I had new tires and sprockets put on my bike. I've only had it for short while, bought bike used. Took it on a couple trails before putting the new tires/sprocket/chain on (had shop do it). When I got it back, my friend said there was a slight wobble to the rear tire, I thought it was just tread on tire (it's a 70dirt/30road tire). I never noticed this before and was first time I had someone riding behind me with this particular bike. I had them ride it and I did notice that the rear tire wobbled a litte, more so when going slow but less if any when going faster.. I couldn't really feel the difference when riding it to be honest - but needs to be fixed as it'll cause uneven wear. Question- is this because shop didn't balance tires ( I called shop and they will look at it again) - or something maybe more severe to frame / swingarm that could cause this? Its an older 2004 WR450, was ridden hard but kept up , guy would grease the bearings, use synthetic oil, etc. But think he was a racer so the bike has probably taken a few hits. Thanks for any input as to what is most likely causing this.