What do you do when dogs chase you when you ride?

Well, what you just did was right. Dogs act on instinct. The more you run, the more it will chase because he thinks you're a bad person (though we know you're not), so when you stopped and got down, he would stop too as he thinks that you're no more a threat. But not all dogs are like that. I think if you ever come across this same situation some day, just stop, and pray it doesn't harm you. You might wanna wear some protective gear on the most vulnerable part (not the private one, I mean) like the legs and hands, the two places which are prone to dog bites. Since you can't harm dogs, you've to protect yourself. Take care and happy biking.

Dogs can smell a stranger and so he starts chasing. If you are an intruder, you will be chased out.

I know some people used to carry cayenne pepper and throw it at the dogs, but I would think that would make them more angry! I usually either just stop if it looks like that will work (some dog breeds have a chasing instinct, so if you aren't moving they stop caring). But if it is a mean dog that isn't just chasing, I will just speed up and out run the dog (unless you've got a greyhound chasing you, this should work, I can speed up to over 25 miles per hour for short distances, even on hills when I absolutely have to). But I only do this if the dog seems as if it would actually bite if it could get me. Normally if you just stop, the dog loses interest.