Hello all,

I am in the process of building a new road bike, and have run into what I hope is a fairly simple problem. There seems to be a bulge on the top side in my tires, both front and back. The rims are new vuelta aeromax, the tires are new Heng Shin, the inner tube is bontrager 700x18-23. It almost seems like the inner tube or tire doesn't fit properly. i have not even ridden the bike yet - still building it. Any help would be much appreciated.

Mike

Let the air out of them, and push the valve up into the tire. Sounds like you have some tube caught under the bead.

+1
Does the "bulge" just happen to coincide with the valve stem?

Yes, On the rear tire, the "bulge" is at the valve stem. I tried pushing it up into the tire as mentioned by Wanderer above, but that did not work for the rear tire. It did help the front tire though... Any other ideas?

If you let the air out of the tube and then pry back the tire's side/bead to view inside the rim along the bead seat you might see a bit of the tube poking between the tire and the rim, where the tire bulges. Often at the valve because of the valve's base being a thicker wall thickness then the rest of the tube. The fix would be wiggling/prying the tire back and forth until the tube fits within the tire completely. Andy.

Practice.

Is the tire bead seating OK?

How do I check if the tire bead seating is OK? I know these seem like some very basic stuff, but I have never had any problems like this with my tires...
Thanks.

Well the obvious answer is to see if there's a hump in the tire... Most tires have a thin molded rib/line just above the bead. When mounted on a rim this line should sit about 1-3mm's above the rim, BUT more important then the 1-3mm's is that this line should sit the same amount above the rim all the way around the wheel and on both sides. A close look at while slowly spinning the wheel is usually enough to follow this line and it's proximity to the rim. Andy.

Thanks for your help - it seems there is lump in the tire itself...

Don't you just hate it when that happens?

Let the air out of the tube, then take one side of the tire off of the rim and make sure the tube isn't caught anywhere or wrinkled up on itself. Then put the tire back on the rim, allign the valve in the rim hole and put a small ampunt of air in the tube to keep it from getting caught between the tire and rim. You should be able to see the rim tape on either side of the tire. This is an indicator the tube is properly located inside the tire. Then make sure you squeeze the beaded area of the tire together and push it downward into the "well" ( center ) of the rim. This centers the tire/tube on the rim so it seats correctly. Then add about 50% of the required ampunt of air, watching to make sure the tube doesn't escape the tire carcass. Check all around the rim for consistancy of fit. Then continue to inflate the tire pressure to the required amount. You can move the tube inside the tire during the initial mounting process more easily by using talcom powder on the tube before inserting it in the tire.

a pic might help.