Very sorry to reopen this subject six years on from the last discussion but it may be a useful mention to some that Zwartkops os currently open to cyclists from 17h30 to 19h30 on Tuesdays and Thursdays, with alternate directions on the two evenings: clockwise on Tuesdays and anti-clockwise on Thursdays.
The R25 fee can be settled with a card and a 10-ride book of tickets is also available.
Happy Laps!