I was returning back from some trail riding, riding down a very steep downhill on road. My speed was about 65-70 km/h, and suddenly I saw this man with his unleashed huge dog. The dog heard the rolling tires, and took off running towards me barking. I tried to slow down, and change direction to avoid a crash, but the dog was still running towards me. It was going to be a head to head crash, if I didn't manage to go around him in the last moment. After that he started chasing me like crazy. Then I started sprinting down the hill, and finally he gave up.

I'm not sure about what to do if this happens again. The dog was totally out of control. May be I could have stopped, but I hesitated, and I got a little scared actually. Not only because of the dog, but also the fear of crashing at that speed.

So, what would be the best action? Try to stop, get off the bike, and act like a human being (if you can before the dog catches you), or pedal as fast as possible?

I'd see if you can find out where the man lives. Call the cops. Tell them his dog attacked you.

Dogs seem to like jumping in front of a moving bike. Nothing you can do except stop. I've read in a magazine that once stopped you are supposed to put your bike between you and the dog. If the dog persists take a swig from your hydration pack and spit it at the dog. (I've never tried this so I don't know if it works) You can also get some dog repellant pepper spray from an outdoors store.

If it's down hill, I'd shift up and set a new speed record for the day

Flat ground, see how long you can spin your highest gear at 90rpm before you or the dog dies of exhaustion, lol

up hill? stop and put the bike between you and the dog and hope for the best.

start barking