Here's how I completed the hardcore challenges on the first level in proquest: Do the cheat to unlock all the bikes.Select the secret bike with any rider.
Then wait until the time gets to 1:58 and then start pedalling towards the train.Use the ramp to jump over the low part to do one challenge.
Keep on riding on the other side of the train [following the dirt track]until you come to a ramp.Jump on it without doing a trick.There is a pad which sends you back overthe train.
Grind on the telephone wire to complete another challenge.Next ride towards the house and turn left.There is a ramp there so you can jump onto the house to complete another challenge.
When you are on the roof jump on to the power lines on the right and grind for 60 metres balancing by using left and right to complete the hardcore challenges.
Added by: Izo "The King" M.. , ID#1246