How do you bootstrap a mountain bike dual slalom event?

I asked this question the first time I wanted to build a poor mans’s version of a dual slalom course.

But instead of going through the ins-and-outs of professional dual slalom course design like did in 7 Secrets of Dual Slalom Course Design, I want to focus on how you would plan a real dual slalom event.

Now I’m not a big fan of creating new trails just to fit a design, but rather enjoy using the existing terrain to my advantage.

If I can achieve the same goal without having to spend several weeks using a backhoe and a team of shovelers, then I will.

The point is to build a dual slalom race by spending as little as possible.

To do that, we need to apply the principle of “if it ain’t broke, don’t fix it” anytime we can get away with it.

Besides, tearing up a park to fit a dual slalom course is a bureaucratic nightmare that requires time, bags of money, hearings, permits, and contractors.

These are all things neither of us has.

However, if you can build a course using the trails you have, then with a little thought and creativity, you can re-purposing a section or two into something no one ever thought could happen.

I did the same thing with Collegiate Super-D.

Was it perfect?


But was it fun?

Ooooh, yes!

Experimenting with course design using existing trails is a blast since you don’t have to do any hardcore trail work.

So we’re going to build this dual slalom course out of existing trail too.


Here we go!

Have a design model in mind

Let’s use the Subaru Sea Otter Classic as our example for how to create a dual slalom event.

We’re not trying to build something as grand as Sea Otter’s dual slalom course, but it is a great model to consider when we put our event together.

If the Subaru Sea Otter Classic is a little much to take in, then the Mammoth Kamikaze Bike Games might be more your speed.

Smaller than the Sea Otter, but just big enough to be useful in getting our minds focused on dual slalom thinking.

To round out our look at dual slalom promoter’s, a local favorite here in the Mid-Atlantic is Gravity Soul in Frederick, Maryland.

They work a local dual slalom event in the Fall and are connected to the Mid-Atlantic Cup (MAC) Dual Slalom Series.

Having lots of options to choose from is the key point here.

Our first model is a big event that feeds pro/elite category riders into USA Cycling’s National Gravity Mountain Bike Championships, while the other two are West Coast and East Coast examples of regional USA Cycling Sanctioned dual slalom events.

These are all great examples to consider when building our course because they span a wide range of course designs, schedules, and turnouts.

Each one has an element that we can learn from and possibly use in our own race.

Two possibilities that jump out at me after reviewing these races:

  • Dual slalom popularity is on the rise
  • Having more than one kind of race discipline at your event can work

For now, I’m only going to focus on setting up a dual slalom race.

But the idea of having more than one race discipline is interesting.

More on that later.

Time for more dual slalom planning!

Know the basics

When is comes to professional dual slalom courses (e.g. Sea Otter Classic), I’ve noticed a few characteristics that all dual slalom courses seem to have in common:

  • There is some kind of big hill — not a mountain — just a hill that riders start on
  • Both tracks are side-by-side, with some identical to each other
  • Each corner or turn has a slalom flag that requires the rider to go around it, just like in alpine skiing
  • Steeper events require full helmets, while flatter events do not
  • They all have some kind of mechanical gate that opens at the start
  • They all appear to have some kind of timing gear to record finish times

Cool. That seems to be most of the at-a-glance sort of details that you need to think about when looking for a trail section that matches.

So far, we’re looking for some hills to give us that gravity feel, and we need the trail sections to be side-by-side in some way.

What is the distance between those side-by-side trails?

Good question!

If we consult our model, we see that Sea Otter dual slalom trails have about 2-3 feet between them in most places.

That will be difficult to find in a local park. But we might find some trail sections that are part of a loop.

These might be 20-50 feet apart, but if riders can see each other, that could work.

After reviewing all sorts of course designs, a few things are clear.

First, you don’t need big turn berms or a huge hill to build a course.

Second, everything does not need to be dirt. Grass hills work just as well as dirt hills.

In fact, you can use boundary tape and poles to build a curvy slalom right down a grass slope.

