GPHXO Mountain Bike (MTB) Orienteering
Rules and Tips


  • A helmet must be worn at all times while riding a bike
  • The race can be run as an individual or as a team
  • Mountain bikes must remain on designated trails and roads that are approved for mountain bike travel. These trails should be marked on the map as a thick black line, either solid or dashed. Dirt and paved roads appear on the map as per the map legend
  • The mountain bike may be ported (carried) off-trail or on undesignated trails, as part of a navigation strategy. It is more common to leave the bike alongside the trail at the "attack point" and navigate to the control point on foot
  • It is against the rules to navigate using a GPS aided device such as a smart phone. "Navigation" includes looking at a georeferenced map on your device to determine where you are on a competitive map. Cell phones may be used to log the track of the competitor, or to carry for emergency use.
  • Bike computers are allowed for measuring trail distance
  • Scoring (Score-O) Person or team with the highest score at the end of the time interval (2 or 4 hours) wins. A severe penalty (10 points per minute) will be subtracted from the score for a late finish. Control points can be visited in any order
  • Scoring (Classic) All controls must be visited in the sequence indicated on the map. The person or team that visits all controls in the shortest time wins.
  • Scoring (JOM-O) For the special case of JOM-O (a traditional Bike-o course integrated into a Score-O map), there are two scoring categories: the score-o score as described above, and a Bike-o completion time for any person or team that visits all of the designated Bike-o control points. See the scoring rules for a JOM-O

Riding Safety

The designated MTB "single-track" or "double-track" trails are usually shown on the map as a thick black line. Double-track trails are thicker lines than the single-track trails, For both single-track and double-track trails, there are three symbol types: A solid line indicates "fast riding", a smooth rolling trail; A long-dashed line indicates "medium riding"; A short-dashed line indicates "slow riding". Slow riding trails usually have technical sections that might include rock drops, steep terrain or exposure, loose rocks, or other hazards. Use care when selecting your routes and avoid areas that are above your skill or comfort level. Specific definitions for MTB map symbols can be found in the International Specification for Mountain Bike Orienteering

Also, just because a trail is marked as a solid line, this doesn't mean the that trail won't have any technical sections on it. Due to the scale of the map, it's impossible to map every isolated tecnical section. Always ride with caution, and dismount from the bike if you see a section that is above your skill level.

A safety whistle is also mandatory equipment. Whistles can be purchased from GPHXO for $1 each.



The course is mostly 'ride-able' single track and dirt roads, and a robust mountain bike (hard-tail or full suspension) designed for cross-country travel would be preferred. A riding helmet is mandatory equipment, and riding gloves are highly recommended.

A lot of advanced mountain bikers use a clipless pedal system to maximize power transfer and efficiency. If you plan to go off-trail a lot, be aware that it can be really hard on your biking shoes. Also, shoes make for clipless pedal systems will not provide as good traction as a sturdy pair of running shoes. You may want to consider switching out your clipless pedals for flats for this type of race

Riders should be prepared to carry enough snacks and water for a two or four hour ride. There is usually one or more unmanned waters stops on the course, but it is always a good approach to no rely on them completely. Likewise, riders should carry with them, as a minimum, tools to repair damaged tires.

The only special equipment needed is some sort of map holder. These can vary from the very simple (baggie mounted to the handlebar) to the very sophisticated (specialized map holders that can easily be rotated to orient the map ). Serious Adventure Racers will often invest in a specialized map holder such as this one. A word of caution: some people will put their map in a map case secured with a lanyard around their neck or shoulder. If you do this, make sure that the lanyard has some sort of "break-away" system that activates when only a few pounds of force is applied-you don't need a snagged map holder pulling you off of your bike!

Many bike orienteers do not use a compass while racing. A compass is extremely useful, however, if you need to re-locate yourself on the map. Carrying a compass with your gear is highly recommended. Compasses can be rented from GPHXO for $1 each.


Route Planning -- Good route planning is a key to successful bike orienteering. There will be a ~15 minute window before the race where you can plan your racing strategy.I Your goal is to visit all the controls in the shortest time, which means minimizing distance and climb. For folks who are not strong climbers, it is often a faster choice to pick a longer, less steep route than to take the most direct path to your destination. Also, a loop between control points may often be easier to ride in one direction than another. For example, you may want to ride down a steep descent rather than climb up it. For courses where you must visit all mandatory controls (a classic or a JOM-O), make sure that your route hits all of them--it is a very common mistake to plan and ride a route, only to find out that a control point was overlooked. Double check your route before you depart the start area, and check your punch card before returning to the finish to make sure you have all the mandatory controls. If you can interpret contour lines, use the topography to pick a better route. Finally, look at the line symbols for the trails that you will be following. Are there any dashed "slow riding" trail segments on your route? Do you plan to ride them or walk your bike? Is it better to go up the technical sections (better footing for walking) or downhill (less expended energy)?

Don't forget that you can port your bike off-trail if you think that reduces your course time. This can be useful when you want to get to a parallel-running trail, but there is no trail intersection for a long distance. Sometimes a quick porting dash will get you on the other trail faster than riding the long way around.

For a Score-O, keep track of how you are progressing relative to the plan as you ride. As you get nearer the finish time, re-assess how long it will take you to return with the remaining time, and make the appropriate adjustments to your planned route. There is a severe scoring penalty of 10 points per minute for returning late.

Navigate by "attack points" and "catching features' -- One technique that will speed up your navigation to off-trail control points is to take advantage of distinctive map features and navigate to those points as quickly as you can--these are your "attack points". Usually in a Bike-O, the attack point for an off-trail control will be the point at which you depart the trail. This could be a trail intersection, a distinctive bend in the trail, where the trail crosses a stream or hilltop, or something else. The key is that this point needs to be distinctive--if you pick a bend in a trail that looks a lot like other nearby bends in the trail, it will be harder to identify the attack point accurately as you approach it--so pick a good attack point. You may also find that it's really easy on a mountain bike to blow by your attack point and not know it. So your navigation plan should also identify a "catching feature" on the trail that tells you you've gone too far. This could be a power line, road or trail intersection.

Distance measuring -- Another new skill to master is measuring distance--both on the map and in real life. The map, of course, is to scale, but here are a couple simple ideas for quickly estimating distance: First, you can use the spacing between the magnetic north reference lines that will be drawn on a map. These will be drawn at a fixed distance (normally 300 meters) and you can use these as a local reference to approximate distance just by eyeballing it. This is usually good enough for coarse navigation. Second, check the fingers on your hand and see if one measures close to 1 cm in width across the fingernail. This would correspond to 100 meters on a 1:10,000 map or 250 meters on the 1:25k map. You can use this for more precise measurement without having to fumble for a ruler. If you are using a bike computer as the method for measuring distance, set it up in 'metric' mode, and then measure everything in meters--it's a lot easier than miles and yards.

Card Punching -- Another tip to save time is to have the punch card both securely attached and easy to access. Rather than stuff in a pocket every time you get to a control, consider attaching the bottom of the punch card to the bottom of your outer shirt with safety pins. In most cases, you should be able to reach the punch to the card without having to dismount the bike. Some people prefer to use a retractable cord or other method to minimize getting on or off of the bike to use the punch. Safety pins are available at the start/finish area.