Dig stoke, who else likes to play in the dirt???

[VTskibum]

Lots of mud bogs on my local to be fixed, unfortunately the several hundred NICA kids and coaches riding weekly regardless of conditions aren’t doing their part.

In more fun work, tuned up this jump on another trail system w a buddy today.



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[evdog]

Don't the NICA kids have to fulfil a quota of trail work each year? Fixing the damage they're doing might make them reconsider their ride decisions.

[VTskibum]

Yes they’re supposed to, but pretty much only do trimming. That’s helpful as well of course, but low value compared to trail damage itself.

They’re a bit of an easy target for frustration given the size of the groups. Several friends are coaches of various teams and tales of pretty useless labor and coach trail maintenance knowledge abound.


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[californiagrown]

Every so often i logon to trailforks and check up on a trail i built 100% myself starting in fall 2019 and ending in summer 2020 (pretty perfect timing with all the free time i suddenly had). Ive since moved away and havent been back in a couple years. Its an unsanctioned trail in a suburban neighborhood in an area with other social hiking trails, but this trail i made MTB and DH specific. I just saw a video posted of a couple dudes hooting and hollering their way down the trail hitting every jump and extra credit feature and railing the steep slalomy section. Pretty cool to see folks stoked on the trail and riding it the way i built it to be ridden, and cool to see that all the effort i put into drainage, and tread, and overbuilding berms and features has resulted in a lasting trail needing next to no maintenance that still flows super well.

[evdog]

^^^ Nice work!

I built a trail back in 2000 when I lived on Vancouver Island for a summer. Hadn't been back there since I moved to Socal 15 yrs ago but I stopped in last summer and rode it. It was a little overgrown and the bridge I'd built to cross a gap between rock outcrops had collapsed. But with a bypass someone blazed around it the trail was still riding well. Helps when the surface is primarily rock though : )

[panchosdad]

Don't the NICA kids have to fulfil a quota of trail work each year? Fixing the damage they're doing might make them reconsider their ride decisions.

My experiences with NICA kids is that they're about the best mannered and responsible trail users out there. Granted we don't have hundreds of them, but I think our coaches have done a great job of drilling good manners into them.

[VTskibum]

I will agree with that, they have been drilled in good manners. Lots of thank you and have a good rides.

The trail maintenance thing still irks me though, not on the kids, but the coaches. Even if they don’t know exactly what to do, arranging a trail boss who directs their labor is still pretty effective IMO.


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[LeeLau]

Big rock repositioning and some berm work

[LeeLau]

Berms and rock rolls

[WaistDeepGroomers]

Nice LL!

After living on pavement for two years in Boston for grad school, moved back to Maine, joined the board of the local NEMBA chapter, and have built up a nice volunteer crew. Very excited to turn our couple hundred feet of vert into masterful Squamish-style Rampage flow/jank epics

One thing I have not for the life of me been able to figure out is how to lay out a berm... have a decent idea when there's a ton of space and you can build a sweet perfect C, but we have lots of spots that need a tight < 90 degree berm put in and I really struggle at laying it out. Any tips from the wise dig nerds?

[jackstraw]

Come on WDG! That berm you put in at SHP is still there...and works!

[evdog]

Berms are tough. It probably needs to start later than you'd think, and go further past the end of the turn than you'd think. At least that's been my experience building them.

[toast2266]

Nice LL!

After living on pavement for two years in Boston for grad school, moved back to Maine, joined the board of the local NEMBA chapter, and have built up a nice volunteer crew. Very excited to turn our couple hundred feet of vert into masterful Squamish-style Rampage flow/jank epics

One thing I have not for the life of me been able to figure out is how to lay out a berm... have a decent idea when there's a ton of space and you can build a sweet perfect C, but we have lots of spots that need a tight < 90 degree berm put in and I really struggle at laying it out. Any tips from the wise dig nerds?

I think the biggest thing with berms is to check your work frequently. Take your best guess on where it needs to be and start piling. Dig out the inside and pile up the outside. Mind your drainage. And as soon as it's starting to take shape, walk well up the trail and see how it looks. Walk far enough that the berm is out of sight, and then walk down to it. Does it look about right? Or does it look like it's gonna be awkward? Adjust accordingly. Walk and check things several times throughout the build. After it's built, ride it a bunch and see where the tire tracks go. Are they missing one part of the berm and running high on another part? Again, adjust accordingly. Don't be afraid to re-do something if it's not right.

And for tight berms, make the face of it as steep as your dirt will allow. A low to medium speed berm on a 90° corner should ideally have a nearly vertical face for the top half of it, with a nicely curved transition to flat in the bottom half. Some soils won't hold that shape though.

