# Pump Track Help



## TitanofChaos (Jun 13, 2011)

Working on a backyard pump track and I need some info

if I have a 30' section from where a berm meets the level ground to another berm

is it better to put a roller right on the end of the berm (the roller peaks right at the end of the berm and is sort of built into it)

Or

am I best off rolling out of the berm and then up the roller?

excuse the crude diagram, I'll post pics of what I've got and a diagram with measurements later tonight


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## cmc4130 (Jan 30, 2008)

When you blend rollers into the entrance and exit of a berm, one effect is that the rider enters 'high' over the roller then takes a low line around the berm, then exits high again. The high-low-high body motion is similar to the other pumping on the track.

If you put more space between the entry/exit rollers and the berm, the person will be more likely to be UP over the roller, then low, then UP again higher around the berm, then low on exiting the berm. You really can do it either way. But with the second version, you would need a taller berm.

Here's a classic low-high-low clamshell style berm:









Whereas something like this is clearly going to send the rider low around the berm. 









This looks like it may be a ribbon style berm, where the face twists and the apex is super steep, forcing the rider to drop-shoulder....









Another ribbon style:









Here, the roller is set back a little from the berm. The riding line appears to be around the center of the berm (not carving up or down)....









Dig dug. My winter dig thread.

Exiting a berm high....









Monster wave style....









https://www.bikemojo.com/speak/showthread.php?t=75951


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## TitanofChaos (Jun 13, 2011)

Changing topic a bit here, I have pretty limited space but I'm sure I can make something work out here

based on the above pictures my assumption is it's best to put my rollers on the ends of the berms as I don't have space to build really tall berms

So here's the dimensions of the available space and a few potential track layouts, what's the best for the small space available?

the "X" in the first track is definitely a PITA as it interferes with roller spacing


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## cmc4130 (Jan 30, 2008)

I'm wondering about the 4' radius 180 berm. Are you measuring 4' to the riding line? Seems like it could be too tight. Could you do 6' ?









Lee Likes Bikes

check out this for a tight 180:








Big Guy Little Curved Wallride « Sunday Bikes « BMX Bikes and Parts










may not be what you're into, but if it were my yard, i would consider building a quarter pipe to turn around on in that section above the garage.










it wouldn't necessarily have to go up to vert. it could flatten out, like a transition to bank in this pic (yours truly). 
put a platform on it, and that could be your roll-in as well.... in order to pump a lot of speed out of it, though, you'd have to make it tall. 4 foot tall wouldn't cut it. it would have to be 8 at least, 10 even better.










this kind of extension out of a quarter transition creates a lot of speed...









another alternative would be building a wood curved wallride above the dirt part of your berm. 









wood transitions - Page 4


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## TitanofChaos (Jun 13, 2011)

the inside line is around 4', the space is 14' wide

I don't want dirt actually piled against my fence or garage so I lose about 1' each side there, then there's about 2' of width each side for the dirt pile

I think the riding line is actually closer to the 6'

still very tight for the amount of strait section I have to pump up enough speed


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## cmc4130 (Jan 30, 2008)

TitanofChaos said:


> the inside line is around 4', the space is 14' wide
> 
> I don't want dirt actually piled against my fence or garage so I lose about 1' each side there, then there's about 2' of width each side for the dirt pile
> 
> ...


maybe you could build that berm out of wood. it'll help it stay more vertical--you'll need to get sideways to pin a tight 180 berm.

this pic isn't really the dimensions we're talking about, but at least it shows a short/steep-faced wood berm....









if you're a good carpenter, build a bowl corner style transitioned face berm like this and you will be flying....


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## TitanofChaos (Jun 13, 2011)

I keep looking at this track, it's really close to the dimensions and shape I have to work with









I can't believe the rollers spaced 90" apart are really 2' tall....

check the video here leelikesbikes.com - The toughest 150 feet in mountain biking


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## cmc4130 (Jan 30, 2008)

TitanofChaos said:


> I keep looking at this track, it's really close to the dimensions and shape I have to work with
> ...
> 
> I can't believe the rollers spaced 90" apart are really 2' tall....
> ...


i think the videos kinda show that the track is rideable but not necessarily roasting-fun.... it's possible that with tweaks (like super steep-faced transitioned berms and mellowing out some roller heights, you could increase the speed. (and maybe they already did. that pic i posted above might be from the same spot.

zack dank had some great pics posted of a backyard setup:
Bike check/Farm check/mini mulch check/Backyard Track check

Note the tallness/transition/steepness on the berm behind this guy:


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## cglasford (Sep 26, 2011)

4' and even 6' is super tight for a radius IMO... I would love to see pictures.. that will be some serious sideways action to rip that on a 26inch bike!


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## cmc4130 (Jan 30, 2008)

TitanofChaos said:


> Working on a backyard pump track and I need some info


. . . . get started yet ? post up pics !


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## TitanofChaos (Jun 13, 2011)

everything is dug in, shaped and spaced out where I want it, now I have a ton of clay to move, 1 pickup truck at a time, but hey, it's free


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