Rally Clock With Rotating Bezel: Application Notes

Here are some tips and suggestions for using a rally clock with a rotating bezel in the Great Race. Historically, rotating bezels have been used for watch synchronization and elapsed time measurements. Diver’s watches popularized the use of elapsed-time rotating bezels, and in recent years, countdown bezels have gained favor. While elapsed-time measurements are desirable in various applications, many users find countdown bezels more practical and useful. Both types can be useful in road rally applications, and that is why the dual-mode count-up/countdown rotating bezel of the Rally Clocks Master Time clock is popular with rally teams.

A time-of-day clock with a dual-function countdown/count-up bezel provides much more function than a typical Great Race clock. It can answer three important questions: 

1. What time is it?
2. How much time has elapsed?
3. How much time remains?

Applications

Here are some of the more common timekeeping applications in the Great Race and how this clock can improve your performance:

• Out Time Countdown
• Tracking Speedometer Error Adjustments
• Elapsed Time Since Instruction
• Transit Timer
• Time Synchronization Hack

Out Time Countdown

The most straightforward application of the countdown bezel is keeping track of your remaining time before time-of-day restarts. If the official starting time is 8:30, and you are assigned a starting position of 17, then rotate the bezel until the red 17 mark of the bezel is aligned with the 30-minute mark on the face of the clock. The bezel now provides a countdown in minutes to your designated out time of 8:47.

Additionally, the 30-minute mark on the bezel now points to 8:17, which is the time when your route instructions for the day will be available (30 minutes before your start time).

Once you are within the final minute of your start time, you can adjust the bezel to provide a final countdown in seconds. For example, if the designated speed is 40MPH, and you know your vehicle loses 6 seconds when acceleration from 0 to 40, then rotate the bezel until the green 6 of the bezel is aligned with the 0-minute triangle on the face of the clock. Alternatively, you may prefer to think of it as rotating the bezel until its zero mark is on the 54-second mark of the clock face (6 seconds before the minute).

Tracking Speedometer Error Adjustments

If the speedometer calibration portion of the day’s first leg shows that you are 1 second early every 20 minutes, then you must determine how to compensate for that error. If you are using a Timewise 825 Speedometer, you can adjust your calibration factor so that it will cause you to run 3 seconds an hour slower (1 second every 20 minutes). However, you may not have enough time to perform this adjustment, may decide the error is too small to adjust, or may not have an adjustable speedometer. In these cases, the rotating bezel can track when you need to perform a time adjustment on the rally course.

Continuing with the preceding example, if there is a time-of-day restart at 10:00 and you are in starting position 17, then rotate the bezel until the zero mark of the bezel is aligned with 17 minutes on the clock face. At your restart time, no time speedometer adjustment is required, and this will be indicated by the clock’s minute hand being aligned with the zero mark of the bezel.

At 10:37 the clock’s minute hand will be pointing to 20 (in the green) on the bezel reminding you that you are 1 second early every 20 minutes. You can then burn that 1-second, which puts you back on time. Once you have completed your time adjustment, rotate the bezel until its zero mark aligns with 37 on the clock face. By constantly doing these corrections throughout the day, the zero mark of the bezel will always be pointing to the time of day when no speedometer error correction is required.

If you see a checkpoint coming up, you can quickly check how long it has been since your last speedometer error adjustment and compensate accordingly before arriving at the checkpoint. Once you cross the checkpoint, rotate the bezel to the current minute again indicating that you are on time for the new leg.

Additionally, remember that any speedometer error does not come into play during transits. Therefore, if you encounter a 15-minute transit, you should rotate the bezel 15 minutes forward to track your speedometer error adjustments correctly.

Elapsed Time Since Last Instruction

Many rally participants find tracking the elapsed time from a particular instruction useful. One reason is to correct for speedometer errors at lower speeds. For the Great Race, most speedometer calibration runs are performed at 50MPH, providing each team with the needed data to ensure their speedometer is accurate at 50MPH. However, speedometer error is not always linear. Each Timewise 825 Speedometer comes with a calibration report indicating its amount of error at each 5MPH increment due to variations in face plate manufacturing and mechanical tolerances. Therefore, you can use the rotating bezel to track how long you have been at a given speed to determine if any adjustment is warranted.

Transit Timer

The bezel can be used to keep track of a 10-minute transit. It can keep rough track of the minutes remaining in your transit or the exact seconds in the last minute of your transit, but not both. You must determine whether to use it to track minutes or final seconds. You can try to do both, although it may prove more confusing than helpful. Personally, I prefer to keep track of transit time with a stopwatch while aligning the clock bezel with the adjusted out time seconds (time-of-day start of transit + transit time – time loss accelerating to out speed).

Great Race rules state there is a penalty for any vehicle that leaves a lunch stop or rest stop more than 5 minutes before its specified time. Tracking the countdown to when you can have a penalty-free exit may prove to be an excellent use of your countdown bezel.

Time Synchronization Hack

The first rotating bezel was patented in 1935 and its early use on watches was primarily for second-hand synchronization. You’ve probably seen an old war movie where someone would say let’s synchronize our watches. The team leader would state the upcoming minute, countdown the seconds, and say “mark” when zero was reached. It was up to the other team members to rotate their bezels so the zero mark of the bezel aligned with wherever the second hand was when “mark” was called out.

Since the Rally Clocks Master Time clock already has a hackable second hand to align with official rally time, using the bezel as a synchronization hack would not be a wise use of this feature. It is included here primarily for its historical perspective.

Combine with an Analog Stopwatch

The time-of-day rally clock combined with an analog stopwatch having a rotating bezel, provides a pair of timing devices that will enhance and elevate your Great Race experience and performance.

Rally Clocks by Bowport manufactures and sells clocks, stopwatches, and accessories for the Great Race and other rally events.

The Master Time Rally Clock includes a unique rotating count-up/countdown bezel. It features a Seiko SKP quartz movement, hackable sweeping second hand with on/off switch, Flieger pilot-style design, 2-tier layered high-contrast 6″ dial, 7″ bezel, 2″ depth, and weighs 16 ounces. Velcro mounting is preferred for rally vehicles, although the clock also includes a tabletop stand for non-vehicle use. Four different models are available.

The Analog Stopwatch assembly includes: 1) a new (in the box) EAI 50mm, 13-jewel 2-button mechanical analog stopwatch with 60-second sweep, 1/5 second markings, 30-minute register, and a stainless steel case; 2) a custom 3-color rotating countdown bezel; 3) a custom stopwatch case; 4) and three Heuer Sebring compatible mounting plates providing multiple mounting angles and options.

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Resources and Links

• The Rally Clocks Shop is where you can purchase a 6″ Master Time Rally Clock with a dual-function countdown/up bezel and/or a 2″ (50mm) Analog Stopwatch with a countdown bezel.
• Analog Stopwatch With Countdown Bezel: Application Notes
• The Great Race
• More Great Race and Rally Articles