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  1. #1
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    Breaking the "Rules"

    I started this thread to get another thread back on track. We were discussing the IMBA guidelines for trailbuilding and how some people are of the opinion that these guidelines are "rules" and must be adhered to no matter what.

    Post up your examples of trails you have built that break the "rules" but still work. Constant maintenance doesn't count. The trail must be sustainable.

    Here's an example:

    One of the best known guidelines is "Don't line the path to Grandma's house." Logs along the side of the trail will stop water flow across the trail and cause erosion. Unless....

    The soil here is round loose gravel. It drains almost instantly even in Vancouver Island rain. The logs are to hold the partial bench in place (broken rule #2) and to keep people away from the edge. It's held up for over 5 years so far with no maintenance.
    Breaking the "Rules"-imba.jpg
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  2. #2
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    Page 1 of the IMBA books. These are Guidelines, not rules or standards. Specific adaptions can be required for your situation. I sure added that to the French version when we published it a couple years ago.

    I've worked in a coarse sand situation where a 6% was the maximum sustainable grade. Pretty far from the 10% IMBA suggest.

    In another place, crushed limestone is the main component of the soil to you can ride even after 2 weeks of rain with no issues at all. Even 300 racers on a rainy day leave no trace! Unfortunately, it also have a bad tendency to slice tires and dogs pawls...

    This is where experience get in line.
    A trailbuilder from the north

  3. #3
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    Odd you should mention the crushed limestone. Where I am now there is crushed limestone or clay. Sometimes on the same trail. The limestone never gets wet and the clay never dries out.

    I never had to deal with this clay before. It's slippery and really hard to shape when you dig.

    By the way. I was almost living in Pembroke. I ended up back in Southern Ontario for a while at least. Hamilton has the best cancer hospital.
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  4. #4
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    Finally
    This thread is going to need a sticky

  5. #5
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    Quote Originally Posted by faceplant72 View Post
    sticky
    Wet clay?
    A trailbuilder from the north

  6. #6
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    Quote Originally Posted by HypNoTic View Post
    Wet clay?
    Yeah, a little sticky.
    Breaking the "Rules"-mud.jpg
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  7. #7
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    Thanks for this thread Trail Ninja

    Wet Clay - my favourite (that's Canadian)

    Here's 2 spots on one trail that break a bunch of rules at face value, but...
    Breaking the "Rules"-46-third-creek-crossing-below-1.jpg

    Breaking the "Rules"-45-third-creek-crossing-1-1.jpg

    So we have half bench on a trail that was built with the outslope higher than the inslope although it no longer looks like that, a log on the outslope (there's also one above the trail embedded to act as a dam in the choke above the creek crossing that slows the heavy seasonal flows), 10% grade is hopeful and I don't remember the 50% rule being mentioned on this trail.

    Under the tread there is rock, lots and lots of rock. Water can drain through from above the trail or flow over the tread if the flow increases. Over time silt filled the tread and regardless of water on the "bridge", the trail remains solid.

    The half bench is an optical illusion - it's about 75% bench and the riding line is about 3/4 of the way from the edge of the full bench to the upslope. So it's really a full half bench with security and sight lines. No matter how you come off the creek crossing (which is a gentle G-out), you will not ride on half bench. After all, who really wants to clip their bars on the little tree mid-corner?


    Breaking the "Rules"-p1020566-1.jpg
    Yes this berm crosses the falline and exits uphill. It also starts by entering uphill.
    Breaking the "Rules"-p1020721-1.jpg

    It has seen at least a half dozen 200-400mm in 48 hour rain events. Under the tread in the lowest section is maybe 2 tonne of rock drainage. We have an absolute hatred for the idea you can build buried rock drains, but in this berm that is exactly what we built. It was a challenge and is an awesome berm, but due to the march of time the entrance has widened a little making the jump in so clutch that now everyone uses the cheat line. Given that after the last 2 massive rainfalls (50mm per hour) we have had to lift the paving stones in the base to clear silt, resulting in a bathtub-like drainage, we have decided that when we get time we will reshape this berm and make it even radder, starting at the entrance. The exit will still be uphill, but different. Rain is finally starting to fall after 2 months of none, so soon, Mr Berm you will taste shovel again.
    Attached Thumbnails Attached Thumbnails Breaking the "Rules"-p1020742-1.jpg  

    Last edited by Ridnparadise; 10-12-2012 at 05:48 AM.

  8. #8
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    Deleted - double post
    Last edited by Ridnparadise; 10-12-2012 at 05:52 AM.

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    There is one section here than is like 1/3 bench, and over 10% on a sandy hillside, what must I do to stop the errosion on on this trail? do I chip into the mountain for a full bench, or put rocks under the falling side and build up a platform?

