Update: From the organization I received some explanation about the current maintenance status of the quad bikes:
'Yes, the quad bikes are perfectly adequate for the terrain that they are used for, each quad has a new engine every two years and goes through a rigorous 15 point check before each tour, at the end of a hard Summer season each quad is stripped down and rebuilt. The dust on the tour is our greatest enemy with the heat generated by the 300cc engines in 30°+ ambient temperature and the slow 20km speed meaning that they get little or no cooling being another factor. Not being able to wash them daily (because of virtually all year round water restrictions) gives the impression of the quads being old and "requiring maintenance". Thank you for your custom and please excuse me for explaining and countering the "lack of maintenance" comment.'


At the arrival the owners received us with a friendly smile. Adjacent is a small-scale hotel where we had to register and sign a form (including additional insurance at € 3.50 p / p. Should something happen. Only a helicopter has the ability to rescue you in this area).
After this we left. In addition to the three quads we rode, there were also two others. Two Brits. Father and son.


Eventually I understood why. There were some pieces that were a bit more technical. Sort of DRZ heaven, but with an Africa Twin it would have been hard work.
The lake was worth it. The view was beautiful. A nice place to practice with the drone again and to take some nice pictures.