dual disc question

I have a 78 kz650b2.....and I want dual disc brakes on the front....the lower leg on the right side has mounts for a caliper...is this possible with the spoke wheel?? I have seen dual disk setups with the cast wheel.. Will the dual brake parts off a kz650SR work, and is the rotor the same for both sides?? Is there anything else that will work for me??? thanks

easily done. yes those parts will fit. now you need to decide do you want sintered metal pads or organics.metal requires a different piston in the caliper...heres a shot of my kz650b2 with duals installed...steve

You'll also have to decide if You want the calipers in BEHIND the forks,or in FRONT.I did the upgrade to My bike,and I had to switch the forks around in order to get the calipers to the backside of the forks.It's entirely up to You.I did it because I thought it looked cleaner.I also had to change My speedo cable to a longer one,because the original was too short after I did this.
You might also have to change the master cylinder.I believe the one for a single disk is a 1/2 inch,and You should be using a 5/8,but don't quote Me on that one.(Others will chime in)
Obviously,You'll need a second line coming from the splitter,down to the new caliper.
There should be a cover on Your hub on the side where there is no caliper...remove that,and it will expose the holes for the other disk.
It WILL work,but You have a few things to do.

I believe this article discusses everything you need to know about dual discs. it talks about using a 1/2 inch MC vs a 5/8 MC in there somewhere too.... just reread part, if you stick with the 1/2 MC you will have very touchy brakes, you wont have to pull very hard to get a lot of stopping power
Scott

Post edited by: 77KZ650, at: 2006/11/29 21:23

are there any other calipers and rotors beside what comes on a kz650 that will work?? I guess what I am saying is that this specific caliper and rotor was used on a lot of different models....I guess

Post edited by: unkle fester, at: 2006/11/29 22:54

I used KZ650SR drilled rotors on the front of one of my 750 twins, so I guess the 750 twin calipers and rotors ought to work on your 650.

Hey Unkie, I am in the middle of gathering the required parts to do the same conversion to my Kz650B2 (mines red). The rotor is the same 4 bolt, solid undrilled item used on the later 900's, 1000's and 750 twins. Our bikes have the caliper mounted behind the left fork leg so the '78 650c/sr is a perfect donor for a RH caliper. You can use one of the earlier calipers (77) but the bleeder valve is in a different position than the later stuff. I have read on here regarding the master cyl issue and have decided to try my orig MC using the twin discs and see what it feels like. I have had no luck finding a dual out splitter for the brake lines, so I am just gonna mount both the lines together and use a longer through bolt. I will be posting pics of mine during work soon.

good luck!

Ray Kelley

SpokeWheel650B wrote:

I have had no luck finding a dual out splitter for the brake lines, so I am just gonna mount both the lines together and use a longer through bolt. I will be posting pics of mine during work soon.

Ray Kelley

I did the same thing(used a longer banjo-bolt to accomodate 2 lines),and it's been 2 seasons with no problems to speak of.
It WAS,however,a real P.I.T.A. to get the new system bled,but once I realized that I had to remove the calipers from the forks...hang them with string,tilting them stightly,and bleed them THAT way...everything works like it should,with great stopping power.

If you look at a 77650c you will see that kawasaki used the double banjo bolt , I too am in the middle of this swap on my 82 KZ750 twin, I tried to mix 4 bolt rotors with 6 bolt rotor forks , another word tried to use 750 spectra forks with my stock wire wheels 4 bolt rotors , It wouldnt work with out get some machine shop time in ,, If the axle is on the bottom of the fork use those style wheels and calipers , if the Axle is forward on the Forks use those style rotors and caliper ,, ( Later style ) ,,My 82 twin uses a special fork with the caliper mounting holes slightly forward so it will match up ,, Most forks mounting are straight not forward ,, I think Steell has the best plan get the parts from the same style of bike ..The splitter depends on what syle master Cyl you use , Brake swith mounted on the brake lever or pressure swith mounted on the lower triple tree .. add in you might have changed handle bars so now need a straight mount with a micro swicth ,, I found that the KZ550 is just what you are looking for ..

if you do find a splitter make sure you run down to the hardware store and get the right length bolts for it. the old ones will be too short...steve