I am fortunate to be part of a tour cycling group where I have gathered enough information from people travelling in Africa by bike. It seems to me they have met nothing but the greatest hospitality. While there's always a risk to get robbed and maybe some areas higher than others that I would try to avoid, it is often not much more dangerous than going through the streets of any big city in Europe or America.

I do understand your concern though, but I would never do anything without being rational about it. :)