There are a variety of different types of endurance events. This is based on surface as well as format. Below are descriptions of the main types of endurance events and some examples.
Mountain Bike Races
Gravel Races
UltraCX
Bikepacking
Touring
Brevets
Stage Racing
Timed Events
Marathon and ultra-distance mountain bike (MTB) events are single day events over 50 miles. Most MTB events stop at around 100 miles (the Vapor Trail 125 being an exception). When events get much over this distance they take multiple days or at least one overnight and thus become bikepacking events or stage races.
Mountain bike events follow primarily singletrack, but many have some amount of gravel, B, or jeep road. The ration of singletrack to road can vary greatly between events. The High Cascades 100 in Bend Oregon boasts over 80% singletrack. (I would say that was a conservative estimate.) The Leadville 100 by contrast follows a variety of roads and jeep trails and has very little singletrack.
Many mountain bike races have some level of support. Most with entry fees have fully stocked aid stations. Other events such as those in the Southwest Endurance Series are fully self-supported. When you’re riding singletrack for 100 miles carrying enough stuff to last all day verses just enough to get you to the next aid station makes a huge difference.
Examples: Leadville 100, High Cascades 100
Gravel races, also called gravel grinders, are long distance events (usually a metric century or more) that follow primarily gravel roads. They almost always involve some pavement connector, but efforts are made to keep the pavement to a minimum. Some events have more or less B road, doubletrack or lite jeep road.
While many folks do ride a mountain bike in gravel events, the route is usually appropriate for a cyclocross bike. Very few gravel events contain singletrack and almost never involve hike-a-bike unless it involves a minor stream crossing or weather makes a B road impassible.
A notable exception is the San Ysidero Dirty Century. This event involves ~85miles of gravel followed by 15 miles of singletrack. A CX bike is fully capable of handling the gravel and is probably faster, but the singletrack at the end far and away favors a mountain bike. In 2012 I did it on my cross bike. The first 90 miles (I went off course a bit and added miles) took a respectable six hours. The last 15 miles went at a sluggish 3 hours. Any time I might have gained on the lighter CX bike during the gravel was quickly lost on the singletrack.
Classic gravel grinders
UltraCross, or Ultra CX, racing is a relatively short event. These are multi hour events, but currently do not really meet the ultra-endurance criteria. There are also very few ultra CX events. In the US these are all in the Eastern states. Modeled after early cyclocross events and the long standing Three Peaks race in the UK, UltraCX events are typically 30-60 miles. They involve almost all surface types, but they are either primarily or exclusively done on a CX bike (depending on race rules). They usually have at least one section that requires the rider to dismount to carry their bike over a natural obstacle or hike-a-bike a section of the route. For example Three Peaks describes their route as “38 miles, of which 34 is rideable (20 cross and 18 road) and 5000 feet of climbing.”
Examples: Three peaks in the UK, The envents in the American UltraCross Championship Series
Bikepacking events are self-supported multiday events typically on backroads or singletrack that favor a mountain bike. Most bikepacking events involve a fixed distance from start to finish and the first to cross the finish line wins. Events range from 250 miles to 2750 miles for the tour divide.
Surface conditions can vary widely. Despite it’s impressive length, the Tour Divide has very little singetrack (less than 1%) and presents very little riding of any technical difficulty. Alternately, the Colorado Trail Race is primarily singletrack, some of which is very technically challenging.
The key component of Bikepacking is that the rider spends at least one night out and carries all of their own equipment without support. Of course you can go bikepacking without being in a race too.
Examples: Arizona Trail Race 300/750, Tour Divide (2750 miles), Colorado Trail Race (550 miles)
Bike touring is a bit different than bikepacking. While one might choose to tour on any surface type, touring is not in a race format. Bike tourers take any amount of time they desire to reach their destination and there is no restriction about support. Additionally, since tourers are not racing there is usually less concern about weight. While you can certainly use the information here to help you tour, the rest of the content is not aimed in that direction.
Examples: The Adventure Cycling Association describes a huge number of classic tours in North America.
A brevet, also known as a Randonneuring or in the UK Audax, is a popular race format that, with European roots. Brevets are long events of 200k+ up to well over 1000k but almost all of them follow paved roads. The brevet format involves leaving a checkpoint and making the next checkpoint by a designated time. These checkpoints are referred to as “controls”. Brevets may be supported, or self-supported. They also may occur in a single push or follow a multi-day format.
Brevets are governed by an international or local sanctioning body that places requirements on riders and keeps track of placement. For longer brevets riders must prove their worth by showing their time in previous brevets. For example to enter the Colorado High Country 1200, a 1200k brevet in CO, the rider must have completed a 200k, 400k, and 600k brevet within the previous calendar year. In contrast to enter the 2700 mile Tour divide all you have to do is sign up and show up. The Audax Club Parisien (ACP) is the international governing body.
As brevets often semi supported road rides you won;t hear too much about them on this site. There are two notable exceptions: The Kiwi Brevet and the Great Southern Brevet. Both of these events take place in New Zealand and despite their name are closer to bikepacking events than an American or European Brevet. Both events take place on dirt roads and trails of varying quality.
Example: Paris-Brest-Paris the original brevet.
Stage racing involves racing for multiple days. The Tour de France is probably the most famous road stage race, but there are many mountain bike stage races. To my knowledge there is currently only one gravel stage race set to run its inaugural event in 2012.
Mountain bike stage races are all fully supported events and run from 3 to 9 days. They are typically expensive to enter and always have support, but fees do not always include things like lodging, meals or transportation. Check on the details of the event you may be interested in for more information on what is included and what’s not. There are wide differences in what they offer and the costs of extras.
Stage races are usually but not always point to point events. The Breck Epic in Breckenridge, Colorado starts and leaves from the same location every day, but due to the amazing array of trails offered in the area it takes a different route each day. In contrast most events begin and end in a different location each day, so a racer’s equipment and belongings must be transported as the ride progresses.
One amazing feature of stage races is that they cover a lot of ground and they’re held all over the world. There are stage races on every continent except Antarctica, so if you’re keen to ride and race this format it’s an amazing way to see the world.
Examples
- The North Woods Adventure (Gravel, Minnesota, USA)
- BC Bike race (British Columbia, Canada)
- Trans Rockies (Alberta, Canada)
- Trans Andes (South America)
- Iron Bike (Europe)
- Breck Epic (Colorado, USA)
- Trans-Sylvania (Pennsylvania, USA)
- La Ruta de los Conquistadores (Costa Rica)
- Absa Cape Epic (South Africa)
These endurance events are timed mountain bike events that involve participants riding laps on a course. (Note there are road bike based timed events as well.) The event winner is determined by the number of laps traveled. These events usually last 6, 12, or 24 hours and may be conducted by a single individual (solo category) or by a team. Laps are in the range of 7-15 miles with times for each lap varying greatly depending on the difficulty of the course.
Because the event involves multiple laps riders have support. You will very likely be providing your own support, but you’ll pass your team or aid on a regular basis. In this sense the logistics are very different from a long bikepacking or even long gravel event.
Examples: 24hours in the Enchanted Forest
The Endurance Experience 
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