i'm needing some ideas. does anyone know if there is a company that makes a caliper for a sprotor that is 4 piston, but two of the pistons operate seperately from one another. meaning that a foot brake operates two of the pistons and a hand brake operates the other two. two seperate break lines running into a single caliper. or maybe know of a way to modify a standard 4-piston caliper to get what i'm looking for? or maybe even some sort of auto throw over t-valve that would prevent the unused master cylander from being backfed? i'm building a late 60's early 70's chopper style bike and i'm a little hesitant of strictly running a foot break with the wife on the back of the bike. if i were going to be the only rider, i wouldn't be as concerned about it. any help, insight or ideas would be ghreatly appreciated!

 

Dude on a bike there are so many ways to get decent compact brakes on both wheels and keep it clean it's unreal and if it's safety your concerned about toss your whole idea out the window fast it's way more complicated and involved than just doing a simple small disk up front and whatever on the rear that's a lot of crap & lines your talking about . Take this from somebody who actually ran the tiny *** 8" Hurst Airhart go kart disk brakes on 10' long choppers in the 70's , just you do what you want . Your packing someone your responsible for them do it right .

Be happy to bounce ideas with you I do custom brake mods all the time from used rice rocket stuff . That stuff tends to be small , cheap and works .

 

I believe it would be wise to heed TwiZted Biker's advice and run a front brake.
Spool front wheels look good but...
Also, splitting the function on a four piston caliper would make it a much less powerful brake unless you are operating both master cylinders at the same time.
And under certain conditions, there could be a serious loss of stopping power if/when the pads/disc get wet.

 

{EDIT}
Double post again! Is there a problem with the "Quick Reply" function?

 

No matter how many lines or master cylinders you run to a single caliper on the back, you are not going to increase stopping power. People will argue over the percentage, but the front brake does way more than half of your stopping power because of weight transfer. If your chopper just has to look cool, with the" no front brake" look ...cough up the bucks and buy a 360 brake...cheaper than a funeral or one day in the hospital.

http://www.360brake.com/photogal.html

 

GMA makes a small very clean disk set up for springer frontends that can be easily adapted to others and they look very retro if done right .

This is the rear set up I did for mine , had some stuff lying around and was bored .