[WaistDeepGroomers]

I think the biggest thing with berms is to check your work frequently. Take your best guess on where it needs to be and start piling. Dig out the inside and pile up the outside. Mind your drainage. And as soon as it's starting to take shape, walk well up the trail and see how it looks. Walk far enough that the berm is out of sight, and then walk down to it. Does it look about right? Or does it look like it's gonna be awkward? Adjust accordingly. Walk and check things several times throughout the build. After it's built, ride it a bunch and see where the tire tracks go. Are they missing one part of the berm and running high on another part? Again, adjust accordingly. Don't be afraid to re-do something if it's not right.

And for tight berms, make the face of it as steep as your dirt will allow. A low to medium speed berm on a 90° corner should ideally have a nearly vertical face for the top half of it, with a nicely curved transition to flat in the bottom half. Some soils won't hold that shape though.

Thanks Toast

Reading the Lee Likes Bikes advice on building pump track, I read that same advise (steep face for short berms). People are riding over the top of the berm (going outside of it) late in the corner, which makes me think they aren't getting pushed far enough towards the exit earlier in the turn. Will try and give it a re-work tonight! THanks

[toast2266]

Thanks Toast

Reading the Lee Likes Bikes advice on building pump track, I read that same advise (steep face for short berms). People are riding over the top of the berm (going outside of it) late in the corner, which makes me think they aren't getting pushed far enough towards the exit earlier in the turn. Will try and give it a re-work tonight! THanks

If people are going over the top late in the corner, it could a bunch of things:

- berm kinks creating a weird apex
- berm isn't long enough
- berm isn't tall enough
- berm isn't steep enough
- it's just a tough corner and work should be done to slow down the entrance speed.

[Clownshoe]

As stated above, If the radius of the berm is OK, and the speed going into the corner isn't too high, then a berm that people go over the top at the end can be because there isn't enough material at the end of the berm, and the berm finishes too early.
Depending on the shape of the ground where the berm is located, making a berm with lots of material at the end can make a "bathtub" where water collects. Trying to let the water drain out the end of the berm with outsloping can result in this "over the berm" ride line.

I know some singletrack builders may disagree with this, but I find a culvert can solve this problem. When you're roughing in the berm, keep the trail exiting the berm insloped and keep the berm going farther than you think. Embrace the bathtub. Then excavate for the culvert. Make sure the culvert is installed at the low point, which is why you want to rough in the shape of the berm before you dig for the culvert. Dig a sump on the uphill side of the culvert where sediment can collect. If the culvert is installed properly, with enough downhill slope through the culvert, it'll be self cleaning and won't clog up. If the culvert is "flat" it will fill with sediment and clog up. The culvert usually needs to be longer than you think. Digging enough for the culvert to be sloped downhill across the trail can be a pain in the ass (or impossible if there's bedrock).

Of course dragging culverts into the backcountry isn't always appropriate/permitted depending on where you're digging. This style also can also require more maintenance than a berm that ends in an outslope to let water drain out naturally, but I find it results in a much better riding trail in the end. For rouge builds I use a chunk of PVC or whatever I can scavenge. For proper builds use double walled rigid culverts.
Never use flexible singlewalled culverts (sometimes called Big O). Big O sucks. It gets crushed and flexes in the ground and fails relatively quickly.

[toast2266]

^^^ agreed. We have a lot of trails that were built years ago with no regard for drainage. Now those trails are getting a lot of use and need more work on berms / drainage, etc. Aside from a major reroute, sometimes a culvert is the only real option.

[californiagrown]

I think the biggest thing with berms is to check your work frequently. Take your best guess on where it needs to be and start piling. Dig out the inside and pile up the outside. Mind your drainage. And as soon as it's starting to take shape, walk well up the trail and see how it looks. Walk far enough that the berm is out of sight, and then walk down to it. Does it look about right? Or does it look like it's gonna be awkward? Adjust accordingly. Walk and check things several times throughout the build. After it's built, ride it a bunch and see where the tire tracks go. Are they missing one part of the berm and running high on another part? Again, adjust accordingly. Don't be afraid to re-do something if it's not right.

And for tight berms, make the face of it as steep as your dirt will allow. A low to medium speed berm on a 90° corner should ideally have a nearly vertical face for the top half of it, with a nicely curved transition to flat in the bottom half. Some soils won't hold that shape though.

Yep, constant checking of the berm layout by walking uphill out of sight and then pretending to ride down into it are key to get a feel for the trailspeed, and thus the needed radius/steepness of the berm. Always overbuild the shit out of berms as they will settle and erode to 2/3 the size within the first year. I personally find many/most berms end far too early for my liking so i tried to build my berms past the point it looks like they are needed. Its an iterative process to get the layout right so dont bother compacting until you are positive the arc works and you have more than enough dirt piled up. No one has ever said "ya know, that berm provides too much support and allows me to carry too much speed through it". Dig out the inner 5' of trail to get your dirt and pile it high. Bigger is better and a 5' wide trail during construction will end up being 2' wide after everything grows back in next spring.

