Dakar: Repsol - Secrets for the journey

Dakar 2005: The secrets for a journey through the desert When it is about covering almost 9,000 km on paths, tracks, crossing villages, deserts and dunes, the navigation systems of the cars, motorbikes and trucks taking part in the Dakar play...

Dakar 2005: The secrets for a journey through the desert

When it is about covering almost 9,000 km on paths, tracks, crossing villages, deserts and dunes, the navigation systems of the cars, motorbikes and trucks taking part in the Dakar play an essential role.

Marc Coma explained us every little detail of the features and function of the navigation devices of his KTM Repsol 660 Rally: the tripmaster, the repeater, the road book and the GPS, the four main tools he will be using to position himself and find his way to Dakar. Strategically located in the front end of his bike, the four systems are exactly positioned with the road book in the centre, the repeater and the tripmaster in the upper part and the GPS just below to be within the rider's reach at any time.

No system is dispensable, but the road book would be the basic tool, which is complemented by the others. It is provided by the Organisation and it is made up of a summary of informative indications of what the riders are going to find along the way. The page number, number and name of the stage, as well as the maximum time to cover it make up the heading. Below there are several vignettes structured in three columns. The first column has the corresponding kilometre points, the second shows the way to follow (diversions, crossings, villages...) and the references (rivers, kaerns, oasis, trees...), and the third column has comments on the said point. This last column includes warnings, GPS points, refuelling points, if the track goes up or down, etc. There are three warning levels indicated by means of one, two or three exclamation marks. The first level is only important for trucks; motorbikes have to brake, locate the danger and then pass it in the case of second level marks; and the third level warnings can only be solved with the first gear on, because they are usually technically highly complicated points. The CPs or checkpoints are indicated as well. Riders and drivers are forced to pass these checkpoints to get their time cards stamped or else they would get a five-hour penalty.

To be able to fully open the throttle, focussed on riding and not having to be constantly checking the road book, riders highlight the most important indications with colour markers. Thus they can know what to do at any time with only a quick glance on the book. Every rider has his own technique and every colour has a special meaning. All Repsol riders, being Arcarons' pupils, work with three colours: blue, green and red. The use of the green colour is free, but it means that those indications do not need much attention. Blue, however, means a very important change of direction that may lead to a mistake that may be very difficult to correct later. The most important indications are marked in red and they represent dangers, such as a hole in a river, a village where the radar limits the speed to 50 Km/h, a tight or stony section, or a downward trial-like section, among others. In these cases and considering the speed of arrival, if the riders do not anticipate the situation, because they cannot see it or because once they get there, they cannot avoid it, they might suffer serious consequences.

Since the Dakar organisation draws up the road book in September and from then to January the terrain and rivers may have changed due to sand storms and rain, there are the so-called "gravel cars". These are marshal teams who travel one or two days ahead of the race, checking the road book, to inform participants about the changes before every stage is run. The road book is the same for cars, trucks and motorbikes, but whilst the road book for cars and truck is like a booklet, the motorbike road book is rolled like a papyrus inside a special support. By means of an electrical device, operated by a lever located on the left handlebar, the rider moves it forward during the stage.

The tripmaster is a kilometre-counting device that always has to match with the kilometres indicated in the road book. The problem is that the road book is drawn up with a car that is able to keep the straight line much easier than a motorbike that has to move sideways. Thus the distances are sometimes longer or sometimes shorter and it becomes really difficult to match numbers. To correct it and to help the rider to keep the reference points, there are two buttons on the left handlebar, allowing the rider to add or subtract kilometres from the counter and correct possible deviations. Without the tripmaster, the rider would be riding like blind and therefore, there is a second tripmaster below the road book that usually shows the speed, but would be able to indicate the covered kilometres in case of a failure of the main tripmaster.

To verify that the right path is being followed, there is another navigation tool called repeater, a digital compass via satellite, marking the compass degrees. North are cero degrees, South 180º, East 90º and West 270º. These degrees, as in the case of the tripmaster, must match the degrees indicated in the road book at the corresponding kilometre point. The repeater plays its most important role when riding through the desert because there are not many additional references. In these cases, the riders have to follow the degrees on the compass to follow the right course and keep it during the kilometres indicated in the road book.

Along the route of each stage, there are certain points, which riders and drivers have to pass compulsorily, i.e. the GPS points. This year, most of the Dakar stages are mainly navigation stages and therefore only the GPS points of the checkpoints and the arrival are marked. The organisation's intention is to restrict these points as much as possible to let the skills of drivers and riders following the road book predominate. In order to locate and follow these points, drivers use the GPS, which carries out two main functions: it acts as a repeater and it does the usual GPS navigation. The GPS points are limited by the organisation that provides participants with the codes of every stage; this is the only thing drivers and riders can enter. The GPS shows, by means of an arrow, the straight way from one point to the other, but there might be a mountain in-between hindering the straight way, and therefore the road book becomes essential. There might also be the case of a rider slightly changing his path going up and down a dune. If this slight change is kept for several kilometres it may mean an irreparable course change. As a repeater, the GPS is extremely important when riding off-track, where there are fewer references, everything becomes more theoretical and it's easier to ride on a straight line. In addition to the arrow and the theoretical compass degrees, it also indicates the degree correction as the path is changed and the distance to the next GPS point. All in all, it is an additional tool to confirm that you're following the right path.

