I am pretty big guy 250lbs without gear. I use it as a practice bike for when I am not at the track so I tend to brake hard enough to bottom out the forks. I needed springs at the very least and extra dampening. This would help me prevent me from getting in trouble while trail brakingI found the standard suspension to be very good for the type of bike that the Duke 390 is.
It rides well over rough roads and still seems to handle well on the smooth stuff.
How will this kit improve the bike?
Ah right OK l can see why you would want to upgrade the standard setup. The standard units are non adjustable so if the forks are bottoming out there’s nothing you can adjust to improve it.