十四.Building berms
Good berms are easy to ride, and they let you generate mega speed.
Radius. The tighter the turn, the harder it is to make, but the more pump it gives you.
Six- to 10-foot turns are the funnest overall, but a few 3-footers keep things interesting.
Tight: 3 feet - Experts only!
Medium: 6 feet - Good all around.
Wide: 10-12 feet - Fast!
Banking. When you rip a turn, your speed and the radius of the turn combine in a mathematical blender
to create the cornering Gs and your lean angle. For example, if you ride 15 mph through a 15-foot-radius turn,
you generate 1G and lean 45 degrees (the turning force and gravity
average each other out; see diagram).
Our goal is to always press the tires directly into the ground. This way,we don’t need traction between the tire and the dirt — it’s like we’re riding a roller coaster (as a matter of fact, roller coaster designers use the same equations).
Your berms should have smooth banks that transition gradually from flat to about 55-60 degees (the steeper,
the better — dirt is usually the limiting factor). The main worn line will be at 30-35 degrees;
this corresponds to a turn of 0.6Gs (a nice sports car).
A 60° top bank will let riders pull up to 2Gs without sliding; beyond that the bike will drift — but if you’re pulling
3G turns like a pro, you can handle it!
1. Mark your arc. Make a giant compass out of a stake and some string.Measure your radius,
plant the stake and mark your arc with paint, chalk,
etc. Your main riding line will end up on or near this mark.
2. Pile dirt around your arc.Start piling it about 2 feet outside your mark.
3. Keep piling until the dirt is at least 50% taller than the envisioned berm (you’ll be compacting the dirt).
Your outside berms will be three feet tall, so shoot for a pile 4.5 feet tall. Yeah, that’s a lot of dirt!
4. Working from the top down, slide the loose dirt down the face to get the shape you want.
It’s almost impossible to get a nice shape by adding dirt; it’s much easier to move dirt. Let gravity help you.
5. Pack as you go. Give it a little flat top. The riding surface should be rock hard and super smooth.
When you get the shape you want, water it and let it sit overnight.
A berm is a lot like a roller, only it’s really wide (and curved). Make your berm as tall and steep as possible in the middle, then let it taper toward the ends. There you will build rollers.
十五.Building rollers
These lumps of dirt are so sweet and versatile. You can roll over ‘em, pump ‘em,
manual ‘em or even jump ‘em. All rollers are fun to ride, but the best are:
Consistent. Make sets of equally tall, evenly spaced rollers.This lets you find a rhythm.
Not too tall or close. The most common mistake is building rollers too tall, too steep and too close together.
This feels OK at low speeds, but when you get going fast they’ll really ball you up.
1:10 ratio. If your rollers are one foot tall, they shoul dbe 10 feet apart.
This height:length ratio is relatively easy to ride,
yet it provides excellent pump and speed. You can make your rollers taller and closer.
Just know your track will be trickier to ride.
Width: Single lanes 2-3 feet. Interchanges 4-6 feet.
1. Build your berms first. Place the first rollers right at the ends of the berms, where the curves turn to the straight.
Space the other roller(s) evenly along the straight.
2. Pile dirt on the marks. Keep piling until the dirt is about 50% higher than the desired rollers.
If you want your roller to be six feet wide on the riding surface (top), make your pile about eight feet wide.
3. Working from the top, slide the dirt down to make smooth transitions. Remember: We’re talking about a sine wave here
4. As you get the shape you want, pack the dirt like crazy.Extend the top of the berm so it goes all the way to the roller.
Smooth and pack the sides of the rollers as well. Water your gems thoroughly and let them sit overnight.
When your roller abuts a berm, shape the slopes to they smoothly transition into each other.
Viewed from the side, the roller would still be a perfect roller; there just happens to be a berm on one side of it.
十六.Building interchanges
Crossover lines add options and fun galore, and they let you turn in more than one direction.This ain’t Nascar!
Interchanges from outside berms to crossovers
1. Finish the berms on the ends of the straights.
2. Mark the inside berm. Mark the rollers for the entire straight. Your interchange berms will be next to rollers.
You will build these berms and rollers together.
3. Begin to pile and shape the interchange berm and roller.
The interchange berm and roller should flow smoothly from the outside berm.
The front of the roller is part of the outside berm, which is part of the transition berm,
which is the front of the roller … It’s a complex 3D shape!
4. Do the final shaping, packing and watering. Finish the other roller on the straight. Water, wait a day then ride!
5. Finish the other rollers on the straight.
十七.Interchanges from side straights to crossovers
1. Finish the outside berms on the ends of the straights, as well as interchanges from the outside berms.
2. Mark the inside berm. Your rollers should already be marked. Your interchange berms will be near rollers.You will build these berms and rollers together.
3. Begin to pile and shape the interchange berm and roller. The berm will “point” into the straight, like a freeway off-ramp.
