Enduro Basics
Enduro racing is a unique test of your riding skills and your ability to do math at the same time. Unlike hare scrambles and GNCCs, the object of an enduro is NOT to always go as fast as you can and to be the first to cross the finish line. Instead, enduro courses are laid out such that riders must be at certain points (called checkpoints) at an exact time. Points are taken from the rider if he or she is early or late in getting to theses checkpoints.
Since time is a very integrated part of enduros it is important to understand the definitions of the various timekepping terms thrown around at an enduro. Especially since some of these terms are loosely muttered and used interchangeably. For example "keytime" can take on different meanings depending on when you say it. For the record, or at least this discussion, the following terms are being defined. The God of all time (goat) is the POSTED KEYTIME. This is the time to which everything is synchronized, all the checkpoints of the race are defined by this clock. This is the time usually referred to as simply KEYTIME. The event organizers will post this time somewhere so that everyone can synchronize their watches to it.
Enduros utilize staggered starts. That is, every rider is assigned a minute at which he will leave. Typically there are four or five riders per minute. Each rider must adjust his clock so that it reads the posted keytime minus his minute. For instance if the keytime is 7:30:00, the watch of a rider on minute ten should read 7:20:00. The time on the riders watch is the ADJUSTED KEYTIME. The rider then leaves the gate when his watch reaches the race start time (9:00 on this route sheet). Therefore, riders on minute 1 leave when the posted keytime is 9:01:00, and riders on minute 20 leave when the posted keytime is 9:20:00. However, in all cases, the riders watch reads 9:00:00 when he leaves so that he can compare it to the route sheet. Once the rider leaves, the adjusted keytime is also referred to as the elapsed keytime. That is, the amount of time that has elapsed since he left the gate.
Prior to an enduro, the riders are given a route sheet similar to the one shown at the left. These route sheets give the riders all the information they need for the race (except the location of the checkpoints!) Speed averages, mileage resets, layovers, gas stops and more are all shown on the route sheet. A typical route sheet list the mileage on the left, directions in the middle, and elapsed time on the right (also referred to as adjusted keytime since it is the posted keytime minus the riders minute). The time will be listed as either elapsed time directly (starts at 00:00:00) or as elapsed time plus the race start time. This route sheet shows the latter with a race start time of 9:00.
SPEED CHANGES
Speed changes tell the rider the pace he must maintain in order to stay on time. Notice that on the route sheet the riders start out at 30mph and then change to 18mph at 1.50 miles. Speed changes are used by the promoters to control how many points are taken from the riders in each section. In point taking sections, the promoters must balance the use of speed changes such that only the fastest riders can get to the check on time (called zeroing a check), and that they take at least a few points from the intermediate riders, but not too many from the novices. Tough sections usually will use a slower speed average. In timekeeping sections the speed average is set such that just about all the riders can maintain that speed average. Thus the rider needs to timekeep and be careful not to arrive at a checkpoint early (called burning a check).
RESETS
Mileage resets are points in the race where the rider should advance his mileage as indicated on the route sheet. These are used for several purposes. Resets are usually added at the end of a point taking section so that the riders can get a rest. Normally a reset will instantly put the rider ahead of time (make him early) so that he must wait for time to catch up. Notice on the route sheet at 17.55 miles there is a reset that puts the rider about 16 minutes ahead. As long as the rider reaches 17.55 less
than 16 minutes late he will be able to stop and wait until his clock reaches 10:05:40. Resets are also used just before road sections so that riders are put ahead of time so they don't need to speed on the road to catch up. They can also be used at gas stops to give the rider time to refuel and eat. In most cases the reset is used to put the rider back on time or ahead of time.
LAYOVERS and WAITS
Layovers are just speed changes where the speed is 0mph. That is, time keeps ticking away but the corresponding mileage remains the same. These are sometimes used instead of resets at the gas stops. The duration of the layover is specified in minutes. When the layover expires, either the previous speed in resumed or another speed is specified.
On this route sheet there is a layover for 20 minutes at 42.80 miles. The previous speed of 24mph is resumed after the layover. Notice how the elapsed time jumps from 11:04:00 to 11:24:00 while the mileage stays at 42.80. As with resets, the amount of time you actually get to relax depends on how late you are getting to the layover. For example if you get there at 11:14:00 (ten minutes late) you have ten minutes to eat and rest. At 11:24:00 you need to maintain 24mph again to stay on time.
BASIC TIMEKEEPING
In theory timekeeping is very simple. All that a rider needs to do is monitor his clock and odometer and make sure they coincide with the mileage and elapsed time on the route sheet. The real trick is doing this while dodging trees and rocks at 20 mph! Typically a rider will need to stop to get a reading of his instruments. Normally this will be at a trail marker because the time and mileage for trail markers should be on the route sheet. Techniques vary, but the rider will check his odometer (or use the mileage on the marker), find the corresponding point on the route sheet, then check his clock against the route sheet elapsed keytime. If his clock is behind the route sheet time he is early. If his clock is past it he is late. For example if a rider reaches 50.05 miles and his clock reads 11:41:08, he is 1 minute early; he shouldn't be at that mileage for another minute. However, if he gets there and his clock reads 11:47:00 he is late; he should have been there 5 minutes ago. This method of timekeeping is a slave to points on the route sheet. If the rider wants to know how he is doing and there are no markers around, he will have to do some interpolating. For example, if he is at 53.10 miles there is no entry on the route sheet. Therefore, he will need to do some math to figure out if he's early or late.
