Human and ABS

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Human and ABS

Human and ABS
absolution

Does an anti-lock braking system free the motorcyclist from all mistakes when braking, or can he solve the problems himself just as well? A comprehensive analysis.

Waldemar Schwarz

04/24/2003

The top test of the Yamaha FJR 1300 with ABS (MOTORRAD 6/2003) drove them to the barricades, the ultimate late and mega brakes and cemented their prejudices. A lively discussion about the supposedly low deceleration of 8.4 m / s² arose in the MOTORRAD online forum. Presumably because, under ideal conditions, test professionals achieve values ​​of around ten m / s² in the physical limit range, depending on the type of motorcycle. Volker Deutschmann even suspected a technical mega-flop – the, oh pity, one FJR 1300 A had ordered “blind” without a test drive. His only hope: that it might not have been the ABS itself, but the tires, the low outside temperatures or the full moon. Bernd J. comments: »I can’t imagine that Yamaha really made such a crap (…) The values ​​with ABS are exactly those that every normal brakeman can manage. ”

The latter statement is – rightly – relativized in other contributions. »Despite all the justified criticism, the braking distance is still shorter than with normal Otto drivers without ABS. Or it is already lying on the brush thanks to the over-braked front wheel. It would be interesting how different the deceleration with and without ABS is not only in the professional brakes, but also in the normal range. «Just the question that MOTORRAD now wants to finally clarify, not least to dispel questionable wisdom once and for all.

The MOTORRAD ACTION TEAM had already done important preparatory work as part of the “Motorcyclist of the Year 2002” event. In the preliminary rounds of the competition, several hundred test subjects in the braking discipline have to come to a standstill from an initial speed of around 70 km / h within a very short time. A measuring device precisely records the course of the delay and its amount. From this lavish fund, MOTORRAD was able to get a comprehensive picture.

As an example, the results of two mixed groups are analyzed, which are good for a tangible surprise: The average deceleration of 19 drivers in the first group is 6.2 m / s², a value that is quite decent in itself. However, given that the campaign appeals to ambitious motorcyclists who rate their driving skills as quite high, this value appears at best average. And it is also far from the level that the FJR 1300 with ABS has. Also noteworthy: The sports rider faction with the Yamaha R1, Honda Fireblade and Co. turned out by no means to be the superior brake species, but with an average of 6.1 m / s² even slightly worse than the rest of the motorcycle world. The absolute front runner is R 1150 GS rider Aaron T. He manages – thanks to ABS – an average deceleration of 7.9 m / s², but without fully exploiting the potential of the anti-lock braking system.

The second group of 26 drivers in the preliminary round literally slows down the first with an average deceleration of 6.8 m / s². But the analysis quickly clears up the difference. No less than six BMW boxer and F 650 GS riders with ABS drive the group’s cut up. With delays of 7.2 to 8.1 m / s², they are well above their competitors. Only a lonely Yamaha TDM rider can compete in the top group of ABS brakes with 8.1 m / s².

If you look at the course of the deceleration, the measurements clearly show that even motorcyclists with above-average experience do not even come close to utilizing the potential of their brakes because they too make serious mistakes. If the normal driver uses the capabilities of his stoppers far less than 50 percent in an emergency, experienced two-wheelers also find it difficult to decelerate and lose time and thus valuable meters. The reason: The speedometer provides information about the speed; when decelerating, the pilot has to rely solely on his feelings. And that is often deceptive. Individual test persons achieve values ​​of up to 10.0 m / s² in the course of their braking, but their hesitant brake pressure build-up nullifies a good overall deceleration. More than half of the pilots start the braking process with extremely low braking pressure and increase it continuously until the end of the braking process. An instinctive behavior that is understandable for fear of treacherous overbraking, but already wastes a lot of distance at the beginning of the braking.

Only an ABS can safely build up the brake pressure quickly. A fact that is proven by the largely good results achieved by drivers with anti-lock braking systems. Not least of all, they result from the carefree grip on the brakes, after only two to three tenths of a second they reach 80 percent of their maximum deceleration. But not only at the beginning of the deceleration valuable meters are wasted without ABS, but also in the further course. Many drivers increase the brake pressure continuously, but are afraid of their own courage well before the locking limit – and release the brake completely for a short time; to get back in again.

