Challenge Double Problem

This one is very difficult, but with practice is doable. Try to ignore the other stuff until you get the first flip to manual down.

Focus on landing a back or front flip to manual, then ride for 10 meters. If you get to a point where you can do that more than failing, you're ready to push for the second flip and grabs. Below is the strategy I found easiest.

1. Flip on first hump with modified grab to manual
2. Flip off the right side of the second hump to maintain some speed, could modify grab here but I didn't. Going straight over the hump kills most of your speed and makes the second flip quite difficult, if you angle off of it you can get much more repeatable speed for flips to manual.
3. Maintain manual to the wood ramp, ollie to modified grab and land

I'm sure there are better ways to accomplish this but I found this method most repeatable.

Angling off the second ramp is what did it for me too. You don't need much air to pull off a sketchy back-flip.

Basically colonel is giving you the guide to how to get your momentum going mostly for the second flip. Not really the first flip is going to give you the most practice but maybe try the challenge without the actually trackers from the challenge and then give it a go.

From most of what I've seen, getting the second flip is really what people are trying to focus on. As colonel p mentioned going from the first flip to the manual is really the trick in itself. Glhf