TIMEKEEPING TRICKS
A rider can take advantage of few simple tricks and rules to help stay on time and keep from burning checkpoints. Speed changes must be on even minutes. Note on the route sheet that all speed changes occur when the seconds of the elapsed keytime are zero. Also, each speed can be defined in terms of miles per minute (speed/60). For example, in a 24 mph section a rider should travel 0.40 miles per minute to stay on time. Therefore, a rider can monitor his progress by keeping track of how far he goes every minute. This requires the rider to continuously add 0.40 miles to his mileage every minute. This is sometimes referred to as riding possibles since checkpoints also can only be on even minutes. Basically, with this technique the rider chops up the course into 1 minute intervals. As his clock approaches the top of a minute he can check his odometer to see how he is doing. If he is near the next 0.40 increment he is on time. If he is past the next interval he is early, etc. This can fill in all the unknown points of a route sheet. However, this can get confusing if the rider loses track of the mileage or if the rider cannot stay on time.
TIMEKEEPING with a COMPUTER
Computers relieve the rider of the tedium of timekeeping. It gives the rider a second by secong update of how he is doing. Typically, the most used piece of information that a computer displays is the differential time, AKA diff time. This tells the rider how early or late he is in minutes and seconds. The diff time is the difference between the actual elapsed keytime and the calculated keytime which is based on the current odometer mileage. The convenient aspect of a computer is that it always displays the information, regardless of where the rider is on the route sheet. It fills in the entire race for him.
Computers also act as odometers and, of course, clocks. The accuracy of the diff time is dependant on the accuracy of the odometer. An advantage that computers have over mechanical odometers is that they can be tuned to match the odometer that was used to layout the course. One of the programmed entries is the tire circumference. This tells the computer how far the bike travels every time the tire rotates once. During a race the rider can adjust the tire size if his odometer does not match the course mileage markers.
Computers need to be programmed before a race. All the resets and speed changes are programmed into the computer as outlined on the route sheet. When a reset mileage is reached the computer automatically advances the mileage and calculates the diff time. More advanced computers allow the rider to enter his starting minute, the race start time and the posted keytime, so that the computer can calculate and display a countdown to race time. They will also have some type of routine that allows the rider to easily verify that the computer is programmed correctly. The time to discover that he missed programming a speed change is during programming, NOT 20 miles into a race.
Route Sheet
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* 1999 *
* KING PHILIP *
* ENDURO *
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0.00 SPEED 30 9:00:00
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0.00 L TAR 9:00:00
***RT 1A***
0.20 R TAR 9:00:24
***BEECH ST***
1.20 R TAR 9:02:24
***TAUNTON ST***
**********************
1.50 SPEED 18 9:03:00
**SPEED CHANGE TO 18 MPH**
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1.55 L DR 9:03:10
2.00 L TR 9:04:40
2.20 L TR 9:05:20
2.80 S TR 9:07:20
3.20 L TR 9:08:40
3.95 RESET TO 9:11:10
4.20 L TAR 9:12:00
***MADISON ST***
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4.20 SPEED 30 9:12:00
**SPEED CHANGE TO 30 MPH**
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4.45 R TAR 9:12:30
***RT 140***
4.80 R TAR 9:13:12
***THURSTON ST***
5.75 L TAR 9:15:06
***RT 1***
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6.20 SPEED 24 9:16:00
**SPEED CHANGE TO 24 MPH**
**********************
6.80 R WR 9:17:30
7.10 L TR 9:18:15
7.35 L TAR 9:18:52
7.70 R WR 9:19:45
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8.00 L TR 9:20:30
**THEN R TR
8.95 L WR 9:22:52
10.20 R TR 9:26:00
10.65 R TR 9:27:08
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11.00 SPEED 18 9:28:00
**SPEED CHANGE TO 18 MPH**
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11.15 R TR 9:28:30
11.65 L TR 9:30:10
12.10 R WR 9:31:40
12.70 L TR 9:33:40
13.55 S X TR 9:36:30
14.65 S X TR 9:40:10
15.20 S X TR 9:42:00
15.75 L TR 9:43:50
16.15 R WR 9:45:10
17.00 L TR 9:48:00
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17.55 RESET TO 9:49:50
22.30 R TAR 10:05:40
22.60 L TAR 10:06:40
***RT 1***
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22.70 SPEED 24 10:07:00
**SPEED CHANGE TO 24 MPH**
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23.55 R TAR 10:09:08
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**GAS AVAILABLE**
**IN PARKING LOT*
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23.75 L WR 10:09:38
24.00 S TR 10:10:15
24.30 S X TR 10:11:00
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