Low speed wobble on decel.........Not to argue with XSLeo, he is right about the wobble leaving after new tires.
If you were to draw a line down the forks to the road surface, the point where the tire meets the road is behind that straight line down the forks, that's what causes the castor effect. Ever watch a castor wheel on a shopping cart wobble back and forth? That's what's happening on a motorcycle. At 160 pounds I can get that wobble to start on any bike, whatever its condition. One small pebble on the road or a speck of dirt on the tire can get this wobble started too.
Yeah, check the bearings, tires and chassis. No need to change the tires every time this happens, get the safe wear out of them, keep your hands on the bars. The low speed wobble on decel is just in the design of the bikes. Keep your hands on the bars and you won't even notice it.
And, of course worn tires and bad bearings make it worse. Gain 50 pounds and it may never happen too.
Scott