I've recently bought the wife an 883 SuperLow and we are having issues with heavy vibrations on deceleration.

You can feel it as soon as you back the throttle off. It feels like the engine is carrying more revs than it should and once you slow down enough there is a really heavy vibration that kicks in. It's really odd.

She's got a heavy breather and V&H race slip ons.

Any clue guys. It's got me stumped.