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  1. #1
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    Berms, Jumps, Pump track, wooden starting ramps etc... For DH bikes?

    Hi All, I've spent the last week or so turning through the epic threads on here about Pump tracks, Jump trails, etc...

    I am gearing up to build a small trail at my house in Kent WA. We have a slight grade , which then flattens out. (I'll get dimensions, and pics once its light out)

    Would like to do 2 trails and a pump track in the long run. I am currently getting Fill dirt brought in, and have a lead on a mini excavator. Going to start with the "beginner" trail

    NOW, Questions!!! How do berms, jumps, and pumping/doubling rollers change for Long travel bikes? (6-10" travel) we may get a dirt jumper or two, but not likely.

    Does the 8' berm rule still apply or does this need to be made bigger? We need a pair of berms at the top to try and build speed, and direct the trail, we put them in with shovel and wheel barrow, But they just feel wrong... It may also be the shaping/spacing of them?

    The other feature types we have yet to try, But would like to know if the rules of thumb change at all for the longer travel bikes.

    And lastly! IF we are unable to build enough speed with the grade+ berms. There is the option of putting in wooden starting ramp. However I am having a hard time finding Good info on this. Was thinking 4x4 uprights on top of anchor blocks, 2x4 cross members, and surface. 8' wide so you can get 2 bike on it, and run up the ramp instead of stairs. paint+sand for grip and weather proofing.

    Not sure on angle? 45*? less? also 7' up seemed like a good height? To big and it gets $$$ and starts running into the first berm.

    Thanks all!

    -Levi

  2. #2
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    If you're mostly going to ride a DH bike on the jumps, make them less lippy and gaps a little bigger. You're going to have a hard time using berm-pumping or other momentum techniques to build speed on that type of bike (and it's also hard to pedal them up to speed) so I'd do an elevated ramp of some kind. Without knowing how fast/big you want to go or how much space/slope you have to work with it's impossible to say more than that.

    Honestly, if you want to dirt jump and ride a pump track, build for DJ bikes. If you don't have a DJ bike, get one. They're dirt cheap and they're more fun for that style of riding anyway. Who wants to ride a pump track designed for an 8" travel DH sled? Ugh.

    -Walt
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.blogspot.com

  3. #3
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    If you do the start ramp, here's a picture of a start ramp we built. Unfortunately, you cannot see under it. We use 4 X 4 treated posts and 2 X 6 treat for the sills and stringers. Decking is also 2 X 6, though the cross braces are 2 X 4. This one is eight feet wide.

    Berms, Jumps, Pump track, wooden starting ramps etc... For DH bikes?-start-ramp-resized.jpg

    This picture better shows the framing. The sills attach to the posts, and the stringers sit on the sills and attach to the posts, too. As you can see, this is a drop, but the framework is the same.

    Berms, Jumps, Pump track, wooden starting ramps etc... For DH bikes?-drop-anatomy.jpg

    Good luck with the rest of it.

    D

  4. #4
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    dburatti: Thanks for the Pics! Very very Helpful!

    Would you know about what angle that start ramp is? And for the decking is it pressure treated? or?

    Walt: Our friends and Us really only have Long travel bikes. many only this last year. So for the next 2-3 years its really only going to see DH bikes. One person also has a DJ bike, that he may bring out. Considering This whole project cost less then what a nice used DJ bike costs... it would be a hard sell for the 8 main riders. I will admit we have WAY more bike then we need. But most these guys came from dirt bikes.

    We wont be riding these trails at DH race pace, just practicing for when we dont have the time to make it to the real trails, or they suck due to weather. Pumping a Hard tail aint the same as the sled either!


    The area to work with is a L shape going to the left. its 50 feet wide and the straits are about 150-200feet long. id say its about 2-3% grade for the first part, then flat after the Bend.


    Pics!

    the top, where a starting ramp would go,(tree would get trimmed)


    This brush is hiding an old shed/concrete slab, no go for now (hence the starting berms)

    The lower left is where the land section turns left, the trees where it flattens. fence is about 50' back


    Most likely area for small pump track, more dirt is being brought in. Trails can go behind the bush and through the trees


    And the 50-70' behind these trees is all fair game.

    these pictures are taken from the top, and go down and to the left.

    Thanks all!

  5. #5
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    Quote Originally Posted by saber63 View Post
    dburatti: Thanks for the Pics! Very very Helpful!

