Cycle Sport America did an encouraging story of Daniel Teklehaimanot, of Eritrea, a few months back. He's on the Swiss Chervelo club.
In the early post-war period North Africa fielded a national team in the Tour.
As with any sport with a geographic center (western Europe), cultural acclimatization is a problem. For example, I cite the truncated pro careers of US riders Mike Neel, George Mount, and Alexi Grewal. With the growth of teams based outside of western Europe I believe the culture of cycling is broadening.