If drainage is an issue, i tried to build the end of my turns going downhill, and then a quick wheelie hump back up to trail grade. This allows for the turn and berm to flow downhill, with a low point/drain on the downhill side for water to drain off, and if the berm is built right you can rail the berm and then pump/absorb the little hump afterwards.

halfassed berm suck and are a waste of time and effort. Great berms can be the funnest feature on any trail. Dont waste your own time and effort by halfassing.

[Clownshoe]

Always overbuild the shit out of berms as they will settle and erode to 2/3 the size within the first year.

Bigger is better and a 5' wide trail during construction will end up being 2' wide after everything grows back in next spring.

Yes and Yes! These are great points

[climberevan]

I personally find many/most berms end far too early for my liking
halfassed berm suck and are a waste of time and effort. .

On our big new marquee local trail (3000' climb over 15 miles), there are 2 sections with bermed switchbacks. Every. Single. One of them ends too early, so you must slow down below "trail speed" to make the turns. It's a professionally, mostly machine built trail, and I don't understand why they didn't just go the extra 10% to make it flow. The worst part is that there is a nice looking start and middle berm in each one, so you get suckered in, only to find that the berm just peters out 5 feet too soon.

[LeeLau]

All good advice on the berms. This advice is for a trail which was kept relatively narrow for a flow trail with lots of greenery to trailside and just my personal obs

- intent is to keep it "blue". I can almost ride it all uphill for example

- the berm is on a shallow angle part of the trail. In ski touring terms, the trail is climbable without heel lift risers and the berms are on the rest spots

- the entry into the berm is even slightly flat to slight uphill so riders don't have to brake hard into them. The exit is the same. It means I don't have to worry too much about braking bumps

- the berm was built with dirt with the big to medium rocks sifted out. Ie it was built with mostly fine dirt. When I maintain them and watch people riding them I see the majority ride the high to middle part of the berm. It's deliberately not built high so that's as it should be. Some ride low and that's usually beginner's and little kids who can't carry speed.

Rocks and bigger things like sticks and debris etc are dragged into the lower part of the berm which can be a hazard to beginners, lighter riders. The fine dirt from the high part of the berm also washes into the lower part. I rake or toss the bigger debris off the inner part of the berm. I then dig out the inner berm, rake to the higher berm, sift and repeat until the berm is restored. Then compact.If I've done it well this only needs to be done every couple of years.

The TLDr part

- routing is probably the most important
- not all berms are the same just like all trails are not the same
- do it well the first time and you can be lazy going forward

[LeeLau]

Edit by the way I learned a from Clownshoe and friends about routing berms and the entry exits being friendly from Earth Circus, which is masterful routing

[californiagrown]

Ill also add to not make the berm too close to trees on the inside. It fucking sucks for the taller riders to feel like you are going to smack your head if you try and lay the bike over and ride a berm/turn hard.

[Andeh]

One of my friends who builds a lot of our local trails loves to build berms. A couple things he's mentioned and I've noticed.

1) as others have said, it's almost impossible to make berms too steep, unless it's on a trail for beginners. This is compounded by how dirt settles/washes down from the peaks - after a year, they'll be a lot less steep than when they start.
2) he has learned the hard way (after having to start over on berms after over a year of fighting reoccurring bomb holes) is that good dirt is key. He makes a mine pit, and discards all the gravel and organics from the top few inches. Then he's started using a battery powered tiller to mix dirt from his mine pits, to help blend the silts, clays, and sands together uniformly. Our local soil tends to have lots of layers, so when he didn't do that, he'd end up with some parts that didn't have enough clay to hold it together.
3) he likes to dig a ~6" sump/drainage ditch on the lowest point (opposite from the berm), for water & leaves to collect, which extends past the exit. These are easy to clean out with a McLeod or small shovel periodically. When he can, he puts in a pipe crossover under the trail after the berm.
4) major personal gripe of mine on other trails in my region is people who put in a "berm" which is basically only at the entry, but don't do anything for the exit because they're concerned about water runoff. All that does is make the entrance to the corner ride much faster than the exit supports. If drainage is really that much of a problem, don't put in a freaking berm, just make the corners flat but bigger radius so they still ride well.

[toast2266]

4) major personal gripe of mine on other trails in my region is people who put in a "berm" which is basically only at the entry, but don't do anything for the exit because they're concerned about water runoff. All that does is make the entrance to the corner ride much faster than the exit supports. If drainage is really that much of a problem, don't put in a freaking berm, just make the corners flat but bigger radius so they still ride well.

A lot of trails struggle with this. People want to have the trail swing back slightly uphill to scrub speed and milk vert, but they also don't want to turn the berm into a bathtub.

Aside from a culvert like discussed above, I think the best solution is to build 2 berms. First berm does 80% of the turn, but ends pointing slightly downhill so it drains out the exit. ~10 feet later another berm finishes the last 20% of the turn to point slightly uphill. 2nd berm can drain out the entrance, and generally can be a lot smaller than the first berm. The key is to grade the 10' in between the berms so water can easily get away, otherwise you end up with a perpetual greasy spot in between the berms.