Topic: Master Cylinder Recommendation for Dual Disk - with brake light switch

[Kong]

I've searched through the various posts on doing a dual disk conversion and they mention finding a master cylinder off a GoldWing or similar but very little else is said about them.  There's a bit of an information void.  That said I'm not much worried about finding a compatible master cylinder at a reasonable price on E-Bay but I have one additional requirement for one.  I want one that has a built-in brake-light switch, either mechanical or pressure, I don't care.  This will allow me to use the original junction block to run hoses to the dual disks by removing the brake light switch from it and putting a Banjo in its place but also to keep my front brake light function - something I want not only to stay legal but for safety purposes as well - using whatever mechanism is built into the new master/perch/lever.

So, anyone got any recommendation?

[Ricky_Racer]

Kong, you could also us a late "F" junction or use a dual line banjo in your current fitting. RR

[Motoguy23]

I got this really nice MC for a GL1000 with the light switch on it and it was only like $75 off of Ebay.

[GammaFlat]

The K8 master cylinder has an integrated mechanical switch.  I've heard of plenty of folks driving dual disks up front with a standard master cylinder.  Other than that, there are MCs on ebay that have a rectangular reservoir which have a mechanical switch.  

[MCRider]

I'm using one from a VF500. "5/8" on the body meaning a 5/8 piston I think, for duallies anyway for sure. It has the hose takeoff on the front so more room on the handlebars for hose to tach clearance when using narrow bars. It has a mechanical switch. That answers your question.

However, I didn't want the extra brake switch wires showing, and to keep the stock pressure switch I routed my hose (singular) to the left caliper, then caliper to caliper over the fender. I've seen some sport bikes, Suzukis I think, plumbed this way.

[GammaFlat]

The length of that line looped over your fender looks dead nuts on.    Excellent!  Did you have any trouble bleeding the left side? 

[MCRider]

The length of that line looped over your fender looks dead nuts on.    Excellent!  Did you have any trouble bleeding the left side? 

This was the same setup I ran on "Phaedrus I", you're looking at Phaedrus II. So its been tried and tested. I do not recall any problems bleeding the lines, what you see hasn't been bled yet. I would bleed at each connection and I may have held the caliper up if need be, but I don't remember any problems.

Thanks on that line. Now here's the strange part. That line originally went over a stock fender on a 19" wheel. What you see is an 18" wheel with a CB350F fender, also an 18". Now that line fits so close, looks like it was made for it. So I can't remember how i got it over a 19" fender. Maybe it was stretched real tight, or I had a taller adapter.

It was so many years ago i took Phaedrus apart I just don't rememeber. And there have been many things like that in this rebuild. Strange.

[turboguzzi]

i would recommend you go for a 14mm MC, a 5/8 (15.8mm) might feel a bit wooden and not give you the full braking potential of a twin disc setup.

TG

[MCRider]

i would recommend you go for a 14mm MC, a 5/8 (15.8mm) might feel a bit wooden and not give you the full braking potential of a twin disc setup.

TG

Thanks, I'm not married to this, just liked the profile.

I did have a master from an unknown model Kawasaki from a salvage yard on Phaedrus I. I knew nothing at the time and only a little more now. The proprietor said it would work fine and it did. It had a 5/8 on it's body as well. There are likely other small variables like the lever leverage and such.

So your concern is noted and I'm ready to change if need be. The one in the photo was virtually free from the same salvage yard (CRC2) has been sodablasted to a natural finish, but i did nothing more waiting for a test run, in case i didn't like its feel.

Apologies for the thread jack. But i do think we've given Kong something to work with.

[Silverback]

I like the Honda V65 masters (as pictured). There are two variations; one for swept bars and the other for standard. They are also 5/8. I happen to have a spare vf500 master that I could let you have for cheap. The lever is bent, but can be bent back or replaced.

[Kong]

I appreciate the offer but I just picked one up off of E-Bay a few minutes before coming back here to check in.  Got one off some Kaw, I'd have to look to see which model, but it had a switch and wires.

[turboguzzi]

sounds a bit late for this, but there are also different angles between reservoir tops and handelbar/lever line.... some are tilted to fit sports bikes with clip ons. hope you picked the right one for your build...

[Kong]

The one I got was for a KZ440, it appears that the handle and reservoir are on the same plane.  I think that should work, but if not it will be just one more part hanging from a nail I guess.  As it is now I've got about half a wall that's got a regular curtain of odd length hoses, belts, cables, and assorted wiring looms - this could very possibly be another addition.  Le'ts hope not though.   

[Fritz]

Well, maybe it's too late, but my 550F has got the dual disk setup and the original master cylinder with a double banjo bolt connection at the stock break switch.

It's braking and it's braking well

[fasturd]

I have bought and used Nissin 14mm master cyl set ups with great results on 750s and Gl1000s very popular upgrade on early gold wings. Makes 'em stop with 2 fingers. A GL1000 stock master will work great too if you want it to look vintage.