    Would you know about what angle that start ramp is? And for the decking is it pressure treated? or?
    We set the ramp angle to match the angle of the dirt, which was also a start ramp that was not quite tall enough. If you really need to know, I can go measure it with a digital level.

    The decking is treated pine with a retention level of .35, which s suitable for ground contact. I use this for all my wooden features for framing and in some cases decking. For most of my decking, I switched to rough cut red cedar, which, even though it's costlier, I prefer. It has a better texture, smell, look, and will last almost as long. Plus, it's softer to cut.

    I primarily use a Paslode nailer with 3" galvanized nails, though occasionally I use screws. I rework or remove & replace features every five to seven years, which is not enough time for the wood to rot or the nails to pull out or rust out.

    D

    When you use lumber, make sure the cup of the board is facing down or facing another piece of lumber.

  6. #6
    i'm schralping yer thread
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    Just head over to Duthie and check out some of the construction techniques. There's start platforms on a variety of terrain/grades, including Ryan's, Paramount, and Semper Dirticus. Most of the lines were built by different crews so you'll have a chance to compare-and-contrast approaches.

  7. #7
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    Quote Originally Posted by dburatti View Post
    We set the ramp angle to match the angle of the dirt, which was also a start ramp that was not quite tall enough. If you really need to know, I can go measure it with a digital level.
    .....
    When you use lumber, make sure the cup of the board is facing down or facing another piece of lumber.
    Thaks for all the info! Im going to look around to see what i can get for what price, and go from there! Ill be hitting some trails this weekend, so ill just be sure to bring some measuring devices.

    Now im just worried the berms we started to put in are to small if we have a good sized start ramp...

    Quote Originally Posted by GeePhroh View Post
    Just head over to Duthie and check out some of the construction techniques. There's start platforms on a variety of terrain/grades, including Ryan's, Paramount, and Semper Dirticus. Most of the lines were built by different crews so you'll have a chance to compare-and-contrast approaches.
    Ive been checking out most of whats out there, alot of the start ramps are log built... wasnt sure if that made a hudge difference. I also get pretty wound up riding, and forget to stop and take pics/measurements

  8. #8
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    The best way to learn how to build this stuff is to go work with some experienced builders. Only way you'll get the knowledge and if you've just been riding for the last year you can meet some new people to ride with too and your sphere will grow.

  9. #9
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    I have a "epic" thread about roll-ins (starting ramps) over on ridemonkey:

    Roll-ins

    Several things affect the speed you can get from a roll-in.
    1) Height
    2) Steepness
    3) Transition or not
    4) Whether you can get a rolling start at the top, or if you're rolling in from a standstill.

    For the "standard" bmx bikepark box jump that is 5'-ish tall and 10'-ish gap, the roll-in is typically around 10' or 12' tall. 8' is okay, if it's vert quarter pipe, but 8' is not tall enough when it's a 45-ish degree flat-slant.

    I took this pic at the Whistler Air Dome:



    I have some video of it at 0:50 in this edit:
    Duthie Hill, WA, and Whistler Bike Park, BC, edit - cmc on Vimeo

  10. #10
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    Quote Originally Posted by specialev View Post
    The best way to learn how to build this stuff is to go work with some experienced builders. Only way you'll get the knowledge and if you've just been riding for the last year you can meet some new people to ride with too and your sphere will grow.
    I've been meaning to make it out to more work parties, The wife and i work odd schedules, which makes it almost impossible, and the one we did make it to, we got to clean out drainage ditches (important, but not helpful for out own trail )

    Quote Originally Posted by cmc4130 View Post
    I have a "epic" thread about roll-ins (starting ramps) over on ridemonkey:

    Roll-ins

    ........

    I have some video of it at 0:50 in this edit:
    Duthie Hill, WA, and Whistler Bike Park, BC, edit - cmc on Vimeo
    How did i miss that one!? I have most your other "epic" threads book marked! Thanks for the heads up and info! after digging through it, I'm definitely going to put in a start ramp. And probably going to go as big as I can get away with....

    Saddly the Excavator fell through, So i will most likely be renting a skid steer, It should move dirt faster anyways.

    As a heads up, These are our current go to trails (not my videos) Duthie Hill Voodoo Child and Gravy Train on Vimeo However for our trails everything will need to be rollable.
    https://www.youtube.com/watch?v=jVWVm4qJ3fo We're not that fast on DH bikes :P

    Our first trail would mimic these in terms of size,speed, and tech. However the future trail (or two) would be bigger.

    Still not sure on a simple pump track...

    Thanks guys!

