I fabbed a rear brake reservoir from some 1/2" aluminum tubing, extra Rizoma outlets, some o-rings, an M8 aluminum bolt, an adel clamp and some zip ties:
For the outlet, I tapped M7x1.0 threads into the tubing, and for the cap I tapped M8x1.25 threads. Some Tygon, zip ties, o-rings, adel clamp and viola!
I let it sit overnight and there were no leaks.
If you're careful, you can do the swap without bleeding:
Installed:
Brakes work fine. The volume of the tubing allows for sufficient amount of fluid, and I left the "reservoir" 2/3 empty to allow for fluid expansion. This should be fine as I only use the rear brake for low-speed maneuvers, finishing stops and while sitting at traffic signals.
