Converting to Dual Front Discs....Master Cylinder?

[guppymech]

Hey, I've got a '84 FXE that uses the typical mid 80's black single piston caliper.  If I convert to dual front discs using another of those stock calipers, will my 5/8 master cylinder work okay?  I'd like to keep it all stock H-D parts of the era.

[76shuvlinoff]

I don't know what the piston area is on the calipers you are looking at so this is not apples to apples.

I installed a 2000 and up front end with 2007 dual 4 pot calipers on my 76 FLH. Front rim is off a mid 2000s Road King.
I was already running a GMA 5/8 master cylinder and it works great. Two fingers.

[JW113]

Guppy, 5/8 is what they should have been using since day one on dual disk set ups. But then, HD does not believe in low effort brakes, especially on the front. They believe in passive anti-lock brakes, i.e. you need to be Hulk Hogan to squeeze the damn lever hard enough to lock the front wheel. Notice that on the newer models, the master cyl piston size has come down somewhat. But nothing even in the ballpark of what you would find on a Japanese, Italian, or German bike. Go with you're 5/8" m/c, I think you will like it.

-JW

[guppymech]

Shuvlinoff and JW, Thanks for the info!  5/8 it is.

Tom