[Kornphlake]

I'm in the process of building a dirt jump, slalom kind of trail in my yard. We have a couple of acres on a hill side with probablly 100' or more elevation gain. I'm trying to make the trail wind down the hillside in a serpentine fashion with bermed corners and sets of jumps in between. My problem (aside from being out of shape for digging) is that I can't seem to get the right radius on the berms so that I can really rail them, I'm either making them so tight that I have to brake hard and loose speed anyway or they're so wide that I don't really ride up the berm much at all. Is there some guideline as to how big the raduis of a berm should be with respect to wheelbase of the bike or something?

 

[firetoole]

I would suggest trying to start tight but don't pack it down yet just get like 4 or 5 guys to reide it out slowly. this will give you a more flowing effect, after you get the curve you want pack it down. then you got yourself a berm

 

[TheMontashu]

My friends always say if its sharper make the berm steeper

 

[Kornphlake]

maybe this is in the wrong forum? C'mon somebody has to have some tips on building berms, how do you know what size turn to start with, is it as simple as ride the corner at the speed you'd like and then make it a little tighter?

 

[Zark]

One thing I'd do is get an asphalt rake, like the CalTrans guys use to level asphalt, it is by far the best shaping tool for berms known to man. Another tool is a good tamper (see photo)

As far as design and construction is a hit and miss thing of reshaping until it has the desired outcome. I will say build the berm bigger than you'll think you'll need, it only takes one or two misplaced tires to tear the top off a small berm, where as a monster berm will only have a small divot.

 

[NotRyanMorgan]

look at pics of the sea otter slalom berms then do your best to duplicate
but seriously, id burn in the grass just by ripping the turn then build up dirt so you can carry more speed.

Morgan

 

[Bicyclist]

Sweet Firestone pics! That was an awesome section.