  10. #10
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    Quote Originally Posted by Tulok View Post
    There is one section here than is like 1/3 bench, and over 10% on a sandy hillside, what must I do to stop the errosion on on this trail? do I chip into the mountain for a full bench, or put rocks under the falling side and build up a platform?
    Pics?
    Are you talking about solid rock? "chip into the mountain"

    Can you put in a rolling grade dip? It would hurry the water off the trail and give you a chance to bench in a little farther. If you have solid rock, usually building up would be your best option. Consider wood for building up in that case. I don't have any good pictures of ladder bridges incorporated into solid rock but I've seen it done with good results.
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  11. #11
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    Of course I don't have any "under construction" pictures. There's a wooden culvert under this corner with a french drain on the inside of the curve. It will eventually collapse but not for a good long time. It's split red cedar 8" thick & filled with rock.

    Breaking the "Rules"-malcolm_054-2-.jpg
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  12. #12
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    No comment required.

    Breaking the "Rules"-feb8073.jpg
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  13. #13
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    Quote Originally Posted by Trail Ninja View Post
    No comment required.

    Click image for larger version. 

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    Me likely! Straight roll in and roll out so someone with a half decent bunny hop wouldn't even touch the logs Depending on the size of the log and other variables I like to bury a largish rock about 4' in front of the log leaving 2-3" of the rock above ground for a bump to help the hop over the log, but the bump is still small enough that someone can still front tire--->back tire over the log too.

  14. #14
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    These trails were built for 10 to 14 year olds to learn to ride. I like your idea of a kicker. There's room to put one in just to the right of the stack. Gives the kids 3 options. The long log in the distance is now half-buried lengthwise as a "no consequence" 10 foot log ride.
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  15. #15
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    Here's an under construction, no consequences log on the outslope skinny leading to a line of outslope rocks continuing the skinny.

    http://forums.mtbr.com/attachment.ph...1&d=1350095175
    Attached Thumbnails Attached Thumbnails Breaking the "Rules"-p1050462-1.jpg  


  16. #16
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    Quote Originally Posted by Ridnparadise View Post
    Here's an under construction, no consequences log on the outslope skinny leading to a line of outslope rocks continuing the skinny.
    Slight consequence if you time it right. Just bruised knuckles.
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  17. #17
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    their log pile guide is a bit overkill. i'll try and get some pics of the one's i've made, they are holding up just fine, and are not tied/bolted/etc...

  18. #18
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    I think IMBA's rolling crown switchback is a poor design guideline. We've been over this one before.

    While it results in a very sound turn, the problem is that the amount of work required to make one is so enormous that it wastes time and effort that is always in short supply.

    Walt

  19. #19
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    Quote Originally Posted by Walt Dizzy View Post
    I think IMBA's rolling crown switchback is a poor design guideline. We've been over this one before.

    While it results in a very sound turn, the problem is that the amount of work required to make one is so enormous that it wastes time and effort that is always in short supply.

    Walt

    More often than not it will end up as an insloped berm over time anyway.

    Where ya been Walt? Long time.
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  20. #20
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    Quote Originally Posted by Trail Ninja View Post

    More often than not it will end up as an insloped berm over time anyway.

    Where ya been Walt? Long time.
    Note my sig.
    I saw the thread about your illness in Passion, and added my condolences. It's good to see you still posting, still stirring the pot, TN.

    Me? I'm waiting out a Dept. of Natural Resources review that is still stalled heading into Year 2. No new trail for me again next spring, probably.

    Walt

  21. #21
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    I'm not sure it's "against the rules" but I find sometimes that other xc trail workers don't see the value or power of sculpting things with packed dirt. (My background is bmx/DJ, so I know you can do a ton with dirt).

    There are people who I have worked with on work days who would have wanted to cut this root out.



    My solution was to pack dirt back where it used to be (on top of and below/above the root):



    I don't know whether this breaks the rules. But it does run up against the often-heard argument that dirt doesn't last "it'll just wash away again." Yes, it will. But it'll take a long time. Last time I covered up this root was 3 years ago.

    Added a step-up roller to a short climb.
    Before:

    After:

    After (view from other side). Note that the roller causes a diversion of runoff off of the path to the side. Some people say water bars on not favored by IMBA any more. I don't know?!


    Tree fell down. First we put branches around it to ride over it like that. Then later I went back and packed dirt on it. Left a little log showing at the top to keep the "log feature" feel slightly there, rather than just pure dirt roller.





    Just like with dirt jumps, if you dig and shape while the dirt is damp, then pack really well, it will dry and harden and become very solid. Wasn't even necessary to wire the logs together or anything like that. True, this feature will get worn. But, no big deal if I have to dump two wheelbarrows on it two years from now. I feel like some "by the book" people would make this more complicated than it is. Am I wrong?



    Here's another one. A heavily eroded spot known as the "root drop." Over the years, the tree roots have become more and more eroded.

    Some people have suggested "armoring" with rocks and crushed granite. I don't know exactly what they mean by that.... but to me, it seems like crushed granite especially "washes away" a lot more than packed native clay does. Packed clay is pretty strong.
    I would propose packing dirt back where it used to be. Once again, I don't mean just dumping dry dirt. I mean truly packing damp dirt, the same way as you would with solidly packed dirt jump.



    Of course, I'm open to listen and help the trail steward/ trail boss as he sees fit. One thing I HAVE learned is that nothing irritates a work crew leader more than volunteers who each have their own opinion and none have "read the book." So I try to keep my mouth shut, and/or prove things just by doing them.

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