop out, but it is a still a problem. Not something I want to deal with on the trail.

The tire is pretty loose on the rim (Speedway 70's). Is this normal? At low pressures I had problems with the bead slipping off. I was using some narrower tubes. I switched to the Surly's as they just came in and will check it out.
Mine fit pretty loose on speedway 70s but i havent had any issues while riding. I am using surly tubes and i found the best way to mount them is to put enough air in the tube that it helps the tire hold its shape on the rim and then carefully center the bead on the rim on both sides as you start to inflate the tire.At about 20-25 psi the bead seats but it doesnt (pop) on like a smaller tire would.
There are two things going on if the tire is loose on the 70's. Either the bead is stretched (usually from using tire levers) or it is not fully seated. The tires fit tight so they don't spin at low pressures, but at some point using a very small tube and really low pressure, they can drop off the bead seat. When the tire is fully seated, there will be a visible line on the tire evenly spaced all the way around the edge of the rim. If you cannot see this, it is not seated. If it is fully visible all the way around, but deviates further away form the rim in a spot or two, the bead has stretched. I just had to replace a customer's tires who swapped them back and forth between Snow Cats and Large Marges regularly (using tire levers). The tires weren't worn out at all, but had stretched so much they would not stay on any rim.
Try using a lube to seat them properly. The pressure has to be very low for it to come off the bead seat, and at this point the tire is going to wear rapidly. When riding, if you are seeing two creases at 45* angles, the air pressure is too low.
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Thanks. I cannot remember if I used a tire lever to get them on initially (I usually don't with routine changes). I did get a bulge initially and then difficulty getting the bead to seat. My usual tricks did not work. I finally grabbed some windex (it was within arm's reach) and gave it a shot and the bead seated. I think I pushed the envelope on low pressures and the tire stretched. No much I can do at this point but watch it.

Any thoughts on gluing the bead? I've heard of it, but never tried it.
I had a heck of a time seating mine on the fat sheeba rims. I got the tires on the rim by hand but when I inflated them the bead was not even all the way around. I got them to seat by liberally lubing the bead on both sides of the tire and rim with 50/50 dish soap water. Pumped up to 10psi checked bead pumped to 30psi and I was good to go.

Craig
I have endomorphs and 70mm Speedway rims and they do fit loose; I have never used tire levers. I found that if I tried to inflate the tire while upright on the bike there is no way it would seat. If I take the wheel off and place it on it's side, it seats easily. (I imagine I could do this on the bike with the bike on its side.)
I wanted to resurrect this thread, in part because of the good responses, but also because I still have a hell of a time trying to get my endo's fully seated and balanced on my 70mm speedway rims...

To begin with, they are really loose setting up, I definitely have to lay the wheel down on its side to be able to start to inflate, and then need to keep putting the bead back inside the rim where it inevitably falls off as I blow it up.

Then the totally confounding part is that once the tube is inflated enough to keep the bead on the rim, I can pump it up to max pressure and I still can't get the bead evenly seated (so there is always some portion that the little line around the bead is below the rim, rather than visible). I have tried soap and water as lube as well as overinflating, but I still always have what is essentially an uneven or ecentric tire/wheel that you can feel riding on smooth surfaces at any speed.

Further suggestions??? Snow is on its way and I want to be ready...
I've had pretty good luck with all of my Surly tires on the Speedway 70's, but they require that you go to the very end of your patience at times. Here's what I do:

With the wheel off the bike and no tire on the rim, spray the entire outside of the rim with Pledge. Wipe off the inside of the bead ledge.

Put the tire on (without levers...drop the beads into the valley of the rim opposite the diameter of the rim from where you're slipping it on or off) with a partially inflated tube.

Hang the wheel from the clamp handle on workstand or similar (I suppose a tree branch or handlebar would work in the field.) The point here is to avoid making a flat spot.

Inflate to where the bead touches the rim all the way around and then make sure the bead is roughly even, repositioning a little if needed. One of my Larry tires was a problem at this stage because it was a little squished in shipping, so I wrapped a loading strap around the circumference to get the sidewalls to move out a bit (old motorcycle mechanic method.)

Pump to 30 psi or until both beads seat, then deflate to 10 psi. Inspect bead line and re-inflate if necessary.

Granted, a pain in the butt. Low pressure performance has been worth it so far though...
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