Perhaps of interest to others... I machined a spacer (1.5 mm) for a Klamper caliper to allow use of a Hope vented rotor (3.3 mm) on our Rohloff hub and it all works well. Hope was not interested in making a cabled caliper and Klamper was not interested in modifying their caliper. I like the Klamper caliper because it is strong with no plastic parts susceptible to melting and easy to disassemble for cleaning. I prefer to not have hydraulics on a touring bike.
We tour in areas with steep descents at times on a tandem loaded with camping gear, etc. I have always been keen on more braking for heat dissipation, so this will help.
