jack pot 

i put a new rear tire on my fixed . when i put the wheel back on the bike i neglected to fully tighten down one of the axle nuts. i had semi tightened it when i was adjusting the chain tension. the nut was tight enough to handle a flat ride but when i came to a medium grade it gave way and canted the axle locking the wheel against the horizontal part of the rear triangle. luckily i avoided a crash. after i repositioned & TIGHTENED the wheel i spun it and noticed that it is slightly ( enough to notice when i flip the bike and spin the wheel) OUT OF ROUND....... the wheel is a 700c ...... 1 could jamming the wheel against the frame cause it to be out of round ? 2 how much out of round is unsafe enough to get a new wheel ?

Andrew R Stewart 

A badly jammed wheel/tire against the chain stay could cause a rim to become out of true laterally. If bad enough some radial out of true will result. But I suspect the wheel or tire was already out of round radially before the wheel cocked in the drop out and jammed against the stay.

The most common reason for the tire to look out of round in a localized spot is from it's not being seated well. Either a low spot from the tire bead being too far in the rim or a high point when the bead is not overlapping the rim's interior fully. The latter is often found at the valve area as the base of the valve can interfere with the tire's bead ability to seat down onto the rim bead shelf. Otherwise known as a tire hop.

But the rim could also be somewhat egg shaped from poor assembly or an incident. A common rim problem is a local flat spot from a pot hole impact. It should be evident by watching the rim's side wall edge passing by a stationary item, like the brake pad. Does the rim seem to undulate up and down? If not move your view to the top of the tire, does it seem to radially move up and down? A piece of masking tape stretched across the stays and just grazes the tire helps in this view.

As to how much of either is too much depends. Rim flat spots are generally not as bad except for the resulting braking affects. A tire that isn'yt properly seated can lead to a blow out which if happens at the wrong moment can be a real safety issue. Andy

Pop N Wood

Wonder if you bent or broke the axle?

A quick spin in a truing stand will tell you if it is the rim or the tire causing the visual issues.

madpogue 

First, is the WHEEL out of round, or the TIRE?

jack pot 

it was the tire. i fixed it. even a blind hog ...

Andrew R Stewart 

Good job and thanks for the follow up post. Andy