Mr. Ron
I'll send you some photos as soon as I can find the cord that attaches my camera to the computer!

As you will see, most of the critical engineering is in the adapter plate, that joins the 4 bolt GS hub to the 5 bolt rotor. I choose the GSXR rotor (which is apparently used on many other late model Suzuki's) because the carrier is quite flat, alowing lots of meat in the adapter plate to thread the bolts into. I had to go to several machine shops before finding one that would take the project on. They charged me $300 for the adapter (aluminum of course), but did a very percise job. I ended up shiming it out a bit (2mm) to make mounting the caliper easier. I think the template is good, and could be copied perhaps a bit more cost effectively.

Like Grant, I made the carrier for the caliper myself out of aluminum - Yes Grant's is a lot nicer then mine, and I will likely redo mine a bit more carefully now that I have a design that works. The rotor cost $100 used (crashed bike) and has turned out to have a slight tweak in it. Beware, it is really hard to see if a rotor is true without running it on a lath or something - hard to do at the wreckers. I don't notice a problem at normal speed (probably because flexibility in the rotor, and the fact that it is a floating design) but at low speeds I can feel is grab slightly as the pads pass over the bend in the surface - not great. Apparently it is possible to true them up, which I will try, but I am not counting on it....

EBC sells a brand new rotor with carrier for $350 Canadian. Still, at that point you are getting into the territory of MAP engineering's Rotor that comes with a caliper mount adapter - just bolt on and go. I think finding a good, used rotor is possible (saw one on ebay for $12!) but lots are tweaked - trial and error.

A common and cheaper alternative front brake for a R100GS would be to use a four-pot K1100 caliper. Motorbins sell these ready machined. Apparently the K disc is a good mod as well.

Grant had his bike set up this way until recently - notes/ links on the 'Bike stuff' section of the web page - (on left index bar) for those interested.
Having talked with Grant about this, I still think a full sized rotor is the way to go for maximum cost benefit. The stock caliper is actually quite large (larger caliper surface area then the 6 piston Tociko and 4 piston Nissin that I compared) of course, the effective pad area is larger on the later calipers, but not by a lot. Using the stock caliper alows you to keep the stock master cylinder, which helps keep costs down.

Hey Guys, I bought a right side 4piston sumitomo caliper that is similar to the exup caliper used in Europe to retrofit the Brembo's there.It will work with the stock rotor but it was pointed out to me that when mounted it sits very low to the ground,(almost below and several inches behind the fork leg)and would be very vulnerable to rocks etc...
So the latest plan is a new EBC semi-floating rotor and new pads with the original brembo caliper. I am hoping to find a rebuild kit for the caliper and master cylinder(13mm) and put in a full length stainless line.
Hopefully this will result in half decent front brakes...
They could'nt have been that bad when they were brand new ...could they???

err, yeah... they were...

And that was when people rode slower, and there was less traffic...

Box stock unloaded they were mediocre at best, ok on the dirt for one person playing about - put two people on and a lot of luggage at highway speeds and the stock brake is a joke. And not a very funny one.

------------------
Grant Johnson

Seek, and ye shall find.
------------------------

One world, Two wheels.
www.HorizonsUnlimited.com