It’s not elegant as Sea Otters’ hand-made course, but it’s simple.

Simple is good!

Third, the hill doesn’t need to be super big, nor does the course need to go only downhill.

Dual slalom can have a bit of cross-country in it, similar to the Super-D.

However, take this point with a note of caution.

If you want gravity riders to take you seriously, you should aim to have it go mostly downhill.

But that being said, biker bumps, off-camber turns, and twisty up and over’s are all legitimate course dynamics.

Take what you know about your audience when deciding on how much “cross-country” you can get away with into your dual slalom course.

No matter what, your goal is to be the king or queen of flow.

Don’t include anything extremely technical, and stay away from features that would require lots of braking (e.g. 90-degree turns or big rocks).

Flow the course for about 100- to 200-yards, or what you ride in about 1-minute.

If you can find that kind of trail, then you have the makings for your first dual slalom course.

What else do we need?

Understand the course markings

We can make slalom flags with cardboard and stakes.

A bundle of long, wooden stakes is about $5.00 at Lowes/Home Depot, and we can use cardboard moving boxes in a pinch (which you can find for free if you know where to look).

Wood stakes are not very forgiving if you hit them, but plastic PVC pipe might be. PVC pipe is “bendy” too but cost a bit more.

I’ve also seen plastic boundary stakes used to, but it will probably come down to what works best for you.

I have a whole garage full of plastic boundary stakes, so that will probably be my stake of choice.

If I think about my course design, I’m probably going to need about 200-yards of trail length to have a good run.

This means I need roughly 10 slalom flags per run — 20 flags in total.

Sea Otter alternates flags from left to right sides of the trail, usually on the inside of each turn or bend. For us, that would depend on how twisty our trail sections are.

Sea Otter also uses color flags to let riders know which lane is which.

Blue for the left lane, red for the right. We could use any color we want, considering that these flags are mostly used for trail marking and branding.

You could even use t-shirts stretched between two boundary stakes (with your logo on them of course — never miss a chance to show off your brand) as the flags, just so long as you can tell the difference between lanes.

Getting them started and timed at the finish

Our model races are somewhat high-tech.

They have electronic starting bells, automatic drop gates, and synchronized clocks.

All that equipment is expensive.

How do we bootstrap our dual slalom race on a budget if we have to buy all that gear?

Well, let’s work through this one chunk at a time.

Starting with the start, we need to think about what is important.

To make it fair, we need to launch both riders at the exact same time.

To do this, we need a centralized method like a cap-gun, horn, big bell, or a siren. I like the idea of gun start, but that might make people nervous.

A big bell or loud sound would be a good start signal, even if the riders are 20-feet apart.

Looking through my garage, I found a scrap piece of sheet metal. Hitting it with a hammer created a really nice thunderclap.

In the open, this sound could be very effective in starting the race. It’s low-tech and cheap, making it a possibility.

If you have a nice portable speaker (e.g. Jawbone), you could use your mobile phone to create a loud beep or bloop that both riders could hear.

Timing is a bit more tricky since we need two kinds of timing: qualifying times and heat finishing times.

A nice solution for finding qualifying times is to coordinate launch times and synchronized stopwatches.

The start could launch riders on-the-minute, with the finish recording the time based on which minute the launch took place.

Another qualifying timing option is radios.

If you’re doing this in the boonies, mobile phone service might be spotty at best.

A simple hand-held radio connection between start and finish can be used to keep everyone on track with when to start the clock.

If you have radios, radios might work. But if you don’t have radios, and mobile phones don’t work, on-the-minute appears to be a good option for our race.

Fortunately, finishing times are a bit simpler.

At other races I’ve been to, the clock does not start until the first rider crosses the finish line.

As long as the start was fair, no time is recorded until the first finisher crosses the line.

Then the clock does not stop until the second rider finisher crosses the line.

This makes finish times focused only on the time between the first and second rider crossing the finish line.

