It is actually quite straightforward to calculate equivelant braking forces if you wanted to try and get scientific about this. From a hydraulic perspective, the force applied by each pot = pressure x area

In this case we are talking about the cross sectional area of the calliper piston, so for a multi pot calliper it would be the sum of all the pots.

It is then simply a case of calculating the braking torque. This is = braking force x radius of disk. This is not entirely accurate as the force is distributed across the surface of the pad but sufficient for now for comparison purposes.

If you kept the same disk and just wanted to change the calliper then providing the total area of pistons remains the same then braking torque would be the same.

Of course sizing of brakes is often as much about the heat dissipation as it is about braking torque but providing you are not racing around a track or going crazy with regular heavy braking then I would be confident you would be fine.

If you want to send me details of the original calliper (how many pots and the piston diameter of each pot) and disk diameter I will run a quick initial calc for you.

You haven't stated which bike you have, and most importantly whether you have ABS. If you do have ABS then there is no way you should do this mod and I would rather not be involved in this calc.

 

Apologies, I see now you have shown it as 05 so no ABS.

 

well i got a heritage softail mater cylinder today a 9/16 MC. got a stainless braided line. flushed the caliper with denatured alcohol, converted the system to DOT 5. and the braking is great, even with the stock caliper. i think it seems just as good if not better than before. and now i dont have to worry about the dot 4 junk fluid ruining my paint and peeling the paint around the resevoir lid.

 

Exactly. Put the other rotor on. I mean, why?

 

because its ugly. i dont understand why my 735lb SG need two rotors up front, but a 751lb 2006 heritage softail only needs one. i like the braking power it has now with the dot 5 heritage softail brake setup installed. ill be leaving it that way.

 

Hope you enjoy. Again, understanding the basic principles of what you have done:

IF...you are correct and the braking effect is now the same as it was with 2 callipers this means 2 things:

Firstly the pressure inside your system must be twice what it was before. This may or may not be an issue, but the seals and components inside that calliper weren't designed for that. You have achieved that doubling pressure by changing the master cylinder which, by the sound of things, probably was designed for that.

Secondly, all the braking force ultimately needs to be applied through the calliper mounting bolts. These are also now seeing twice the load originally designed for.

 

Hope you enjoy. Again, understanding the basic principles of what you have done:

IF...you are correct and the braking effect is now the same as it was with 2 callipers this means 3 things:

Firstly the pressure inside your system must be twice what it was before. This may or may not be an issue, but the seals and components inside that calliper weren't designed for that. You have achieved that doubling pressure by changing the master cylinder which, by the sound of things, probably was designed for that.

Secondly, all the braking force ultimately needs to be applied through the calliper mounting bolts. These are also now seeing twice the load originally designed for.

Finally, sizing of brakes is also often as much about heat dissipation as it is about braking force. This is especially a material issue for the pads themselves.

 

Hope you enjoy. Again, understanding the basic principles of what you have done:

IF...you are correct and the braking effect is now the same as it was with 2 callipers this means 3 things:

Firstly the pressure inside your system must be twice what it was before. This may or may not be an issue, but the seals and components inside that calliper weren't designed for that. You have achieved that doubling pressure by changing the master cylinder which, by the sound of things, probably was designed for that.

Secondly, all the braking force ultimately needs to be applied through the calliper mounting bolts. These are also now seeing twice the load originally designed for.

Finally, sizing of brakes is also often as much about heat dissipation as it is about braking force. This is especially a material issue for the pads themselves.

 

glenndyne designs makes a 16" rotor setup - 1300 bucks though

im happy with my 13" with 6piston.

 

thats exactly right, the 9/16 MC is much higher pressure, i think the caliper should handle it since the caliper is the same exact caliper whether you have a single disc sportster or a dual disc road king. from 02-07 there was only one caliper no matter what bike you have. (thats what the parts manager from the local HD dealer told me anyway) and only two master cylinders 9/16 for single, or 11/16 for dual. i now have the same exact brake setup as the "heavier" softail heritage. and the mounting bolts for the caliper are also exactly the same no matter what harley you have.