On my prior bike (Bianchi Volpe) with 23c and 25c tires at various times, I've never had a problem getting the tube to "fit".
I know they come in various thicknesses and a specific tube will cover a size range, like 21-25 or something, and I know I've used more than one range on a given tire.
But I now have a Felt 35 with Ksyrium Elite wheels and Hutchinson Carbon Comp tires. Today I had to fix a flat and I do what I always do - just remove the old one, replace it and patch it later. Well, when I put the tube in and pumped it up, I saw the tire didn't get seated in the rim where the stem is. I deflated and tried repeatedly to seat it without success with two different tubes. It just didn't seem to have room to get pushed down far enough.
I noticed the tube was thicker than what came with the bike. I do not know what size range they were, but it is possible if they covered the higher end, that would further contribute to the bulk. Putting in a tube that came with the bike that I had patched earlier worked fine.
So, anybody have experience with this? Are these wheels more sensitive to what tubes I can use or is there some trick to this?
Sometimes if, just before you try to seat the section of the tire adjacent to the valve stem, you push the valve stem down into the tire, it allows the tire beads to seat against the rim better.
Thanks, that makes good sense and something I was probably aggravating because when I put the stem in, the first thing I used to do was screw the retaining ring on to hold it in place! I'll try your suggestion next time.