I never figured it out. I had a roller brake on the rear of a commuter bike with a Nexus 8R35 hub. I greased it carefully using Shimano roller brake grease, it seemed as if I could never get any modulation with that brake, it was all on locked-up or not stopping. Before I knew it, grease was coming out of the brake from every pore. After several years I gave up and sold the wheel with brake. I never felt as if the Shimano roller brake was a viable option if the rider exceeds 10mph.