Fixing flat and truing the wheel?
 

Just recently I had flat tire on my rear wheel. I replaced the innter tube and put everything back. On my first ride I hear "sheesh ... sheesh ... sheesh". I stopped, lifted the rear wheel from the ground and turned it by stepping on the pedals. The brake pads are touching wheel's rim and the wheel seems going slightly from side to side. Is it possible that while fixing the flat I accidently brought the wheel out of its delicate balance? When I lift the wheel, lean the bike on one side and turn the wheel -- the "sheesh ... sheesh" sound is more pronounced.

bagel007;

Did you check to make sure you pulled the wheel firmly back in the dropouts? I had the same prob once & simply loosened the quick release & reseated the wheel & everything was good to go.

Greg

+2 :thumb:

I doubt you put it out of line while working on the flat. It's possible that it got mis-aligned while riding with the almost flat tire before you noticed it. Or if it's only slightly out of line it's possible that when you repositioned the wheel it went back slightly to one side or the other and now rubs.

Step one, loosen and reposition the wheel with the bike on the floor and held straight up, letting the wheel find it's home spot, then retighten the QR or nuts. (If you have horizontal dropouts, you might have to hold it centered between the chainstays).

if that didn't solve it, and the total side to side wobble is less than 1/16" try re-centering the brake. If the wobble exceeds 1/16", consider having it re-aligned or DIY if you feel up to it. Here's a helpful site if you want to get started aligning your own wheels. My advice is take it slow and stay within your comfort zone.

The wheels need to be on the ground when you tighten the quick release.
And your wheel needs to be trued.
And your brake caliper may be off-center.

It cannot be the case. I clean the chain after each ride. I would've noticed that the the tire is deflated, even partially.

I'll do that even though I've tightened the quick release while the wheels were on the ground.

How can I do that? I don't have a workstand, so I'll have to do it with the bike upside down and turning the wheel with pedals. It's impossible to hold the rear wheel in the air and working on the brake. I'm not sure I can fix the problem, but at least I could do the wobble measurement ... only if I knew how to do it and had the right tools for it. Any external link would be appreaciated.

You missed my point. Tires don't instantaneously get flat, and you don't immediately stop. You're still riding as the tire gets soft, or in the event of a blowout it takes some time to stop.

However, if the wheel is out of true by less than 1/16th or so, I'll bet it's been that way, and became an issue because of repositioning.

Either put the wheel home by closing the QR on the ground as others and I suggested, and if necessary re-center the brakes for that position, or manually center the wheel to best clear the brakes and close the QR there. The second approach is less desirable because it means re-centering the wheel every time you open the QR.

You don't need a workstand. You can either have a friend hold the bike, hang it someplace by the saddles nose, or flip it upside down using books or bricks to support the handlebar on either side of the stem.

To measure the wheel's runout (wobble) spin the wheel until the highest spot just touches the brake, then slowly continue spinning it until it's farthest away. How wide is that gap? If it rubs over a long length and the rim actually pushes the brake away, estimate and add that amount.

Centering a brake is also fairly simple, but before we go there, lets find out what the wheel situation is.

I believe mine are "vertical" (see the picture). Right? In that case, when I open the QR clamp and turn the nut on the oposite side, the gravity should take care of bringing the wheel to it's home spot. I'm sure I can hold the bike in horizontal position with the wheel on the ground while securing the wheel with the QR clamp. Actually, during the previous year I removed and put back the front wheel numerous times w/o the problems I'm having now with the rear wheel.

It's not delicate. Consider the hammering it receives when you ride it.

So, almost certainly not possible unless you jumped on it. Most likely you put it back in a little crooked. I guess there's an outside chance of some sort of weird interaction between tyre pressure and spoke tension going on, but highly doubtful that there'd be any difference between your spoke tension with an inflated tyre pre and post flat fix.