For most of the participants in the “Motorcyclist of the Year” campaign, several weaknesses overlap. Of a total of 45 drivers, 25 build up the brake pressure too slowly, 16 of them release the brakes completely unnecessarily far before the locking limit for fear of overbraking. Sobering conclusion: out of 45 veterans, eight deserve the rating good in the braking discipline, three of them come from the ABS camp. And that despite the fact that the drivers had the time and opportunity to practice thanks to their previous knowledge of the exercise. An opportunity that does not exist at MOTORRAD’s scheduled local appointment.

A beginner meets veteran at the MOTORRAD campaign: »Braking better with ABS« Five motorcyclists (see links below) with very different ambitions and experiences first show on the country road where the deceleration level is in real motorcycle life. All groups are represented: from the beginner Mirjam Muller to the normal drivers Daniel Alves de Jesus and Manuel Fuchs to the sports driver Oliver Noske or the hardened veteran and kilometer eater Volker Deutschmann – exactly the one who started the discussion about the ABS of the Yamaha FJR 1300 A. MOTORRAD online forum had started.

The first exercise: every driver drives a 35-kilometer circuit in the Swabian-Franconian forest, which has everything to offer the motorcyclist’s heart desires, from narrow, confusing bends to ultra-fast, far manageable alternating curves embedded in mountains and valleys. Each pilot has to complete the course without any knowledge of the route and without driving in front, just like on the long-distance tour in real life. You can choose from a wide variety of ABS motorcycles, depending on your personal taste. The range extends from the BMW F 650 GS to the sporty tourer Honda VFR and Ducati ST 4S up to the Powertourer Yamaha FJR 1300 A. While beginner Mirjam prefers the BMW F 650, Daniel and Manuel use the VFR, Ducati 998 driver Oliver, of course, use the Ducati ST 4S and FJR owner Volker, how could it be otherwise Yamaha. The machines are equipped with data recording, which precisely records the speed profile and the deceleration with every turn.

The result: the average delays of all test subjects are between two to three m / s². Mind you, it is not about emergency braking to a standstill. Even with the top values, the middle field is close together with 4.2 to 4.4 m / s². Volker comes out as a proven top brakeman. Its delays tend to be higher. It even decelerates once at 6.4 m / s². When asked about the reason, he immediately provides the explanation: “I wanted to try out whether the ABS regulates.” To do this, however, he would have to activate the stoppers much more violently.

This opportunity is offered to the candidates a short time later. From the Swabian-Franconian forest there is a direct route to the Baden Motodrom in Hockenheim. On closed-off terrain, every driver can not only approach their own limits, but – thanks to ABS – also safely approach the limits of physics. The task: From an initial speed of 100 km / h, he should complete an emergency stop at his personal limit – without a net or double bottom of the anti-lock braking system. The drivers do not know whether the ABS is activated or not. Again, a measuring device records every delay, additional distance and speed measurements underpin the individual results.

And they turn out to be very different: the bandwidth ranges between 5.5 and 7.0 m / s² and is therefore exactly in the range that the “Motorcyclist of the Year” already specified. Again Volker falls out of the ordinary and mercilessly slows down the others. At the beginning it needs time to build up a high deceleration, but then increases to the limit of the FJR without ABS of 9.5 m / s². If he hadn’t dropped so many meters at the beginning of the braking, he would have achieved an absolutely top result. But also a respectable 7.9 m / s² on average is impressive. Nevertheless, he clearly misses the maximum of the FJR with ABS.

The next rule is: Practice makes perfect. Now the five should push their own limits, trusting the ABS, and then gain experience with the different systems. After numerous braking operations with the BMW, Mirjam climbs in spheres of over eight m / s² and reports that her manual strength is insufficient for even greater decelerations. However, it is more likely to be a psychological barrier. Daniel almost completely exploits the potential of the VFR just below the control limit. The same goes for Manuel. Oliver increases his confidence in the electronic helpers up to ten m / s², an area in which the Ducati slowly begins to lift the rear wheel, but does not yet regulate it. Only Volker outwits the ABS of the FJR with individual braking operations by means of a controlled build-up of brake pressure and thus manages up to 9.5 m / s². To save the honor of the others, it should be mentioned that the veteran has already tested various ABS systems in the past. With regulation, it levels off at the Yamaha-typical 8.5 m / s².

After the experiences with the three other motorcycle models, all five drivers come to the same conclusion when assessing the anti-lock braking systems: The ABS of the VFR is the first choice among the systems tested. It does not pose any serious problems for any driver. Even the critical Volker Deutschmann, like the other participants, agrees with the realization that ABS is an enormous gain for safety. The potential of an anti-lock braking system is vastly higher than that of any normal driver. So high that they often cannot take advantage of it even after braking a lot.

