[progval]

Torque = distance×force, so force = torque/distance, so force is linear in 1/distance.

[roel_v]

Thanks, that makes sense. Once you start thinking about it, it's obvious (e.g. F can never go to 0), turns out I've always had a wrong mental model of how the length of a lever influences the torque (beyond 'longer lever = more torque' of course).