For our race, that seems like the best way to do this. It removes time synchronization issues and makes timing all about the finish.

I will take easy, please!

We have to remember that in a dual slalom race, seconds is not the number we care about: milliseconds are.

Your stopwatch needs to be able to record milliseconds, and your timers need to be thinking in milliseconds.

Race winners will actually come down to very tiny numbers.

If you can launch riders in a fair way, and get an accurate time at the finish, you will never need super fancy timing gear to run a dual slalom race.

Now we need some rules for directing our race

What are the rules to our event?

What DO we have to have to be considered an official dual slalom course, and what are only “guidelines” that we choose or refuse to follow?

The first stop in exploring this topic is to go to the official source for all things cycling: USA Cycling.

USAC maintains a serious rule book on just about every mountain bike discipline, including dual slalom.

Since our model is a USAC sanctioned event and uses USAC rules and officials, we’ll take a look at the USAC rule book on dual slalom.

In 2013, USAC considered dual slalom as this:

    Dual Slalom: A gated gravity competition where two competitors race head-to-head down two similar but separate courses. Following a qualification round, riders race against each other in an elimination format (heats) to determine the winner. Dual slalom courses often will feature bermed corners, jumps, and other technical trail features.

Now, according to the 2015 USAC Rulebook Chapter 5: Mountain Bike Racing, dual slalom is a “gravity event” (Section 5E) with the following “guidelines” to conducting races:

    5E2. Dual Slalom. These are dual slalom guidelines; there are other options for conducting a dual slalom. Consult the race entry form and attend the mandatory riders meeting for more information.

      (a) Everyone will have at least one run for qualifying.
      (b) The fastest qualifier will be seeded against the slowest, the next fastest with the next slowest. See Appendix 3 for dual slalom seeding.
      (c) Racers will race head-to-head on each course. The rider with the faster combined time will advance to the next heat.
      (d) The rider’s bicycle must be stationary and contacting the gate (if used) at the moment of the start. Failure to comply will be considered a false start.
      (e) Alternating left and right, racers must ride around (not over) each gate, with both tire tracks passing on the outside of the gate. Gate judges located along the course, whose decision is final, determine this.
      (f) After the qualification runs, in the final heats, a rider may lose by no more than 1.5 seconds. This maximum differential applies to slow runs or penalties resulting from jump-starts, missed gates or other infractions. A rider who does not finish the run will be eliminated.
      (g) Ties in split times can be broken in the following ways: If overall times are recorded, the tie is broken by comparing the overall times on the course that both riders completed. If only split times are recorded the winner of the last run is the overall winner.

Looking at these dual slalom guidelines may make your eyes cross, so we need to break them down one-by-one and see which fits into our plan.

In directing our race, we should probably have a qualifying run.

This seems like a dual slalom standard and will help us with seeding who races against who.

It will not take long for riders to figure out which run (or lane) is fast, and which one is slow.

Even if the difference is in fractions of a second, mountain bikers, like baseball players, are superstitious.

But with that superstition, comes a grain of truth.

When you ARE dealing with fractions of a second, you may want that so-called “fast lane” to be your first run.

You want your first run to be your fastest — when you’re fresh — so that you get the best time possible.

Which means we need a way for riders to choose a lane, and make it fair.

One way we could do this is by allowing the first lane choice to go to the rider with the highest qualifying time.

Put out during the qualifier, and get your lane choice. Seems fair.

We could also make it random by using playing cards (high card chooses), similar to how BMX chooses lanes. That seems fair too.

For our race, we’re going to make it all about the qualifying time.

Ride hard in the qualifier, and get your lane choice.


And some rules for determining winners

Once each rider’s qualifying run is completed, we need to create a seeding list and figure out our groupings.

For example, since we seed riders based on fastest against slowest first, we would group eight (8) riders in our first round, like this:

  • 1st Place — 8th Place
  • 2nd Place — 7th Place
  • 3rd Place — 6th Place
  • 4th Place — 5th Place

Then we switch it up, and make both riders compete on the opposite course they started on.