  11. #11
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    I think it's fair to say that DH bikes always work better on a downgradient. The guys who have brought DH bikes to our pump/jump track (wcpt random edit - spring 2010 on Vimeo ) always end up coming back with a hardtail.
    That said, with the appropriate roll-in you could have a line/loop that is DH-bike friendly. Most of your pump comes from your feet and the rear triangle of your bike. That's why the mushiness of rear suspension makes pump tracks not fun (even on All-Mountain full sus). The only time I feel like rear suspension works okay on a pump track is with my Transition Double. Short travel and high psi. Lots of DH flow trails have pump features, but, once again, you have that decline working with you.

  12. #12
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    Quote Originally Posted by cmc4130 View Post
    I think it's fair to say that DH bikes always work better on a downgradient. The guys who have brought DH bikes to our pump/jump track (wcpt random edit - spring 2010 on Vimeo ) always end up coming back with a hardtail.
    That said, with the appropriate roll-in you could have a line/loop that is DH-bike friendly. Most of your pump comes from your feet and the rear triangle of your bike. That's why the mushiness of rear suspension makes pump tracks not fun (even on All-Mountain full sus). The only time I feel like rear suspension works okay on a pump track is with my Transition Double. Short travel and high psi. Lots of DH flow trails have pump features, but, once again, you have that decline working with you.
    We will have the drop in ramp, two berms, and the first jump, all uphill of the pump track... so entry speed shouldn't be an issue.

    Speaking of... with a 8-10' 45* drop in on a DH bike, whats would a good berm radius and height be? We have a 8' one put in to practice building, but it seems WAY to small for a drop in ramp... hell feels about right with about 3-4 cranks in... its only about 1' high right now though... would the 8' radius berm work if we make it taller? Or should we go up to 9 or 10? I'm not yet keen on judging speed -> feature size....

    where was I? Oh yeah! If we have a nice roll into the pump track, For a DH bike, there shouldn't need to be any changes on berm size , roller height, or spacing when compared to a pump track meant for 26" DJ/slopestyle bikes right?

    And I think the last(hopefully easy) question... I have a picture! What should X and Y be? or their ranges? (its supposed to be a left-right berm 8' radi, 3ft wide trail)


    Thanks again!

    -Levi

  13. #13
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    On the land you've described, you will not be able to build flow trails that will work well with a DH bike - not enough gradient, not enough space, etc. I mean, you can do it and fit in a few jumps, but I think you will regret it in the long run. You have what, 200' total? Or a little less? You'll spend 50 of those feet just getting up to speed, you need a runout at the end, and if you're on DH bikes you can only make the jumps so close together before you'll have problems, so you're really limiting yourself.

    I would seriously think about getting a few BMX bikes (if you're coming from DH/MX, go with 24"/cruiser) and starting with your pump track. It'll require less earth moving and let you experiment/screw up and figure out a bit more about what you like in terms of berms/radius/layout/etc. Bringing in heavy equipment before you've figured out how you want to build by *actually building* stuff is a bad idea - you'll just move a lot of dirt to the wrong places and have to redo it.

    BMX is cheap, it's AWESOME training for DH, and you can fit way more terrain into limited land for bikes with smaller wheels and wheelbases (and no suspension). Have you actually ridden your DH bike in a pumptrack? I have (I've ridden a CX bike in one too!) - it's awful, there's a reason you don't see anyone doing that.

    But it sounds like that's not what you want to do, so I'll be psyched to see what you come up with and I hope you prove me wrong!

    -Walt
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.blogspot.com

  14. #14
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    Walt,

    I hope to prove you wrong. But I'm not holding my breath! I'll admit what I want is borderline stupid/pointless!
    But I'll call victory if by the start of next season, I have a 2 trails and a pump track that we can ride on a DH bike.

  15. #15
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    You should sign up for this free trailbuilding school: Evergreen MTB Calendar

    Might not specifically speak to DH and pump track construction but I can guarantee that it is applicable. Some of the attendants are active builders/riders near you too.

  16. #16
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    any updates?!

  17. #17
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    Yes!
    I wont be able to get pics up for a bit (technical issues)

    We have been building the starting structure. Its 10' high 8' square with a 45* ramp. And a 8' radius dirt transtion.

    Still need to deck the ramp. And move more dirt for the transtion. Being 8' wide it takes aaalllooottt of dirt.

    Also the cost of rental machines is prohibitive. I can purchase a used machine, sell it a year later. For the price of a one month rental....

    We also cut out the last of the limbs and blow down on the proposed trails.

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