Originally Posted by
stingray66
MY LBS sells Serfs tubes and keeps giving my 700X28-133 Keeps telling me that 27x1-1/4 are obsolete... ...why are they pushing out the 27 inch size???
New bikes haven't been offered with 27" wheels in roughly 30 years, so they
are obsolete.
You can still find 27" tubes for sale, but my recent experience is that they're typically just repackaged 700c tubes. 700c rims are 8 mm smaller in diameter, but the tubes will easily stretch to fit. You may notice the uninflated tube doesn't want to settle into the tire quite as easily when you're mounting it, but once the tire's mounted, it's business as usual.
Originally Posted by
stingray66
Any way this is the 3rd flat on this bike in a month and its been sitting There is NOTHING in the tire. THE leaks are coming from the tube seams. Tried Kenda 700x28/32c and had the same thing after a few weeks goes flat were the seems are.
I'd be interested to see the punctures. Could be something like a problem with rim tape that leaves an exposed spoke hole or nipple. Could be a bad batch of tubes -- I've seen others mention problems with tube seams, but I've never had an issue myself. If you're having blowouts, could be that your tires (like all recent tires) are meant for hook-bead rims and your older ones have straight walls.
Originally Posted by
stingray66
Also I have FOUR original schwinn tubes form the 70s sitting here and you can see that they are much more thicker AND NOT AS skinny as the 700x28-133.
If you want thick tubes, look for ones that are sold as "thorn resistant". Otherwise, many people prefer thinner tubes for their lighter weight.
As for being "skinny", that's a direct correlation to the tire width the tube is designed for, and how much the designer intends them to stretch. A 28-33 mm tube should be fine for a 1 1/4" tire, but 1 1/4" is roughly 32 mm and at the upper range of that tube's acceptable width. If you want a wider tube, feel free to bump up a size and look for 35 mm tubes. Just be careful when mounting and inflating the tire since there's a bit more rubber you could potentially pinch between the tire and rim at the bead.
Originally Posted by
stingray66
BUT I remember as a kid living in Southern California back in the 60s I had a 10 speed varsity and i rode that thing all over and NEVER had a flat. Today I think the thicker tubes were why.
Almost all of your puncture resistance comes from the tire, not the tube. Once an object penetrates the tire, it'll go through the tube like a hot knife through butter. If it gets through the tire tread and it's longer than your tube and tire are thick, you'll get a flat.
Comparing now to when we were kids, the biggest difference may be rider weight. My preteen kids have never gotten a flat, but I weigh twice what they do and I get flats occasionally. I've got a hunch it's not coincidence. More weight equals more downforce on top of sharp objects you might ride over.