This way both riders get a chance to ride both trails, again, making it fair.

What these guidelines do not say is the order in which these runs or “heats” take place.

Does each two rider group complete their heat’s first run, come back to the start, then complete their heat’s second run, before another group races?

Or, does the first two rider group complete their heat’s first run, wait for everyone else to finished with their first runs, and then, when everyone is finished going the first time, start the second run of their heat in opposite lanes?

The later seems logical to me.

It would give everyone time to rest between runs, and allow riders to take their time getting back to the start.

It’s a very Gravity way of thinking, and I think we’ll organize our heats that way.

We need to be conscious of the starting gate and have a few course marshals along each run to make sure no one hits any of our flags (which USAC calls “gates” — good to know).

The gate guideline about riding around and not over gates as they alternate left to right is interesting.

What if my trail does not do this?

We could put gates in areas that would require riders to navigate around them, creating a “mock” left and right pattern along the trail.

But this is a guideline, so I think we might just acknowledge that our existing trail sections have limitations that include the number of times we can alternate between left and right gates.

Having gate judges along the course at each gate seems like overkill too.

Maybe place one or two in key locations, but having 10 judges along our course will not work.

The last two guidelines are confusing.

The tie breaker guideline requires some math, and when dealing with final runs that are just milliseconds apart, you’re going to want a way to break ties.

However, the “maximum differential” of no more that 1.5 seconds is tough to understand.

This is a guideline that I think tries to control how a winner is determined.

Because we’re only recording finish times, the winner is determined by the combined time on both runs.

During the first run, if the winner crushes his opponent, the maximum time his receives between riders is 1.5 seconds.

This way the second rider still has a chance of beating the first rider, so long as they beat the first rider by more than 1.5 seconds.

Why is dual slalom done this way?

Riders will crash, flat, blow their start, or cramp up at the most unexpected times, allowing the other rider to take full advantage of their opponents issues and create a lead bigger than 1.5 seconds.

Because both riders will have their two times compared before a winner can be determined, a rider with a more than 1.5-second lead would be impossible to beat during the second run.

With fairness in mind, the maximum differential of 1.5 seconds gives the rider that suffered the complication, a second chance, provided they finished the course in the first run AND beat their opponent by more than 1.5 seconds.

From what I’ve experienced when attending dual slalom races, the maximum differential only counts on the first run. Once the first run is over, the second run stands by whatever difference there is between riders.

This makes the maximum differential rule apply to first runs only.

So, despite the complexity of this rule, it looks like a good one to include in our race. And for the sake of simplicity, we’ll only apply it our first runs.

Done and done.

Other rules that we need to consider

Sometimes we overlook the entry requirements for our riders.

Dual slalom is not an ordinary kind of race. It has its own rules, but it also falls under the purview of “gravity” mountain biking.

The result is extra rules for participants of dual slalom events that has everything to do with rider safety.

Unfortunately, these safety rules can be a hindrance to participation.

The first one we need to review is special helmet requirements.

USAC changed a bunch of rules a few year’s ago, requiring several gravity and downhill disciplines to have full-face helmets, just like BMX riders.

According to the 2015 USAC Rulebook Chapter 1: General Regulations, dual slaloms special helmet requirements read as follows:

    1J2. Helmets. For MTB downhill and 4X events, a full-face helmet must be worn. Full-face helmets must also be worn for Dual Slalom at National Championships.
    1J3 Padding. For all MTB gravity events, additional padding is strongly recommended. Examples: body armor, elbow and knee-pads and full finger gloves.

Reading these rules is like putting a puzzle together.

At first is sounds like a full-face helmet is required by all riders in our event.

However, the fine print states, “full-face helmets must also be worn for Dual Slalom at National Championships.”

Our race is certainly NOT a national championship. Nor is it downhill or 4X (Fourcross) event.

So if I read this rule correctly, the only time you need a full-face helmet is if you are racing the dual slalom event at a USAC National Championships.

