What burns more calories a brisk walk or bike ride?

When it comes to burning calories, your heart rate is much more important than what it is that you are doing. If you can reach and sustain the same heart rate for the same amount of time you will burn pretty much the same amount of calories regardless of activity.

For the same length of time, riding flat out will burn more calories than a casual walk, while walking briskly can burn more than a casual ride.

When you have a set distance, cycling will burn less calories than walking at the same level of effort, as the higher speed of the bike means you'll finish the distance faster.