The original question and most of the answers deal with generality.This should be basic physics. If we concentrate on the hydraulics, it is simply moving fluid under pressure creating work.


The master cylinder has a piston or plunger that places a force on the fluid. The piston has a set surface area. At the other end, we have the caliper with pistons. If you remove one caliper, the surface area of the pistons in the calipers is now cut in half. To achieve the same total clamping force, you would have to squeeze the brake lever a lot harder.


Changing to a 6 piston caliper would help. to have the same feeling as the stock two caliper system, the single caliper would have to have the same square inches of piston surface and the brake pads would need to have twice the surface area as the two caliper stock system. This works to a point.


The repeated use will build heat. That is the entire function of a brake, converting energy of momentum into heat. The single caliper may or may not dissipate heat as well as a factory twin rotor system. It depends on the mass, material, surface area and shape.


I guess there are systems out there for the conversion. Does HD offer a conversion kit? If so, that kit would probably be designed to get the job done correctly, not just improved looks at a risk of safety.