I just bought a mountain bike yesterday. I also bought some accessories (pump, lock) and I hanged the bag they were in, on my steering wheel... Unforunately the bag touched the front wheel, got stuck between the brakes and the rim. I eventually stopped the bike after a few seconds, but the pump I was carrying in the back hit the spokes on the front wheel. As a result, the front wheel was a little bit warped (I tested it and while it was turning I could se it was not aligned and it periodically touched the brakes). I returned the bike to the shop and they aligned the wheel. Now I still can notice a slight warp but it is a lot better than before.
I also spinned the rear wheel and I noticed a similar wobble by watching the gap between the rim and one brake pad.
Is a slight wobble acceptable for a new wheel ? Does it depend on the qualiti of the wheel (my bike is dirty cheap). Should I worry abou the wobble?