Namibia is well cool and apart from the major road (s) is mostly hard packed dirt .
Must sees are Sossusvlei ( red dunes ) , there's another in the north where the world's largest meteorite can be found . Also Fish river canyon and for me the weird aloe trees that grow in a small forest in the south .
The road into the red dunes in the national part is very sandy so might be a bit of a pain on bike . I went into the park as far as the last building which is a shop and where you pay your fees and hitched with some nice Belgians in a 4x4 .
Also this park is closed at night so if you are a keen photographer and want those early morning shots you must stay in the park overnight . Space is limited in the park so arriving early may help .
The road from walvis bay to Sessreim (sp?) is longish without petrol , around 300km . There may also be some distance between gas stations in the north , past Etosha .