I have a simple solution. Most dogs I have been chased by have been stray street dogs. Most of the time they are hungry. Like NeilGunton said, I too slow down to try and understand what the dog intends to do. But sometimes, its a pack of dogs, in which case it gets hard to understand their plan, because usually there isn't any. So, I just coast, and if they still keep up the chase, say something sweet, like Hello. If the attitude does not change, I take out some biscuits/cookies I keep in my pocket and throw one towards one of them.

Till now, this has worked, and I have in fact befriended dogs in neighbourhoods I have passed regularly. I have often had four or five dogs just loping along with me, just sort of enjoying the ride. These dogs keep me company till they get to the end of their territory. Even if I do not give them biscuits to eat, they still treat me as a friend.

I like dogs, and would not be keen on using pepper spray on them.