mkras17

I was riding last night and went to shift gears and it locked up and realized the tire fell out, the derailluer seems to be ok i got the tire back on yada yada and a few pedals later it fell off again. Can the quick release have gone bad? It feels tight but I guess doesn't get tight.

FBinNY 

From the fact that you called the wheel "the tire" I infer that you're relatively new to this and suspect that you're using the QR incorrectly.

It's a cam system which is adjusted by turning the nut on the right side but once adjusted, opened and closed by flipping the lever. It stays closed because the tightest point is just before the lever closes all the way parallel to the frame, so be sure it's always closed all the way.

Open the lever, and hold it straight out, (half way between open and closed) while setting the tension with the nut. Correct tension is about when the lever begins to have resistance at this half way point, and closing it all the way requires a decent amount of force, but not so much that it's hard to open again.

BTW- don't close the lever directly over a frame tube, but off to one side so that you can always get your fingers behind it to open.

For future reference, the tire is the rubber part mounted on the rim, which along with the spokes and hub comprise the wheel.

mkras17

I know how to work quick release systems, bikes aren't the only things with them, I have used them before. I did do that and still after a few pedals it comes right out.

FBinNY 

Please don't be offended, I'm trying to help you without benefit of seeing what may be happening.

QR's don't wear out but they do come out of adjustment, so check that it's closing with a decent amount of resistance. It's compression from the QR's cam action that holds the wheel in place, and it cannot be tightened enough by holding one end and turning the other. It's also possible that the wheel isn't fully pocketed into the slot in the dropout, or that something is keeping the QR ends from pressing fully onto the dropouts.

BTW- if you've taken the QR skewer off, make sure that the two conical springs on each end have the narrow end toward the axle as in Nut[>==axle==<]Lever. It they're reversed they can keep the wheel from being secured properly.

cny-bikeman

Well, the cam mechanism does not wear out but I have previously seen the threads on the skewer worn enough so as to no longer hold the acorn nut securely. Also can be a problem if you mix two different threadings of Q/R. Happened some in the old day I don't know that would be an issue with parts of more recent vintage. The only other thing I can think of that FB did not cover is the axle sticking out too far. That would only happen if you had recently overhauled the hub and left out a washer..

go1dens4

+1

Homebrew01

FBinNY pretty well covered it. Sounds like the QR is out of adjustment.

AndrewP

Check that the end of the axle doesnt extend beyond the dropout. If it does, the QR only pulls the acorn onto the axle which prevents it clamping the dropout.

Al1943

Also if you have vertical dropouts be sure that the wheels are on the ground when you close the skewer. If you have any doubt, open and close the skewer with the wheels on the ground.

fietsbob

the effort of closing the QR lever should leave an impression in the palm of your hand,
it should not be easy.
the axle should not be as wide as the outside face of the dropouts.

Wordbiker

Check to see if the skewer has rusted inside the axle.

If it's seized, it will feel adjusted but will not clamp both dropouts. The fix is pulling the skewer (sometimes a few taps are required), cleaning, greasing and reinstallation. Some lube on the cam lever pivot will also give more closing torque.

cranky old road 

It's also possible to insert the axle so that one end is placed on the interior face of the dropout rather than in the dropout slot. When it finds it's way into the slot the quick release will be loose.