4. Do the final shaping, packing and watering.
十八.Build in this order
1. Grading, drainage and sprinklers
2. Outside berms
3. Outside straights, including rollers and interchanges
4. Inside berms
5. Inside straights, rollers and interchanges
6. Bandstands, concessions, media center
十九.Good shovel technique …… saves time and energy.
1. Holding the shovel high on its handle, place the point where you like.
2. Jump high onto the shovel, driving it deep into the ground.
3. Standing on the shovel, wiggle the handle until the blade is fully embedded.
4. Lean back to dislodge a big, juicy clump of earth.
5. Grip closer to the blade and place your treasure where you like.Repeat a zillion times.
You can easily maintain a good aerobic heart rate–I know‘cause I’ve worn my monitor!
二十.Riding your track
Pumping is simple: Just absorb any surface that faces the way you’re coming from,
and push into any surface that faces the way you want to go. Part of this push gets translated into forward motion and,
voila, you gain speed. You can pump any bump: rocks, logs, water bars or curbs.A pump track is a laboratory for non-pedal propulsion: A loop of rollers and berms that can be ripped around without turning the cranks.
You start by working the rollers. Light, heavy, pull, push. You hit a corner hard and gain speed.
The next set of rollers approaches fast. Too fast to roll – better manual. Pump another berm and you’ve reached 20 mph.
Too fast to manual – better jump. You might hit a dozen rollers and four berms in less than 10 seconds.
The workout is total, the speed is real and the possibilities are endless. Here are some basic tips to get you started.
二十一.It’s all about position
Everything fun on a bike starts with the neutral attack position:
Centered fore-aft. Weight balanced completely on your feet. Hands weightless.
Centered up-down. Hips halfway between standing and hitting your seat.
Back flat. Torso level.
Head up. Look at the next turn. Yes, all the way out there.
Elbows out. It’s solid, and it helps you whip your bike around.
This is the A-1 key to all riding. Practice until it becomes automatic.
Pump rollers
You’re a bouncing sine wave. The rollers are one sine wave, and you are another. As you ride,
bounce up and down (with your feet) so you’re light on the front of the bump and very heavy on back of the bump.
You basically take the wave of your energy and shift it just a bit ahead of the bump wave.
Don’t touch the fronts. Loft your front wheel over every frontside, and push HARD down every backside.
This is a lot of work, but it builds so much speed you’ll freak out the first time you succeed.
You are a floating head. Try to keep your head and torso flowing in a level line.
Use your arms and legs to pull and push as you go. You are a killer death lizard from Pump Island.
The lower the better. At the top of each roller, the lower you are on your bike (or the higher the bike is – trip out on that)
the more range of motion you have for the pump.
Use them legs. Compress on the tops. Extend in the troughs.Let your arms go along for the ride.
Remember your attack position!
Rip berms
Look through the exit of the turn. Yes — this is so key!
Lean your bike. It’s the only way to make a turn.
Trust the berm. As long as your tires are pressing directly into the ground,
you can do (almost) no wrong.
A berm is a hole turned on its side. Enter low. Extend and press into the first part.
Absorb the “front side” on the way out.
Ready for the roller. There should be a roller right at the exit.
You’ve unweighted to leave the berm — use that lightness to get over the roller!
Then pump the heck out of it.
Remember your attack position!
It’s a fresh start
Pump tracking totally applies to “real” mountain biking, but it’s so unique it’s almost a completely
different sport. And this can be a good thing.
As we ride over the years, many of us develop bad habits. We learn these habits because they seem to serve us.
We stiffen up when we reach bumps, so we can protect ourselves. We keep our bikes upright in corners,
so we don’t fall over. These habits actually detract from our riding, but every time you hit a bump stiff and survive,
or take a turn upright and stay on two wheels, that counts as a success.Not as a riding success, but as a survival success.
So our brains say “Sweet, that totally worked!” and the habits become more and more ingrained.
The only way to erase those etchings is to practice – no,exaggerate – proper technique.Staying loose in bumps,
leaning your bike in turns: that sort of stuff.
A pump track is a laboratory. It’s non-threatening,
and it’s so different from normal riding that it allows you to ride your bike with an entirely new mindset.
If you’ve suffered too much stress over the years on your XC bike, ride your pump track on a different bike.
Use flat pedals. Wear a t-shirt and baggy shorts. Leave your heart rate monitor in your shrine.
Play.
Exaggerate. Pick a key technique and beat it to death. Ride with open fingers.
Try to look two turns ahead. Completely straighten your inside arm.
Experiment. Try different positions and lines. Push here, pull there. If it works
you’ll accelerate immediately. If not, well,try something else.
Be cool. If you fall into any old self-hating behaviors, STOP! Chill out. Come back with a sense of play.
Pump tracking is fun for its own sake, but if you take advantage of this opportunity it’ll improve all of your riding.
Enjoy the process
As you get faster through the rollers, you’ll progress from pumping them to manualing them and finally to jumping them.
Super fun.Pump tracks: I can’t think of a better way to improve your riding and have a great time.
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