I've been thinking of getting back into cycling again - but after 12 years, I can only imagine the amount of pain that I'll endure while whipping this relaxed body of mind back into form.
We live about 25km outside of the city - and I've often though how awesome it must be to live in the city center, or anywhere around Table Mountain in fact. Compared to the mountain and ocean routes of the Cape Town area, our Northern suburbs residential roads are plain boring.
If you're visiting Cape Town, consider hiring a bike - you'll see far more than you would by car, and cover far more ground than you would do walking. You could also consider doing a cycling tour - it's probably safer and you may even make a few new friends.