After all, four of the five candidates achieved delays in the evening that they could only dream of at the beginning of the test day. The dimensions, the knowledge of what is feasible, have shifted enormously upwards. However, only after intensive practice. But ABS can do a lot more. Namely, taking into account the imponderables of everyday life such as suddenly appearing obstacles, wet roads or even slippery bitumen patches in the braking zone. As MOTORRAD has already determined in numerous tests, such exercises can only be mastered with ABS and would have taken another test day to complete.

In contrast to absolution in the Middle Ages, which pretended the indulgence of sins at face value, today every ABS offers a tangible safety plus for 500 to 1000 euros, which in an emergency quickly recovers the investment, not to mention health. The test clearly demonstrated that. And by the way, Volker calmed down. He will now swap his old Yamaha FJR 1300 for the new one. Because their anti-lock braking system is by no means a mega-flop. But one requirement remains: “I expect Yamaha to refine the ABS.”

Case study: middle class – Manuel Fuchs, 25, linguist

The budding text editor of the MOTORRAD sister magazine PS has over 20,000 kilometers of driving experience. The assessment of his driving ability: no longer a beginner, far from being an expert. He thinks ABS makes sense for big buzzers, but for athletes it is rather counterproductive. The technology must ?? in his opinion ?? still to mature. The practical test shows that it is on the move quickly: on the country road, it decelerated comparatively well at 3.0 to 4.4 m / s². On his first attempt at Hockenheim (see diagram), however, Manuel needs more than a second to build up the brake pressure, also readjusts strongly and releases the brake well before the vehicle comes to a standstill. The result: Despite peak values ​​of just over 9.0 m / s², it only achieved an average deceleration of 6.2 m / s². In the exercises that follow, he fully exploits the potential of the VFR-ABS, his first choice in the test, with values ​​of around 9.0 m / s² only after a lot of braking.

Case study: Beginner – Mirjam Muller, 26, tourism assistant

The ACTION-TEAM employee did not get her driver’s license until the end of 2001, and has driven 4000 kilometers since then. At the beginning of the test, the newcomer chooses the BMW F 650 GS because the single-cylinder suggests uncomplicated driving behavior. While driving on country roads, Mirjam has a smooth and smooth driving style and decelerates with a maximum of 3.0 m / s². On a closed route, it increases the brake pressure relatively quickly on the first attempt, but then remains at a relatively low level with constant readjustment. This results in an average deceleration of 5.5 m / s². Mirjam struggles with the too high hand strength of the BMW brakes and even after more than a dozen brake applications only achieves an average value of 8.0 m / s². It gets along better with the more spontaneous ABS of the Honda VFR, which is also due to the dual-CBS composite braking system. Makes friends with the Sporttourer straight away and immediately achieves an average of 9.1 m / s², which is almost the maximum of the Honda.

Case study: “medium to good” – Daniel Alves de Jesus, 24, a student

The current intern at MOTORRAD has more than 15,000 kilometers of driving experience and thinks ABS makes sense even before the test. Daniel does not currently own a motorcycle, so he is not in practice. Nevertheless, he takes it easy on the country road lap, decelerates the VFR in the range from 2.0 to 3.0 m / s² with a single peak value of 4.2 and thus confirms the assessment of his driving ability “medium to good” Daniel needs an extremely long time with the first braking with the Honda VFR until he reaches the maximum of 9.0 m / s². As a result, the average deceleration levels out at 6.9 m / s². In the further attempts, Daniel confirms his assessment of ABS: the more you practice, the better it works. It increases continuously from braking to braking up to 9.0 m / s², but remains just below the control limit of the ABS of the Honda VFR. A very good figure. His conclusion: ABS gives you a totally safe feeling, and he feels most comfortable on the Honda.

Case study: veteran – Volker Deutschmann, 40, entrepreneur

Volker basically wants ABS for every motorcycle; with almost 300,000 kilometers, he has an overwhelming driving experience. This is already reflected on the country road with values ​​of 3.0 to 4.7 m / s². In Hockenheim, too, the former R1 and current FJR 1300 rider confirms his solid self-assessment: He is touristy, brisk and sporty and increases towards the end of his first braking to 9.5 m / s², the maximum of the Yamaha FJR, what earned him the nickname “Volk the Brake”. With a faster build-up of brake pressure, Volker would have achieved absolute top values, so it remains at a good, but not sensational, 7.9 m / s². Then he outsmarted the ABS of the FJR with sensitive dosing and reached maximum values ​​of 9.4 m / s². The veteran also exhausts the ABS of the Ducati ST 4S, which almost ends in a rollover. On the other hand, he considers the Honda’s ABS to be “foolproof and really great,” and revises his initial aversion to composite braking systems.

