How do you get to mount coronet on Pokemon diamond?

You must have a bike and go to oreburgh city. Then you go up to see someone riding a bike. There is a ramp, get on your bike then ride it, to the ramp then press B. You will go up it. When your up, turn left, keep going straight until u see a cave, go inside it. Now you should be in mount coronet or you can go through route 206, which is bicycle road.