Mashup: Nico Vink and Friends' Season of Shred in Bikepark Châtel - Video

 From an erosion control standpoint, they should at least stabilize the side slopes of the trail. It would also look more aesthetic than too with something growing.

 It's not like they built this in the middle of a protected forest. It's a lift-access bike park.
Have you ever seen a ski resort? There's big clearing for their runs. This isn't much different.

 It doesn't look like erosion is happening down slope as a result of this trail. It looks like they built in drainage, and culverts etc... The sides of the berms do look unfinished, but with the material they're constructed out of, that's not going to be the primary source of sediment - it'll be eroded from the track when water collects and then is channelized by the trail

 @stylishskier: Yea my comment is more for preserving your investment standpoint and stabilizing the trail itself so it doesn't erode away.

 @stylishskier: As a certified master trail builder, this is a beautiful execution of terrain. While I agree, the giant mounds of dirt do make for an unfinished look, the angle of Repose, (The maximum angle the hill side can reach before stuff wont grow back) does not appear to be exceeded anywhere so revegitation is happening on the lower edges and spreading up and will probably complete the hill side next spring. vegetation is thin on the whole slop anyways meaning its probably very rocky soil. Rocks are stabilizers. As for the drainage issue I wouldn't have designed a basin that big to be drained by culvert but its definitely inside of acceptable standards. Given time, as long as those culverts done clog and/or get flooded out, this should weather into a solid trail and look likes its always been there in another year or so.

 @DragontalesDH: Sorry mate but angle of repose is nothing to do with the angle stuff wont grow at, but stuff growing in it will alter the angle of repose. Angle of repose is materials natural rill angle, where material considering nature, weather, pore spacing, moisture, geology, seismic and geochemistry naturally sit at. Adding vegetation further binds the material and steepens angle of repose, unless any of those forces mentioned above are greater than these frictional and binding forced of root and organic binding forces. The maximum angle that stuff wont grow at and the natural rill angle of material are significantly different.

 @DragontalesDH: plus it was only built this year !

 @gonzoracing: your not wrong. However it is used normally in trail building to refer to a good angle for the back slope of the bench cut. Basically so "the angle it needs to be at for stuff it grow back" because by definition, Too steep, and stuff won't grow. Everything gets eroded off.

Your not wrong strictly speaking. But in regular jargon things get burred

 I can see no responses from any French dudes especially, you see it in their infrastructure everywhere (not just MTB tracks) they really "just do" and don't care too much. They have years of winter resort building experience and what I see every year I go to France their MTB trail building is doing just fine.

 @DragontalesDH: Yeap know im not wrong. But this is, saying the angle of repose is ""the angle it needs to be at for stuff it grow back" because by definition, Too steep, and stuff won't grow. Everything gets eroded off.""

If you set up the angle of repose to equal your definition, and its above the angle of repose as defined by any global definition adopted throughout geosciences and engineering, screw what will grow, the material wont stand up. And here in lies the problem and complaints about maintenance, viability and sustainability, erosion et al.

I think "regular jargon" needs to reflect earth sciences and engineering standards or you are doing the (very small) trail building industry a huge dis service, and wont stand up to any scrutiny when present to and engage with larger audience.

 @gonzoracing: not sure what your on about. I think we are saying the same thing just in a different way.

My only point was that if you force a pile of soil into a shape that exceeds that natural angle of repose stuff won't grow. When doing back slope of a bench cut or the back fill of a berm (as in this case) if you keep that angle inside of repose (as it appears they did) stuff will grow back over time "completing" the look of the trail.

We are saying the same thing. Don't get ye panties in a bunch.