Background
Unbound has become one of the largest gravel bicycling events in the world. Once riders toe the start line of this 200 mile course, they are on their own. Riders can only accept help from non-participants at two designated checkpoints along the course. If a rider calls for assistance at any time outside of one of these checkpoints, they are disqualified and not permitted to continue. Given the distances and terrain of the Flint Hills gravel roads, mechanical issues are part of the day for many riders. Heat, wind, rain and severe weather have all contributed to this event, sometimes all in the same year. Much of the appeal of this event is the challenge in working through personal and mechanical issues on the course.
Objective
Kansas City Jeep Club (KCJC) and Emporia Amateur Radio Society (EARS) work together during this event to satisfy two main objectives. We provide a dispatch center and communications infrastructure system where any participants can call (if they have cellular coverage) if they are in an emergency situation. As our services become required, we are able to roll Jeeps on course to provide assistance as needed.
In emergency situations, it is important for us to get a Jeep crew into an area immediately to manage a situation until EMT/First Responders help can arrive. We have been involved a number of Ambulance and LifeFlight rides over the years but thankfully v2022 did not have a 911 type emergency come through our dispatch center. This is unusual but welcomed.
We also worked with the non-profit group Camp Alexander. This group volunteered their time to provide non-emergency race day support to riders requesting their services. EARS/KCJC, provided transportation and extraction services for those riders who wished to leave the course. The reason for the extractions varied from dehydration and hunger to cramps or a simple lack of motivation. Riders understood that once they accepted our support, their day on the bike was over and they were disqualified.
With over 4,000 riders heading South out of Emporia, Ks into the Flint Hills prairie, the sheer volume of riders guarantees a busy day for race organizers and volunteers. Parts of this 200 mile course are not covered by consumer cellular network providers so telephone simply cannot be counted on. We learned years ago that if we wanted to insure a communication path throughout this course, we would have to build it ourselves.
Planning
In order to provide these services we must be able to communicate effectively to, and travel to nearly all points on the course and the access roads in the area. The process of creating a plan we could execute on race day began months prior to the event. This is the 6th year we have been involved in this event so we had the benefit of past experience working in our favor. We knew we were again going to put our club trailer downtown near the start/finish line. This puts net control/dispatch in constant contact with race organizers and creates an office workspace for volunteers. This trailer was built to be versatile and for this event we use all three of the operating positions. Position #1 is used for our net control radio operator. He has access to a dual band radio, a reasonable antenna and our local repeater. Position #2 is his logger and dispatcher. As requests come in, and are resolved, this position logs information into the computer database and keeps track of dispatch tickets. Position #3 was used for administrative purposes. Riders are given an emergency contact number during their orientation and that number rings into our trailer where calls are triaged and dispatched as necessary.
Communication is pointless if there is nobody to talk to. KCJC and EARS have a symbiotic relationship and we rely on each others strengths. EARS provides the communications logistics while KCJC provides a fleet of 20 amateur radio equipped Jeeps and radio operators to roam the course and provide the eyes, ears and muscle along the route. Each group relies heavily on the other and neither could meet our objectives without the other. We all work tirelessly throughout planning and race day and both groups thoroughly enjoy the relationship.
Early in the process, race organizers provided us with the course which we laid down in Google Earth. Given the nature of the task at hand, our goal was to provide better than S7 signal across the course. This year, the route went South, directly into the footprint of our local repeater. Using SPLAT! software we generated a computer generated theoretical > S7 coverage map of our 146.985 repeater over the top of our bicycle course. As the route continues South however, we expected repeater coverage to become problematic and the SPLAT! propagation maps validated our concerns. So, portable crossband ‘drop repeaters’ were planned at strategic locations along the course. Each of these drop repeaters would provide a 15(ish) mile radius UHF footprint and crossbanded VHF link back to the main repeater. By choosing our drop locations carefully, UHF coverage into previously weak spots would be solid and provide our Jeeps with nearly 100% coverage across the course. This requires our Jeep operators to monitor different frequencies as they move along the course but that is covered in our pre-race meeting. We then began looking for favorable locations to drop our portable crossband repeaters to supplement our coverage. When looking for these locations we took several considerations into account:
- Height above average terrain (HAAT)
- RF access back to our 146.985 repeater
- Serviceability
- Landowner Permission
We have been very fortunate in the willingness of landowner’s to grant permission for us to use their land. The relationship between the race and the landowners is solid and is a testament to the founders of this race and their ideals. As with so many things, the relationship made our job much easier to execute.
Whenever possible we like to put our equipment near to but not on the course. This gives us the ability to get in and service equipment without traveling on the course. This allows for quicker access times and reduces the amount of vehicle traffic on the course making for a safer environment for the participants. Thankfully to date, the only real service we have been involved in during the race has been the re-fueling of the generators.
