Winter grooming options for urban trails

Fat bike on groomed trail. ©Vila, WI

​For a good section of the country, winter time brings out the hardiest of the hardy: winter bikers.  It takes a special type of person to ride their bike in the winter.  But it also takes special work to make the trails fun for riders.  That special work is known as grooming.
Grooming for winter use is becoming more regular and normal across the snowy north, but still can fall into the “black art” territory.  Why groom?  What types of grooming are there? 

​Why Groom?

​Grooming makes winter riding much easier, even with a fat bike.  This is helpful as well-groomed trails will encourage users of all abilities to use the trails more often.
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The one added bonus of grooming is more psychological than physical: it changes user’s expectations of the trail.  Without grooming, winter trail use can be very chaotic, with this user doing this and that user doing that.  However, with grooming come rules and controls.  Trails are open or closed based on weather conditions.  Grooming makes for clearly defined paths in the snow with less “meandering”.  All this reinforces the idea to users that the trails aren’t just a free-for-all, the trails are a thing with constant care.

​When not to Groom

​Are their times and places where grooming is a bad idea?  Yes.

First, grooming reduces the number of possible uses on a trail.  Bikes will have to have at least 3” tires with 3.8” being the preferred width.  Standard hiking is out the door as users will post hole the groomed surface.  Dogs are certainly a no-no.  All this can be an issue with trails in an urban area as the sheer volume of winter users means excluding entire categories of uses will remove thousands of people from the trails.

Second, in order to really groom without damaging the underlying trail, the ground underneath the snow needs to be frozen.  Not “oh, it seems a bit stiff” frozen, but something more like “granite hard” frozen.  If this only is happening rarely where you live, or even based on the time of the day, grooming might actually do more damage than good.  This is especially true if your winter days tend to whipsaw between the freezing point and sub-freezing.
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Third, and this can’t be stated enough, grooming is hard work that will require some dedication by volunteers and staff.  If your organization can’t handle the dedication to grooming that will be required, it’s best not to groom.  Grooming is typically best done in the evening as temperatures fall. This will require some number of people running around the woods after dinner or when the rest of the town is heading to bed.

​Method of Grooming: Human-Powered

Stomp, stomp, stomp

The first method is likely the one you are already using: human powered grooming, probably with snowshoes.  Of all the grooming methods, this is the simple one.  Put on snowshoes and walk the trail.

There are some tricks to this method as random foot falls make for an uneven surface.  Its best done with two or more people in a row, with the snowshoers offset a bit.  That is, the foot fall of the person behind the person in front of them is one-foot width to the left or the right of the person in front.  The Ozaukee County Mountain Bikers has a great infographic on how to groom using snowshoes.

Showshoe grooming instructions

​The snowshoe grooming can often be enhanced with some type of drag.  This can be an old tire, a sled with weight or even the pan from a garden wheelbarrow.  There are also commercial grooms made for this exact purpose.  The most common of these are those produced by MyTrailGroomer.  If you have to groom by human powered means, it’s hard to beat their groomers.  The grooms include scratchers and combs for a professional look.

If you are doing human powered grooming, the one thing to remember is the volunteer time and effort needed.  It requires an army of dedicated volunteers.  What some locations have done to minimize this effort is to partner with snowshoe clubs, schools and youth organizations.  Numbers is the key to the human powered grooming game and the bigger the pool of volunteers, the happier everyone will be.
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In urban trails, especially larger metropolises, making it known that snowshoers are welcome and encouraged can alleviate the numbers issue just by itself.  For suburban trails or smaller urban areas, it might require a set day or night for snowshoeing.  This would include club volunteers, but also others who want a group snowshoe experience.

​Method of Grooming: Tracksleds

Trail Tamer tracksled

Tracksleds are a simple device.  Basiclly, they are a snowmobile track and an engine with a handlebar on the rear, allowing the user standing or sitting behind the machine, to move the tracksled like a push lawnmower.  There are several types and manufacturers, from the Cadillac of the tracksleds, the Trail Tamer to the workhorse Snowdog.

Tracksleds have a huge advantage over other machine grooming methods: they are very narrow and can turn on a dime.  This makes them about the only machine grooming devices that work in tight and narrow hand cut trails.  Even Rokons, which have similar turning radii as mountain bikes find themselves in situations where they can’t make certain corners.

Tracksleds have two things that must be factored in when considering them for grooming.  The first is that they do require a lot of body English to move around.  The bigger and longer the tracksled is, the harder it is to move.  Be prepared to have pecs and biceps of a body builder by the end of the winter.  The second thing to consider is that currently, the grooms have to be home-made.  Snowdog, the company which makes a series of tracksleds for sale here in the United States, does have a groomer for sale.  But it is a simple pan groomer than may not work for every snow condition.  There isn’t a way to attach a snowmobile groomer on a tracksled.  Everything must be custom built.
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Besides the ability to groom narrow and twisty trails, tracksleds have another big advantage: they fit into the bed of even the smallest pickup truck.  This makes them ideal for locations with multiple trails to do and the ability to afford only one machine.

​Method of Grooming: Rokons

A Rokon in stylish army green

Rokons are a brand of all terrain 2-wheel drive motorcycles.  They have been produced since 1963 with little changes.  There is really only one manufacture, the name-sake: Rokon.

Rokons have nearly the same dimensions as an extra-large 29er full-suspension bike, being just a bit longer.  However, they don’t have same turning radius, Rokons obviously being a bit larger.  Also, the turning radius of a Rokon depends on the traction of the front wheel.  When the front wheel (which is powered) has less traction, the turning radius increases.  This is important to remember if your trail system has switchbacks.  Yeah, a Rokon might be able to go around when its dry, it might not be able to do the same when its snowy.