Case study: “sporty recreational rider” – Oliver Noske, 23, computer scientist

Sporty recreational driver with 60,000 kilometers of driving experience, that’s Oliver’s self-assessment. He thinks ABS makes sense if it can be switched off, currently drives a Ducati 998 and, unsurprisingly, chooses the ST 4S first. On the country road it decelerates comparatively strongly with 3.5 to 4.4 m / s². In Hockenheim, Oliver impresses with the first braking through rapid brake pressure build-up of three tenths of a second, but only achieves a maximum of around 7.3 m / s², releases the brake long before the vehicle comes to a standstill and thus wastes unnecessary braking distance. Result: an average of 5.8 m / s². After braking several times with the Ducati, it increases to 10.0 m / s² and thus just keeps the rear wheel on the ground. With the VFR, which the convinced Ducatisto only drives after much persuasion, he immediately brakes into the control range ?? and is immediately enthusiastic about its braking system: “My 998 with the VFR-ABS would be the ideal combination,” is his credo after the test.

Summary: BMW ABS

The ABS of the F 650 GS is extremely functional and problem-free. It combines high deceleration, driving stability in the control range and rollover safety. Only newcomer Mirjam Muller complained about the high level of hand strength. This is low in the box models with ABS thanks to the brake booster. However, their anti-lock braking system does not work quite as easily in some situations. The most recently tested R 1150 GS and S apparently recognize the tendency to roll over when braking hard and react by opening the brake on the front wheel. Even under unfavorable conditions such as an uneven road surface or when shifting down during braking, the ABS occasionally releases the front brake for a longer than average time, so that the braking distance is significantly longer.

BMW press spokesman Jurgen Stoffregen comments: “The software for recognizing a lifting rear wheel has been in series since the R 1100 RT. This is an indirect measurement method that can determine lift-off from the rear brake pressure and the speed profile of the rear wheel. Only the trigger threshold from which the function is enabled is applied as a vehicle-specific parameter. Otherwise everything is the same. The influences of undulating roadways are known. We don’t know the connection with downshifting. As we understand it, the rear wheel then stamps, which can lead to a loss of braking distance. The deceleration portion of the rear wheel is very low and actually negligible during full braking because of the dynamic shifting of the wheel load.”

Summary: Ducati ST 4S

In the Ducati ST 4S, the anti-lock braking system does not intervene until extremely late when braking. If the driver does not release the brake in an emergency on roads with good friction values, the motorcycle can roll over. This behavior led the test candidates to extreme reluctance to deal with the Ducati.

Ducati press spokesman Kuttruf comments: »The interpretation and thus the behavior in practice is intentional. The sporty ABS deliberately only regulates under adverse conditions such as in the wet. Even professionals cannot use ABS on dry slopes. So there can be no really talk of a problem. More of a success for the sports drivers. You are not restricted in the dry and enjoy more security in difficult conditions. The ABS is explained to the customer in the same way. With this knowledge, the rollover should also not occur and at least not be more frequent than with non-ABS drivers. ”

An argument that takes itself ad absurdum. Because on sports motorcycles with extremely adhesive tires, the rear wheel usually lifts off the road before the front wheel locks. In addition to preventing the wheels from locking, a “sport ABS” must also limit the deceleration to the value at which the rollover threatens. This is the only way the driver can ?? without thinking ?? combine rapid brake pressure build-up with maximum deceleration.

Ultimately, it doesn’t matter whether the rider falls because of a blocked front wheel or a motorcycle overturning. Both are equally fatal and therefore unacceptable. In order to meet the requirement of sport ABS, Ducati should make improvements as soon as possible.

Summary: Honda VFR

The ABS of the Honda VFR convinced in the test. All participants, from beginners to veterans, felt most comfortable with the VFR system, partly because the technicians took the risk of rollover into account and limited the maximum deceleration to 9.3 m / s². Even the sports drivers want this system. The manufacturer does not seem averse to this topic, but sets other priorities.