Studying the coverage maps across the course, we determined the soft spots in our repeater coverage and began looking for satisfactory locations for our drop repeaters. Topo maps were utilized to determine high spots and then theoretical SPLAT! coverages were created. In the end we determined three additional drop locations would serve our needs well. They were located near MM 45, MM77 and MM 100. The respective coverages are shown in the links.
Implementation
Surprisingly, the hardware for our drop machines is quite simple. We generally use standard dual band Kenwood V71 radios in a cross-band configuration. Power comes from small Honda generators and Astron linear power supplies. The entire setup (sans generators) is bolted together along with fans blowing across the heatsinks and is housed in a Tupperware type container outfitted with input and output forced airflow for cooling. The mass of the power supplies provide ballast for the containers and keeps them from blowing over (or away) in the Kansas wind. The fans provide the airflow needed to keep the equipment temperature within acceptable limits. The antenna systems are Diamond X30 fed with LMR400 cable.
Due to the relative small footprint needed and our drop location HAAT, we do not need much of an antenna support structure. We use a 5 to 10 foot mast attached to a fence post as the mounting for our antennas. It always amazes us how far radio waves fly when launched off of high ground.
Observations/Gotchas
It must be noted that using a standard dual band rig in a high duty-cycle crossband application is risky and has severe limitations. We run these dual band radios in low power and we blow a significant amount of forced air across the rigs to keep them cool. We also use fans to pull filtered outside air in through the bottom of the container and a complimentary output fan at the top of the other side as an exhaust.
For this race we used and tested two smaller Lexien radios and a homebrew Arduino “controller” as the crossband system for one of our drops. While not quite as compact or easy to program as the V71, this setup offers several advantages. By using two discrete radios we cut the duty-cycle of each radio in half as well as doubling the heat sink capabilities making it possible for us to run higher power. The Lexien radios are significantly cheaper than the name brand counterparts and we can custom 3D print fan enclosures to provide substantial airflow around the heatsinks. We also are testing two QYT radios in crossband mode connected via their proprietary cable which eliminates the need for the additional Arduino controller. The results of these tests were encouraging.
We have learned that race promoters enjoy putting their riders in the most beautiful and difficult spots imaginable. We have also learned that these challenging spots are often in gullies, behind hills or along creeks. These landscapes rarely lend themselves to good RF propagation which increases the need for the drop repeater systems. Given the relative simplicity of our drop setups, things worked very well. As expected, there were locations on the course where coverage was not optimum but those areas were few and far between.
You may have noticed we discuss location in terms of the mile marker on the course. Garmin and other GPS companies make sophisticated bike computers that give all types of race day metrics back to the riders. In events like this, nearly every rider utilizes these devices. Distance ridden is common on these units and nearly every rider knows exactly how far they have ridden at any given time during a race. When calls come into our dispatch phone, the first question the rider is asked is how far into the race (in miles) they have ridden. That gives us the course mile marker and Jeeps are dispatched accordingly. Jeeps, dispatch and net control all use Avenza Maps with the course and mile markers layered on a real time map. Given the very long stretches of course without any cross-streets or houses, we have determined the mile marker method is superior to using addresses. In rare cases, riders are unaware of their location and we ask them to drop us a “Google Pin.”
Prior to the race, each rider is given a unique “bib number” plate. This plate is much like a small license plate and must be displayed on the riders bicycle. This bib number corresponds to the rider for the day and is used as the primary form of identification.
Problems
Interestingly, most problems we discover are not technical. Our biggest issue is finding riders that call for extraction and then are nowhere to be found when we arrive. Often times we learn the rider was able to fix their problem or gain the motivation needed to continue before we could arrive. This happens quite often and we are forced to continue looking for these riders until we can confirm their safety.
Long Day
This is a long race and that makes for a very long day. Our day begins at 5A with our support meeting. The official race ending time is 3A the following morning with riders occasionally coming in past the deadline. Some of our crew run in shifts but others remain throughout the 22 hour event. We were able to break down our drop repeater locations once the race moved past their locations. In one case that occurred way after dark but it did allow us to get home before sunrise.
Conclusion
For us, this is what ham radio is all about. It gives us the opportunity to put our skills and resources to use while helping others. This event is a huge deal for our small Kansas town and being involved in such a hands on way is a lot of fun. The evolving relationship between EARS and KCJC is the “secret sauce” for our combined success. Generally, the calls that come into our trailer lead to a Jeep roll, minor first aid and a simple trip back to town for a rider, which is fine with us. We much prefer those casual calls to the serious situations that come up occasionally. When those serious emergencies emerge (and they do), our team is there to provide any assistance needed for as long as is needed. The overall goal is to make the event safer for all participants and spectators.