With a good set of snow chains and the more aggressive tires, Rokons can handle all but the deepest snow dumps.  If you live in an area where the average snow is 4”-6”, Rokons will be fine, though for stickier snow it might require two passes: one to break trail, one to groom.

Rokons can pull a surprising about of weight, so long as the friction of the groom is low.  Roller grooms, scratchers and sleds can be pulled with a Rokon.  However, for grooms with a lot of friction, they will cause the Rokon to bog down and loose traction, especially on uphill segments.  This means grooms with a lot of teeth and with bits that bite into the snow cannot be pulled as the friction is too high.
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Rokons have one huge advantage over the other machines on this list: they can be used year-round.  For moving tools and equipment around for trail work or events, Rokons can be the ticket, able to go nearly anywhere a mountain bike can.  The Rokon company even makes a bob style trailer that can haul all your tools and more.

​Method of Grooming: Mini-snowmobiles

A Irbis mini-snowmobile

Though rare in the United States, company’s like Irbis do sell mini-snowmobiles (called ¾ snowmobiles).  They are not kids sleds, but small snowmobiles designed to be used by adults for utility purposes.  They aren’t very powerful, in fact, they suffer from the same problem of a Rokon: grooms with a lot friction will bog these down.

So, what is their advantage?  Simply put: cost, ease of use and simplicity.  Typically, they cost right around $2,500, compared to $7,500 to $10,000 for a utility snowmobiles.  They often use engines that are similar to a garden tractor, meaning they are less fussy with maintenance.  Additionally, they don’t have a lot to them.  Start them, throw them in gear and go.

Like a normal sized snowmobile they will require a snowmobile clear zone and other winter groom compliances.  We’ll discuss winter groom compliances a little bit more with full-sized snowmobiles, so hang on for that.
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Mini-snowmobiles can be used as a primary grooming device, though for some snow depths and wetness combinations, they are a two-pass groom. The first pass is without an attached groom and is to provide a base for the second pass with a groom.  Where they really make sense is as a conditioner or refresh groom.  If the snow in your area comes in a bunch of relatively small (<6”) snowfalls or if you get a large amount of snow early winter and then a long period with little snow till spring, running a full-size sled is overkill.  A smaller, lighter and easier to use sled that can pull a roller, scratcher or sled grooms is an advantage.  One little talked about issues with big grooms that churn the snow up every time is that they can over churn the snow and increase the likelihood of ice forming or churn snow till it loses its ability to bind (sugar snow).  For instances where you want to incorporate that 2” snowfall into your existing base, a lighter sled pulling a rubber-tired roller is more than adequate.
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Another advantage of these sleds is for volunteers with smaller frames, including women and teenagers.  They tend to weigh just over 300 lbs, or 1/3 less than the smallest utility snowmobiles.  While this cuts the traction down a bit (see previous comment about bogging down) in also means you don’t have to pump weights to apply body English to the machine on the trail.

​Method of Grooming: Utility Snowmobiles

A Ski-Doo Tundra, one the best utility snowmobiles

The big momma of the grooming machines, utility snowmobiles can handle just about anything you can throw at them.  They are also the most expensive option.

To have a singletrack mountain bike trail to be groomed by a snowmobile the trail must be Winter Groom Compliant.  What does that mean?  It means the trail must have a clear zone, free of items that could present a hidden danger to the snowmobile (and the grooming volunteer).  Radii also need to be considered, as a snowmobile with a groom can have a turning radius of around 12’.  This means switchbacks and tight corners cannot be groomed with a snowmobile.  This also means that some corners, like climbing/descending curves must be altered to allow for grooming.  It’s possible to have grooming bypasses, that is, sections of trail that are only used in the winter, though for certain features and hillsides, these get complicated.  This allows technical features for 3 seasons and a bypass for winter, where technicality is less important.

Utility snowmobiles can pull every type of groom, including the most aggressive styles with lots of teeth and biting sections.  They can also pull utility sleds for winter trail work, events or even volunteers.

However, it’s important to note that while utility snowmobiles are the top tier machines, they come with top tier requirements.  They need a place to be stored, licensed and require a higher level of maintenance.  Also, they do require skilled operators to be effective.
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With that being said, if you are going to groom, utility snowmobiles produce the ability to groom enormous amounts of trail relatively fast, almost always in a single pass.  That is not a minor bonus.  Knowing a 12-mile trail could be groomed after dinner and be ready to ride the next day without anything else being done makes things easy for the volunteers and the riders.

​Which method is for you?

Which option is best for your trail(s)?  Frankly, there is no one answer.

If your trail is less than 5 miles in length and you have several volunteers or can partner with other users and don’t have resources (money, storage, etc.) to have machines, human powered grooming is best answer.  Burning off the Christmas cookies or auntie’s pound cake is as free as it gets.  Do yourself a favor and get several drag-behind groomers to make it a little more professional.

If you have tight singletrack, maybe even a hand cut style, Rokons and tracksleds are the only real options.  Of the two, tracksleds are more conducive to bigger snowfalls.  However, its likely with both you will be working with a local machine shop to create your grooms.  There are just not a lot of grooms that can work with either one.

If you have a more open singletrack trail, then snowmobiles are the way to go.  For areas with lower snowfall-per-time amounts or where budgets are small, mini-snowmobiles might be the answer.  Where large snowfall occurs with many miles and the budgets can accommodate it, a full-size utility snowmobile can do a lot of work and do it fast.
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If you are planning new urban singletrack and you can foresee a day where grooming will happen, do yourself a favor and build the trail with Winter Groom Compliances.  It’s a type of future proofing that will never really come back to bite you.