Well I'm not African so I don't know.
I'm thinking that in the west we either have very cheap bikes that aren't really designed for long term use, and more expensive bikes tend to use fancier parts.
Off the top of my head. Steel frame, can be repaired / modified with any old welder. Designed so it can be taken apart with the minimum of generic tools. Standard bearings, brake blocks etc (probably brake blocks that you can shove some piece of old tyre in).
Front forks and the crank require special tools to remove. I assume the free wheel assembly would be the same. I don't know if it would be possible to modify these to be serviceable with basic tools, the point is an African could probably work out how to fix a bike, the issue would be affording tools and spares, and availability of those tools and spares.
Have made a few suggestions above. Obviously I don't see Africa as a uniform continent, but extremes of dryness and humidity can be found in different parts, in some areas roads are bad and so on. Also good places for bike locks (which we all need), maybe water bottles, cargo features and lighting (since some roads will be unlit (again a general issue.)
Sounds like a Dutch bike would work well
> Off the top of my head. Steel frame, can be repaired / modified with any old welder. Designed so it can be taken apart with the minimum of generic tools. Standard bearings, brake blocks etc (probably brake blocks that you can shove some piece of old tyre in).
So basically just your average cheap crappy Halfords Bike-Shaped Object type "bike"?
Yeah, that sounds about right. I assume such bikes, parts and tools do exist. Can probably order it all on alibaba. I intend to investigate and do this in the coming years, but have to attend to other things first.