The braking force is not the only issues, with a big bike like our baggers, you also have to consider the surface area of the rotors, amount of pad contact, and cooling. The dual disk setup requires less force on a single rotor and less heat build up to apply the same stopping power. If you brake hard, you can run into brake fade caused by the excessive heat from a single disk trying to stop a thousand pounds getting soaked into your brakefluid causing it to boil. Braking was and has been by far my biggest concern when going from a sport bike to the cruiser. My 900rr weights 440lbs soaking wet, makes 120 to the rear wheel, and has dual 13.5" rotors up front with 4 piston calipers. I can easily modulate the brake force to get the rear wheel 4 feet of the ground and control the stop that way. I can also feel and control the lockup on the front wheel for panic stops without eating it. Going to the big bike, you have more mass, less stopping force, and my king has puny little single piston calipers. Top that off with forks that are total junk, you have a serious control issue. The single disk looks better for pimpin wheels, but unless you upgrade to a better braking solution, you are loosing feedback from your brakes and the possibilty of unexpected lockup or worse.

Most modern bikes run dual 6 pistons with an appropriate mastercyl. I have to say I was quite happy when HD moved to the better brakes for the late model bikes, but they still leave alot to be desired.

Things that will improve your stopping power: Good pads, good fluid that is changed regularly *water is the enemy*. Steel braided lines (reduce flex under braking and give more consistant braking* and the most overlooked, having your suspension set correctly. When I get my swapout to a late model front, I will be rocking racetech springs/cartridge emulators and have the bike setup for my weight and riding style, along with getting the brembo master cyl, calipers and rotors, or I will have some adapter brackets fabbed up and slap a set of dual 6 pots from a sport bike on their with the appropriate Mastercyl.

 

Ridean 08 and try the brakes, I think your opinion will change.

 

My fat boy had a single rotor and caliper and it stopped pretty good, I am sure that a single disc set up and a six piston caliper will be just fine...

 

Ok, so I will upgrade my caliper to a six piston. Performance Machine, or a Hawg Halter, or? And will a maybe a larger diameter rotor to have more braking surface.