Albert..... My recommending the XS 650 wheels was because they can be easily fitted in the stock forks and swingarm of the DOHC CB 450 K with minor mods.....
I have NO IDEA if they are suitable in the Kymco forks, narrowed or not, particularly in reference to axle diameter.......and, the rear axle slots in your CB 450 SC swingarm will have to be widened (about 2 mm I believe) due to the larger axle diameter of the XS 650 rear wheel......
The initial impression you conveyed was mostly about employing different rotors, not about retaining the 41mm fork diameter and changing fork width.....
Sounds like a good project.
Do you need xs650 triple clamp details for your front wheel spacing?
i have 2 sets of 650 and 1 xs750 dual disc set I can check the tube spacing.
I'm not sure the calipers on the kymco forks are a direct swap or you need to modify too?
Honda did some strange numbers in some of the FSM's, actual caster angle is 30* (90-60=30)Looks like the cbf600 specs
Caster Angle: 26°
Trail: 110mm
I checked cb450sc in the FSM but forgot what the numbers were.
I have a bike with a front end swap off something more aggressive and hate the handling. I don't drive it just for that reason. I really like the way the stock Nighthawk handles. If I were to upgrade the front end I would probably model it after longdistancerider setup.
When I had the Nighthawk, i found it handled city street and open highway well, and performed reliably and predictably in tight lane splitting situations, and the ability to be jamming 40mph past stopped cars, hit the brakes and bounce into the next lane to pass a slower motorcycle.
edit: 450 Nighthawk caster angle 60, trail 130mm