Originally Posted by wroomwroomoops

I had a nexus gear hub with a Nexave rollerbrake. It worked fine. But I now plan on building a singlespeed with a Nexave splined freehub (have you seen those?) and a rollerbrake. I'll put a singlespeed conversion on the freehub, and a Nexave rollerbrake.

Rollerbrakes are not very heavy, actually. Here, I just measured my Shimano BR-IM 31-R, and it's only about 470 g. About as heavy as a discbrake calipers + rotor combo. Maybe a few grams more, but the fact that you don't have to adjust brakepads, or replace brakepads - EVER - is a big plus in my book.