How good is a bike for cardio?

[Equilibrium]

It's good but not as good as running, because i live in canadia i like to use it during the winter when there are 2 feets of snow outside. I could still run, but i ****ing hate snow.

[skyler]

I usually do about 7 miles on the exercise bike just to warm up.. but roadwork would be the best cant really replace it.