Market / E-Performance: After a few rumors in recent weeks and months, the cat was let out of the bag at Bosch today. The first Bosch e-bikes with ABS braking systems will be launched this year. You could contribute a lot of know-how from the motorcycle sector and work closely with the Swabian brake specialists from Magura. We had the chance to subject the system to a short test.
It was undoubtedly only a matter of time and in the past there were repeated rumors about ABS on bicycles. Today, e-bike specialist Bosch presented the first production-ready ABS braking system, which will only be available for e-bikes with a Bosch drive. First in autumn 2017 in selected bicycle fleets as a close partner, from mid-2018 also on normal series e-bikes.
Now there may certainly be some who question the need for such a system, at least in part. Was it possible without it, wasn't it? Sure, you can always raise this objection, but you also have to keep in mind that the bicycle market is currently undergoing decisive change. E-bikes are becoming more and more popular, in the city and in the country. On the one hand, this is of course a very welcome development, for the bicycle market as well as for the development of a new form of mobility.
However, the triumph of e-bikes also brings some problems. The wheels, which tend to be rather heavy, can often be accelerated quite effortlessly to 25 km/h and faster and must come to a standstill accordingly quickly in the event of emergency braking. The bicycle manufacturers have learned something new there in the past and now equip most e-bikes with powerful disc brakes. Now so much braking power needs to be used properly. Less experienced cyclists in particular have problems with this. Many people mainly use the rear wheel brake and thus only a small fraction of the available power - the braking distance is much longer. The brake on the front wheel is suspect to many: the fear of overturning or uncontrolled slipping on gravel is too great. This is exactly where Bosch wants to intervene with the new ABS braking system and also limits its ABS to use on the front wheel. According to specially commissioned studies, one in four pedelec accidents could be prevented through the widespread use of ABS.
Bosch e-bike ABS: A development advantage thanks to motorcycles
As a leading provider of motorcycle safety technology, Bosch naturally has a major development advantage over the competition, which up until now has only been limited to the bicycle market. Of course, motorcycle technology can by no means be transferred 1:1 to bicycles or e-bikes, but important know-how and invaluable experience from recent years have of course been of great help to the e-bike ABS developers at Bosch. As early as 1994, Bosch used the first anti-lock brakes on Japanese police motorcycles. Since then, research has been carried out in this area and the existing systems have been consistently further developed.
Magura's Swabian "neighbors" were an important partner in the development process of the new ABS. The brake specialist has been working with Bosch in various areas for several years now and designed the new CMe ABS brake, with which the Bosch e-bike ABS is used exclusively. This is a four-piston brake with new brake levers, which are a touch longer than the Carbotec units known from Magura's MT5 or MT7.
Bosch E-Bike ABS: control unit under the handlebars
The "brain" of the Bosch E-Bike ABS is located in a black box that is not necessarily inconspicuous in appearance and is attached under the handlebars. A status LED at the height of the stem also provides information about the proper functioning of the braking system. In terms of system integration, there is still a lot of room for improvement - Bosch knows that too and the idea for the future is definitely to integrate the ABS into the frame as well. But first you want to wait for the manufacturer's feedback and then feel your way forward step by step. That also seems quite plausible: You just have to consider how bulky e-bike batteries looked three or four years ago compared to today.
But back to the control unit: This constantly receives signals from two wheel speed sensors while driving. To ensure that these work reliably at all times, solutions that are often somewhat problematic, such as spoke magnets, are abandoned and instead two measuring discs are mounted above the brake discs, as on a motorcycle. However, these require additional space and the system is therefore not compatible with every fork and every hub.
All in all, the entire ABS – including the discs, cables and control unit – weighs around 800 grams. That may seem like a lot at first glance, but if you put it in relation to the total weight of an e-bike, it puts it into perspective again. Initially, the ABS only comes in combination with the Performance Line Cruise and Speed drives.
Bosch E-Bike ABS: Big Brother is watching you
While driving, the ABS control unit is not only supplied with data from the aforementioned speed sensors, but also collects information provided by the drive: This includes speed, cadence, power and some more. Complicated algorithms use this to calculate the driving situation: is it going steeply downhill? How much does the driver kick? What is the subsoil like? Depending on this, the ABS also adjusts the initial braking power. For example, if you roll down a hill at high speed and pull on the front brake, the system does not provide full power right from the start in order to prevent a rollover. Specifically, one would like to counteract two fall scenarios in particular:
Braking scenario 1: The front wheel threatens to lock up
If the system registers that the front wheel is about to lock up during braking and there is a risk of either slipping on slippery surfaces or rolling over when there is more grip, it automatically reduces the braking force and increases it again as soon as the wheel starts turning faster again begins. This gives you the greatest possible braking power without risking a locking front wheel.
Braking scenario 2: Imminent rollover
But wait a minute: Every cyclist knows that when driving fast and braking on the front wheel, the rear wheel often lifts off long before the front wheel locks. But there is already an algorithm in the system for this: If it is registered that the rear wheel is lifting off the ground, the braking force is also reduced.
Bosch E-Bike ABS: First riding impressions
We will only be able to test the new e-bike ABS extensively in the coming months, but of course we still wanted to do a few test laps on the course in front of the Bosch headquarters. Of course, the look isn't necessarily elegant, but we're confident that things will change in the coming years. In our opinion, the brake levers also have room for improvement, as they are a bit sharp-edged and therefore not entirely convincing from an ergonomic point of view.
With that, however, we would have fished the only two hairs out of the soup - because the function of the ABS is great. If you pull at high speed against all biker instincts that you have accumulated with great effort and with full force on the front brake, it is quite unusual; The front wheel does not lock up and threaten to slip away, nor do we have to use all our might to keep the rear wheel on the ground. If you pull both brakes at the same time, you get an extremely short braking distance and full, very controlled braking.
The fact that the pulled brake lever moves a little towards the handlebars when the ABS is active takes some getting used to. The reason for this lies in the lack of return pumping of the brake fluid. But don't worry: if the fluid level drops too far, the system switches off automatically and you regain full braking power.
Bosch e-bike ABS: prices and availability
First, the Bosch e-bike ABS will be used on bikes from selected rental and tourism partners in autumn 2017. The system will be made available to the manufacturers at the end of 2018 - so the first ABS e-bikes in series production should not be expected before the 2019 model year. Since the ABS will not be available for retrofitting, one can only speculate about prices. However, Bosch estimates that e-bikes with ABS will cost around €500 more than identically equipped bikes with conventional brakes.