But, what happens if one of the systems fails? Depending on the failure, you may be able to continue and reach the bivouac, where the mechanics would fix it, or you'd have to stop and repair it yourself. The most frequent failures are the sensors or the tripmaster cables on the tyre torn off by a stone, or the electric engine of the road book device burnt. In the first of these cases, continuing would be very complicated, because it would be like riding blindly. If you have a lot of experience you may try to move on, but the usual reaction is to stop and fix it or wait for somebody else to follow. The second case is less serious because the road book support has a little side-lever allowing to move pages manually, although the rider would then need to ride with one hand. With no doubt, the worst failure, but also the less frequent is a GPS failure. The only possible solution is to wait for somebody to follow, but it is also important not to let the other know the reason for it. It's a thing about team interests and tactics that can make you loose the race. However above all of this, meaning positioning oneself, orientation and choosing the right path, you have to be constantly checking the motorbike's fuel level...

Black gold in the desert

Covering marathon stages with almost 600 timed kilometres, such as the ones to be run in Mali and Mauritania, needs a detailed study of the fuel needs. The KTM Repsol 660 Rally has four fuel tanks, two in the front and two in the rear with a capacity of 12 litres for the front tanks and 11 litres for the rear ones. These four tanks are interconnected but there is the possibility to separate the front ones to decide which one to use, turning a key located on the left footrest. Being able to adjust where we want to get the fuel from is a fundamental aspect as regards the weight transfer of the bike, because it may mean a change of the bike's behaviour. While the bike weights 180 kg without fuel, the figure moves up to 215 kg with the tanks filled. As a general rule you always try to empty the rear tanks first because the tyre suffers a lot with the weight in the rear. In addition, if you carry weight on your back when jumping, the bike has much more inertia and you have the risk to land destabilised, a situation that might involve a crash. The fact of using the fuel of the rear tank or the front tank depends also on the kind of surface. The rear tyre doesn't suffer on dunes because there are no stones and the surface is softer; in this case, if the bike is too heavy in the front, it tends to sink and driving becomes more tiring for the rider.

Each of the stages is carefully studied the day before. That is when the strategy regarding fuel consumption and refuelling is prepared. There is a person in charge of consumptions in the team, who is the one who decides how much fuel to take from the start and how much to refuel. The organisation demands autonomy of 320 kilometres and therefore there are some days where you start with full tanks and other with less filled tanks, depending on the stage, and the number and distance of the refuelling points. To the minimum calculated fuel quantity you usually add enough fuel to cover 100 additional kilometres in case of an incidence, as a safety margin. It is compulsory to stop at the refuelling points where riders and drivers are neutralised between 10 and 15 minutes, the time needed to refuel, check the bike, eat and drink something, tidy oneself up or fill water into the "camel bag", a little backpack they use to drink during the stage, with a capacity of one or two litres. When restarting, it is very important that the rider is conscious about the fact that the behaviour of the bike will be different to that at the time he reached the refuelling point; if he weren't, he would risk an accident.

Under normal race conditions, the KTM 660 Rally uses some 10 litres on 100 kilometres. The largest consumption is registered on sandy, soft, difficult surfaces, where it may reach 15 litres on 100 kilometres. The bike consumes less during liaisons because the pace is slower, you ride on harder tracks and have a constant speed. Despite working with safety margins, the motorbike may run out of fuel. In this case there would be nothing else to do than to wait for a team-mate or another rider to stop and ask him for a bit of fuel. It is rather unlikely that those riding in the lead will stop, but once the top 15 or 20 have passed, the others usually do. It is a part of the Dakar's solidarity, where people want to race but also to experience the adventure.

But if fuel is essential for the bike, water is obviously essential for the rider. With this in mind, the organisation forces the riders to equip their bikes with two water tanks in the lower part of the front end, with a capacity of one litre each. This is a safety measure that together with the "camel bag", i.e. the backpack carried by the riders with a capacity of two additional litres, can avoid dehydration of the rider in case of a breakdown and having to wait one or two days for the arrival of the pick-up truck.

In addition to the physical roughness, the Dakar also and always requires a high level of concentration and adaptation to ride, as well as dealing with all the dangers of the most famous rally of the world. Navigation systems are only help, because the rider always has to put the rest, and obviously always has to remember refuelling...


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About this article
Series DAKAR
Drivers Marc Coma