Klaus Bescher, Product Planning Manager at Honda Motor Europe North: “In our opinion, the VFR is the sportiest Japanese motorcycle with an anti-lock braking system. The majority of German customers opt for the version with CBS and ABS. However, the VFR is also in a price segment in which the Honda drivers are willing to pay the extra charge for the ABS. We take a more critical view of this in the case of significantly cheaper models, such as a Honda Hornet 600. So far, we have already equipped 14 models with CBS or ABS and will expand the range in the future in a market-oriented manner. The topic of super sports cars with ABS is not our top priority, as we see further development potential in conventional braking systems for this segment.”

The success of the inexpensive, EUR 500 expensive ABS in the BMW F 650 GS contradicts Honda’s assessment. No less than 98 percent of customers order the F 650 GS, which costs just as much as a 600 Hornet, with the safety feature. The buyers have rewarded BMW’s courage, which should give the Honda strategists food for thought.

Summary: Yamaha FJR 1300 A

The FJR 1300 A achieves deceleration values ​​averaging 8.5 m / s² in the control range and thus worse results than comparable models. Yamaha GTS 1000 A and FJ 1200 A lagged at this level a decade ago. MOTORCYCLE measurements show that the poor control quality with strong and long deceleration drops prevents a better result. This also shows the unusually large discrepancy to the FJR without ABS, which still holds the rear wheel on the ground even at 9.5 m / s².

Yamaha press spokesman Karlheinz Vetter comments: “We are of the opinion that the main task of an ABS is to enable the driver to achieve safe emergency braking in as many conceivable driving situations as possible. The realization of a minimal braking distance was not given the highest priority. A minimum braking distance does not always represent the optimum for the driver, as there can be a risk of a rollover in the limit area. This was also a complaint in MOTORRAD in earlier tests of ABS systems from other manufacturers. With the FJR, you deliberately make small compromises in terms of maximum braking deceleration in order to achieve a safe emergency stop under all circumstances. We should also take into account that the system is designed for drivers whose driving skills are within normal limits and not for professionals who can use the system to achieve the last centimeter of braking distance.”

MOTORRAD has a consolation ready. The switch to brake pads with a significantly higher coefficient of friction compared to the series pad increased the deceleration with ABS by 0.5 to a smooth 9 m / s². Regardless, Yamaha should urgently revise its software.

Comment from MOTORRAD test editor Matthias Schroter – ABS? A must. Especially for super athletes

The success of BMW motorcycles is based in large part on the fact that the entire range of models can be equipped with ABS. The overwhelming majority of customers order ABS as an extra ?? or even gets it as standard. The Bavarians have been dealing with these security features for years and are aggressively marketing them. It is therefore all the more surprising that other manufacturers are rather hesitant about ABS. The reasons can be speculated, Honda impressively proves with the VFR how well a Japanese ABS can work in conjunction with an integral brake. All five test participants achieve excellent deceleration values ​​with the VFR, all feel right at home when braking at their physical limit, regardless of whether they are beginners or experienced.

Some from the supersport camp also revised their opinion on ABS after this test day. It didn’t hurt at all, this self-awareness. Unfortunately, the stubborn opinion still prevails in the sports group that ABS is something for the Tourer and Gore-Tex group, but not for real athletes. Just as if ABS were doing slow. What a mistake. I speak from painful experience. Last year two of my friends had a serious accident. Twice the classic number with the tractor and the dirt road. Two fatal accidents: One rammed the trailer with an Italo super sports car and will have to deal with the consequences of the injuries for a long time. For the other it was fatal. He rolled over while braking and broke his neck.

Accidents, I know, a taboo. Is hushed up, sometimes in the truest sense of the word. For me, motorcycling is the fascinating hobby in the world. There are risks involved, I am aware of that. Any form of locomotion can be fatal. Already clear. But deliberately doing without ABS or not offering it for super athletes is negligent. Just like Ducati’s attempt to explain the so-called “Sport ABS”, which is supposed to meet the needs of customers exactly. If even test professionals find it difficult to brake to the limit, how should normal people get it dealt with? Thank you for trying, Ducati, but the system is only fully developed when there is no risk of rollover. That would be a real sports ABS. None of our participants wanted to exhaust the system after Volker’s near-somersault, because their asses went up in good German. I am convinced that as soon as Rossi and Co. won even a tenth per lap on the racetrack with ABS, all super athletes without ABS would be museum pieces that are not for sale within a short time.

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