An oil change should be annually carried out or at least every 5000km. Through this process it can be safe to say that there will always be enough oil in the hub regardless of oil loss (due to sweat oil) and that any penetrated water will be rinsed out.
For a problem-free oil change we recommend the use of the Rohloff Oil change kit.
The Oil Change Kit consists of:
Oil change kit complete
25ml cleaning oil in a 50ml bottle
25ml all seasons oil
Oil filling tube
Drain screw with thread sealant