4900 miles on my 500. When riding I was going bout 45mph and had to let go of my handle bars to zip up my jacket. I was in 6th gear. And I noticed my handle bars start to shake and my front wheel move from side to side. Not fast but enough to get my notice. Then I tried it again around the same speed but this time popped it to neutral and left my hands off longer. I noticed that the side to side shake would get less shakey and the front wheel would gradually start to sway longer and farther from side to side. Like the pattern would start off small and get wider the longer I kept my hands off the bars. From 45 Mph down to 20mph the front tire was only tracking maybe 2 inches side to side by the time I got down to 20. Does anyone know what causes this? My 250 I used to own coasted straight as an arrow when I let go of the bars in any configuration.