Makes me nervous...
 

I was taking a bicycle maintenance class, and the first thing we did was learn how to swap tubes. I decided to get new tires for my 81 SR at the same time and had the teacher help me pick them. They are wider than my old one. I have the numbers, if it's important.

Anyway, the fit of the new tires was a lot tighter. He helped me get the last hard bit in. I saved the other tire to put on at home, but never got to it. Didn't ride or touch the bike. Next week when I went in, the bead had popped out in one spot.

He was surprised, and said, "that's the one we did together, right?"

So now I'm a little freaked about it. Should I just chalk it up as an anomoly, or is it a sign of something being awry?

Stuff happens. Changing tires is so mundane that sometimes you go through the job on autopilot and miss something obvious. If it worries you have someone check your work.

You went to a class to learn how to replace a bike tube?

No offense, but I think you need to revise your comment. Not that mine are usually any better but i'm feeling nice right now.

I'm sure you are, too.

I didn't think my comment was that nasty. Do you think I should remove it? I have nothing useful to add since I never had a bead pop out on me while the bike was asleep.

A little to much air combined with a non hook bead rim, chrome steel rim, tweeked bead wire, really loose fit, or pinched tube can all cause this. It does not even take max pressure in some cases and sometimes it may take more than a day for the tire to creep off.

I once built a wheel and blew three tubes before I realized I left the rim strip out.

Well, Yeah! That and a bunch of other things. We even mucked with the BB. I'm just learning all this stuff.. just assembled my bike stand last night.

My concern was that this bike is so obscure, and the rims are unmarked. I'm just not up on how old rims interact with new tires-- I know some older rims are just not meant to take the higher pressure tires they have now, but I'm not sure what the limits are. I did put new rim tape in at the same time.

I'm glad I had someone show me how to muscle the tire in without pinching the tube. I've ridden about 4500 miles (if the odometer on my old bike is right) and I've never had a flat. Never did my own maintenance before, so I never took a tire off.

Girl's gotta start somewhere, y'know.

Then I'd suggest you read this webpage:
http://www.sheldonbrown.com/tire_sizing.html

and generally, the whole website maintained by Sheldon Brown has proven to be the best, most informative and precise resource on everything-bicycles. As you grow in your bicycle mechanics skills, you'll learn to aprecciate it ever more.

I don't understand this reference to 'beads' - what's a bead as it pertains to bicycle tyres?

Bead
A hoop, usually of heavy steel cable, that forms one edge of a tire. Sometimes made of Kevlar ®; for lightness and foldability.

Found in: http://www.sheldonbrown.com/gloss_ba-n.html

[QUOTE]

Sheldon's site is pretty good, but for now she needs to continue with that maintenance class like she has been. Sheldon will come later when she's had a little more hands on experience!

Solveg ~ you go girl

Absolutely no reason why the OP shouldn't read Sheldon's site. Should she continue with the class? Of course. That doesn't mean she's not yet capable of understanding what Sheldon "capt bike" Brown writes. Youn underestimate people.

That's what I think, anyway. And she'll make her own mind, regardless of what a bunch of anonymous smartasses (me included) thinks, because she has free will and reason.

Ive done it more than once....lol

I had this happen the other day when airing up a wide 32c tire on a narrow 15mm (internal width) rim. That combination just barely squeaks in to the allowed category on Sheldon's tire/rim chart. Anyway, just as I had finished airing the tire up I heard it make a creaking/popping sound as it was coming off the rim so I quickly deflated it before it had a chance to blow all the way off and ruin the tube.

The next time I paid even more attention to make sure the bead was seated evenly all around the tire as I added air a little bit at a time, then I let both new tires sit for a day before taking the bike for a short ride. So far so good!

Question: How much air did you put in the tire? If your rims are old enough they may not have a hooked lip on the inside of the rim to capture the bead. They very well may be straight sided. If that's the case then you shouldn't exceed much over 70lbs of air pressure.

I've been to Sheldon's site. That's where I learned all about my really early uniglide cassette (thanks to the link from you guys!)

I read this forum and Sheldon's site a lot, but I'm afraid it's true that a lot if it gets put away in my head for "later". Sometimes I read about one topic and it leads to another, and then I've been reading for a couple hours. I'm trying to learn the stuff that will keep me from screwing up right now, and the more advanced stuff I just don't even bother trying to understand until I'm ready to try it. Just understanding the jargon and the history of the components is tough right now.

But because of reading this forum and Sheldon's site, the things we learn in class are more meaningful to me, so that I know exactly where they fit into the big picture.

For instance, even though we learned about the BB, because of this site I knew that it meant several expensive tools and a good chance of screwing up your bike in a expensive way, so I slotted all that away to do when I'm more experienced. And I also learned that, no matter what everyone says, using a torque wrench on a crank bolt is the best way to go. And I've also learned from you guys that putting Lock Tite on things requires a bit of knowledge and restraint, or access to a blow torch! These are the things that have kept me from screwing up.

Thanks guys and Sheldon!

But it's nice to have someone there, hands on to show you how much pressure to use, and to deal with all the idiosyncracies you might run across with an old steel bike.

I'm working on 3 of my own bikes right now, an 81 SR, a Bridgestone 200, and a Klein Stage Comp. I won't even touch my Atlantis, at this point. I'm going to take the beginner class once more with the Stage Comp because the derailleurs are so different and I have some questions about wheel truing, still. Then I'm taking a complete overhaul class with the SR, and then a wheel-building class.

BTW: the hard part of Sheldon's site is knowing what's up there and how to find it. It never occurred to me he would have tire/rim combos up there.

I remember the first time I replaced a tube on my road bike. It took me the better part of an hour and I was almost in tears. I just COULD NOT get the darned thing back on the rim. I almost swallowed my pride and took the thing into the LBS. I finally got it back on there. I'm much better at it now. I've mastered the technique of using the heel of my palms to push that last bit up on there.

As I am a part time teacher in a mechanics class I feel it's good for you to continue your classes. A student has a better grasp of things once they see how everything works. Have fun!

Another Tom Robbins fan huh? Don't think there are many of us about.

Solveg- This is a "hook bead" rim (from Sheldons site). The flanges on the edge (and air pressure) help hold the tire bead from pulling out. Other rims are "straight wall". (U) They won't handle as high pressure, since the only thing that holds them on is the tire bead strength/stretch resistance.
http://www.sheldonbrown.com/images/b...t-diameter.jpg