Wearing padding is all about rider protection. Yet, according to USAC rules, padding is considered an “only if you want it” recommendation for our dual slalom riders, not a requirement.

I don’t know many mountain bike riders that ride without full finger gloves.

You’re kind of a knucklehead if you race without them.

But full-plate padding is the kind of thing I only see hardcore downhillers wear.

Regardless, USAC states that full-face helmets are “recommended” not “required”.

Since we want as many riders to attend our event as possible, we’ll make that our policy.

Our event will not require full-face helmets or padding but will recommend them.

Determining a winner

The USAC dual slalom guidelines for determining a winner are simple: The rider with the faster combined time will advance to the next heat.

That means in your final heats, the one that would advance, then becomes your winner.

After our eight (8) rider round example from above, our second round, which now only has four (4) riders, would look like:

  • 1st Place — 4th Place
  • 2nd Place — 3rd Place

The winners of these two heats will face off in the final round.

This will give us the 1st and 2nd place.

But what about 3rd place?

This is determined by a heat between the two losers of the second round.

The losers will face off in a final round to determine 3rd place (if you are going 3-deep).

Since we are going to provide awards to only the top 3 riders, our third round will be a heat of the two losers, followed by the podium heat against the two winners.

These are the rounds that will require us to understand how we will break any ties.

Fortunately, USAC gave us a rule for that too (check out Step 5 above).

Ties are not that rare in dual slalom, so make sure you read that USAC tie-breaking rules one more time.

Your brackets need to be finite

Our brackets for running a dual slalom event will work out best if we have an even number of riders with a known total of bracket slots.

Some events only have a certain number of bracket slots, and only the top qualifying riders get placed in those slots.

This means if we have a limited number of slots in our bracket, only a certain number of qualifying riders will make it into the first round, while the rest will not.

Two reasons why this is a good idea.

The first is that it will create a more exciting qualifying round.

When riders need to put out in order to secure a slot in the bracket, it will make them ride hard.

Riders going full out will give spectators something good to watch.

The second is that it gives you a fair way to keep your event on schedule by limiting the number of heats you have to direct.

A known number of heats can provide you with a rough timeline to build a schedule around.

There are only so many hours in a day, and a qualifier alone may take you 2-3 hours to complete.

However, if you do end up having an uneven bracket, that’s ok.

No riders will have to ride alone in the first round.

Instead, by determining the finishing times of each qualifier, we give the fastest qualifying rider the equivalent of a “first round bye”.

For an uneven bracket, this seems like a fair way to go forward.

You could switch it up and give the slowest rider the bye, but then you might have riders sandbag your course and “race to the bottom” for that slot.

That’s no way to run a race.

No, the fastest rider in our race will get that coveted first round bye if the bracket turns out to be uneven.

Build a bracket board for all to see

A known number of heats will allow us to set up a bracket board in advance.

64, 32, 16, 8 — whatever you decide the maximum bracket number to be will hopefully give you an idea on how big your board should be.

Once you know the size, you can use a portable whiteboard (i.e. dry erase board), chalkboard, or plywood sheet, to create a visible bracket that riders can consult between rounds.

We’ll start out with only bib numbers at first. But later on, we can get fancy by creating pucks made from cardboard, to show which rider is in which bracket slot.

Each round, we will advance the winners and give everyone attending a visual sense of how the race is progressing.

If we have an announcer, this will give them a way to call up each bracket to the start and narrate the play-by-play.

Officials benefit from the board too, by allowing timers to clear the slate between rounds.

Once posted, the last round’s results will be available for all riders to see, and allow for any disputes or challenges.

With the board being used as the break between rounds, it keeps the race going by providing a constant pattern of:

  • Start the race
  • Switch lanes
  • Race again
  • Post results
  • Ready the next round

You can also use this board to start showing rankings.

As riders get eliminated, they start to fill in the lower places between 5th and 64th (or whatever your total number of racers is).

Just remember that riders that advance to the next round will always be placed higher than those that did not.

