Brake Bracket:
First note: The ZZR brake caliper is a direct bolt on to the 636 brake bracket. You do not need a 636 caliper for this project.
Once your spacers are the appropriate size and installed, measure the space left on the right side of the axle. This is how much room you’ll have for your custom brake bracket. From my measurements it is ~9mm or ~3/8”
As you can see in the pics, the 636 bracket is much too wide to fit into this space. There are two possible solutions to this, both of which involve making a new bracket.
The first has been done by a member of this board, but –no offence meant to him- I wasn’t comfortable with his method giving enough strength for this particular piece. I may be wrong though, so I’ll tell his method and mine and let you choose for yourself.
The first method is to take your 636 donor brake bracket, and grind it down to 9mm at the axle point, and to an appropriate thickness at the caliper mounting point. This would involve A LOT of grinding, and you would have to be uber-careful you got the measurements right and didn’t take too much off. Because trust me, those stinking brackets are way more expensive than they are worth.
Method number two is my alternative to the above option. Since 9mm is ~3/8” and 3/8” is a very easy size to get steel plate metal in, I opted to make a bracket out of that. I made an outline using my donor 636 bracket and had one cut in a metal shop I had access to, as well as the holes drilled.
There a lot of ways you can make one of these, using anything from an angle grinder to a torch to an automated torch (which is what I fortunately had access too). The biggest difficulty is that the hole for the axle is roughly 1” in diameter, and trust me, you can’t just pick up a 1” metal drill bit at your local hardware store. Its best if you have a machinest do it for you. It’s a fairly simple project for them.
NOTE: 1” is actually slightly too big of a hole. You will want to use calipers to get an exact measurement. Or you could use the ghetto caliper method: tighten a crescent wrench around your axle, remove the wrench, measure the gap between the sides of the wrench, which will give you your axle diameter.
Back to the bracket I made:
After cutting out the bracket and drilling the required holes, the bracket was not completely satisfactory because when mounted on the axle, the other end would hit the swingarm and not allow the bracket (and it turn the caliper) to be mounted perfectly parallel to the rotor. This would cause bad things to happen, such as crappy braking and uneven brake pad wear. So out with the grinder again.
To make the bracket line up perfectly parallel to the rotor it required some metal to be removed from the right side of the plate, on the end that has the “bracket slide guide”. Once this is done, it will allow you to put the bracket on the axle, and have it line up parallel to the rotor, providing even contact between the brake pads and rotor.