An oil change should be annually carried out or at least every 5000 km. 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 the use of the Rohloff Oil change kit is recommended.
* There will already be approx. 25 ml fluid in the hub (old oil and any penetrated moisture). After the cleaning oil is also filled into the hub then there will be approx. 50ml fluid to drain out. For this reason the cleaning oil comes in a 50ml bottle so that the old fluid can be drained out into this bottle for safe disposal.
Hint: The oil filling tube should be placed over the syringe and secured with a drop of super-glue before use.