Putting it all together

I think I have everything I need to start building my first dual slalom race.

I have some good examples to pull from, and enough images of existing course designs to know what kind of terrain I need to be on the lookout for.

I’ve already scouted out a park that contains a section of trail that perfectly parallels another section between two hills.

It’s not too high, nor too low, and provides great visibility for everyone attending.

Plus it has existing trails that are naturally aligned for what we need to do, requiring minimal trail work to get them ready for racing.

I’ve decided to use the same plastic stakes we use for taping cross-country borders.

They are lightweight, flexible, and cheap. Plus, after looking at several course designs, they make great lanes when using only survey tape.

Gates will be limited to cardboard and duct tape connected to two plastic stakes each.

I’ll use color square print-outs to code each lane by attaching them to the front of each gate.

Temporary but cheap.

We decided to do the on-the-minute timing for qualifying times, and only time the finish during heats.

We’ll need to supply the finish line a few stopwatches that can do milliseconds, which might be our only significant equipment expense.

Getting good times is important, so this expense is justified.

Finish line timing should be redundant, so having a pair of timers on each lane, with a master timer recording all splits should be fine.

With a USAC permit, we could have USAC officials time our event.

But USAC officials are not cheap, so this is an expense that you need to consider only if you have the resources and the need for official timers.

With timing taken care of, we will launch racers with a sheet metal gong, or possibly a siren from our mobile phone through a speaker.

We only need one start judge per lane, to make sure nobody jumps the start and a master starter.

I like the concept of a piece of plywood just set across the gate.

Cut to be only 1- or 2-feet high, and about 4-feet long, this could rest against two wooden stakes (since plastic stakes would be too flimsy).

At the starting signal, the riders would simply push away and “roll over” the plywood as they launched.

We could even get a little more creative and build a start box that placed the plywood on a hinge.

Either way, it would make it very obvious to the judges if a jump start took place.

Another option is to hold the back seat of the rider until the start signal.

This is a super easy solution to employ if you don’t have a gate but would require a few more volunteers to pull off.

Either option is low-tech but effective.

Next, comes our rules, which USAC helps us out with.

We know how to set up our race day schedule by first having a qualifying heat for all riders.

Then we fill out our brackets with fastest verse slowest rankings and allow the faster riders to pick their starting course.

We also know that we are only going to recommend full-face helmets and padding, not require it, which should help with our registration.

Once we are all set up, we start the first round, making each group of riders complete their first run before coming back to the start to complete their second.

This way we can continuously launch riders without having to wait for them to return to the start until their next run.

It gives riders a chance to rest and regroup before doing their second run and allows the race director to account for everyone’s time without long delays.

Meanwhile, we start recording finishing times and update our bracket board with the results we do have.

This continues until we have a winner.

Once we have winners, we hold an awards ceremony, let riders climb the podium for their awards and pictures, and conclude our race.

Easy plan for an easy day.

What comes next?

Is that seriously all it takes?

To build a dual slalom plan? Yes!

However, this is only our plan.

To implement our plan, we need action!

That’s where we start to recruit manpower to scout our venue, and do some course experimentation.

When we’re satisfied with where the race will take place, we pick a date, work out the details for drafting our permit, start selling our event to our target audience, and prepare for our race day.

This plan is just the first step in getting our first dual slalom race off the ground, but it is a critical step.

Especially when we realize that it doesn’t take that much to build this kind of race from scratch.

We don’t need fancy or expensive to make it good.

All we really need is the initiative to create the plan, and the motivation to see it through!

And now you know.

Posted by Kyle Bondo

Kyle started Reckoneer with the simple mission of helping those who want to become race directors and learn the mechanics of outdoor recreation engineering. Kyle demystifies outdoor racing with over 20 years of endurance and outdoor industry business knowledge. Combined with his top-rated podcast Merchants of Dirt, dozens of articles, lessons, and infographics, Kyle has made Reckoneer the premier educator in outdoor event management. Build better races today!