More safety on the road? Using the front brake with confidence even in slippery conditions? Lofty goals, no question. However, as impressed as we were by the potential of the first Trail ABS from 2022 - To really inspire experienced bikers, the last bit of performance was missing with so much safety. After all, braking distances with ABS should be shorter, not longer, and new brakes with ABS should be better, not worse.
It is now clear that performance alone was simply not the aim of this first ABS system for e-bikes. Because together with the new Performance Line CX motor (tested here) Bosch is also presenting a new ABS product line. The ABS Pro has instead of the familiar "Allroad" and "Trail" modes the promising "Trail Pro" and "Race" settings. Instead of modified trekking brakes with long levers, sporty mountain bike stoppers such as Maguras MT7 or the successful DH-R Evo from TRP for use. World Championship and World Cup victories, including those of Nathalie Schneitter and the Miranda Factory Racing Team in the E-EDR, served as proof of concept. The exciting question: Does the racing ABS also bring advantages to "normal" bikers?
Bosch E-Bike ABS Pro: The overview
- Controls only on the front wheel (single-channel system)
- Riding modes: Trail Pro and Race
- Can be switched on and off
- No curve detection
- Regulates from a speed of 6 km/h
- Weight of control unit: 227 grams (manufacturer's specification)
- Only available in new bikes, no retrofit option
- Only available for e-bikes
Familiar technology, new algorithm: how Bosch E-Bike ABS works
Technically speaking, the new E-Bike-ABS Pro works in a very similar way like the well-known Trail ABS. With two perforated discs on the front and rear brakes, the ABS monitors the change in speed when braking. The control system itself rides piggyback on the fork, and the additional weight of the ABS system is just over 200 grams. When the ABS intervenes, it releases some oil from the brake line into the small expansion tank, thus reducing the brake pressure. The Bosch ABS draws the necessary computing power directly from the drive system, which is why the ABS only works with newer-generation Bosch e-bikes (Smart System).
The key difference between Bosch Trail ABS and the new ABS Pro lies in the algorithm. The classic e-bike ABS, which will of course continue to exist, regulates rather conservatively. It intervenes early to nip loss of control due to over-braking or a slipping front wheel in the bud. Even in the sportier trail mode, the rear wheel remains close to the ground even during hard braking.
The Bosch ABS Pro takes a different approach here. In the new "Trail Pro" mode, the rear wheel lift-off control remains active. However, the ABS Pro also allows significantly more slip here and thus enables shorter braking distances. In "Race" mode, the rear wheel lift-off control is completely deactivated. The ABS only intervenes to prevent an excessively locked front wheel. This means that the ABS Pro regulates significantly less than the more conservative Trail version. Instead of special brakes with increased oil volume such as Magura's MTC or the Gustav Pro, "normal" mountain bike brakes can also be used with the ABS Pro. However, due to the different brake hardware, the modes are not transferable. "Trail Pro" and "Race" are only available with the ABS Pro, "Trail" and "Allroad" only with the classic e-bike ABS.
Braking like the world champions? The Bosch ABS Pro in a practical test
Anyone who explicitly puts the new Bosch ABS to the test will be impressed. The system masters gimmicks such as fully applying the front brake in a jump and still landing safely, or emergency braking with rapid changes from grippy to slippery surfaces with flying colours. At the launch event for the new engine, the ABS even had to prove itself with an emergency braking manoeuvre with rolling gravel on a smooth metal plate. Even for experienced riders, these are difficult conditions, but it was no problem for the ABS. However, the first Trail ABS was also impressively good on rapidly changing surfaces. Bosch ABS Pro is even at a slight disadvantage here, as the brake lever falls through more clearly to the handlebars during explicitly provoked control processes due to the brakes with normal oil volume.
The more exciting question: What about the sheer braking power and riding on the trail? After all, steel plates with rolling gravel are rarely found here, which is precisely why the ABS is inconspicuous and pleasant. On unfamiliar routes, even experienced testers found the more conservative "Trail Pro" mode to be unobtrusive. The system does regulate from time to time, but the rider hardly notices it. Rear wheel offset works well even with the lift-off control switched on in Trail Pro mode. Not a big surprise, After all, it already worked with the trail mode of the classic e-bike ABS.
Increased level of difficulty: full braking and bike park use with ABS
So we increase the level of difficulty. Full braking on tarmac and gravel is the next task. At the same initial speed, the bike stops significantly faster with the system switched off and in "Race" mode than in "Trail Pro" mode, assuming an experienced rider. As the rear wheel gets a lot of air under the tyres, the lift-off control in "Trail Pro" mode alone is probably the decisive reason. We can hardly see any differences between "Race" and the deactivated system. The only difference is that "Race" absorbs sudden skids or braking errors, whereas with the system switched off, you would probably fall on your face if you made a mistake.
As the lift-off control is not active in "Race" mode, you have to be careful not to fly over the handlebars. A centre position would be desirable for the future. With more freedom for the rear wheel than in "Trail Pro" mode, you could brake even harder without having to fear a rollover like in "Race" mode.
Last but not least, we venture onto one of our standard test tracks: The "Fichtenschreck" downhill in the Oberammergau bike park. Can the Bosch ABS Pro still hold its own when you're chasing downhill at speed on familiar courses? The verdict on the "Trail Pro" mode is clear. In this particular scenario, "Trail Pro" simply delivers too little braking power and intervenes too clearly for our liking. "Race", on the other hand, delivered braking power at a very high level. But here too, the logger recorded an astonishing number of control processes without us being aware of any major riding errors or braking errors. Does the ABS still regulate too much even in "Race" mode? Or do you overtighten the grip in such situations more than you realise when riding?
The fact is that one of the test riders found ABS to be a clear added value, while the other found the intervention of the Race ABS too patronising, at least in this extreme scenario. Almost everywhere else, however, ABS Pro should also make really demanding professionals happy. This is probably especially true for unknown and particularly slippery conditions. Whether and under what conditions does ABS really make you faster? We want to find out in further tests.
BIKE summary of the Bosch ABS Pro
We were already impressed by the first Trail ABS from 2022. With the ABS Pro, Bosch has significantly improved on the main point of criticism: ABS Pro now delivers braking power en masse, making even very demanding riders happy. In addition, the system also works with normal MTB brakes with sporty ergonomics and still reliably intercepts braking errors. A clear recommendation! - Adrian Kaether, Editor Test & Technology
Faster thanks to ABS? Interview with Bosch CEO Claus Fleischer
BIKE: What is the aim of the ABS Pro? Is it still about safety?
CLAUS FLEISCHER: The aim is to achieve the optimum balance between riding stability and maximum braking performance on the trail: with ABS Pro, it is possible to brake later and harder, allowing you to ride faster for longer and concentrate on your line.
How do the "Trail Pro" and "Race" ABS modes differ from the previous Trail mode?
ABS Pro is ideal for anyone who likes to ride fast and sporty. The "Trail Pro" mode enables more efficient and stable braking and can also prevent excessive lifting of the rear wheel. "Race" is the mode for E-MTB pros. Here, the rear wheel lift control is deactivated - and the focus is even more on maximum trail performance.
You also market ABS Pro with professional athletes. In which situations does the ABS Pro actually make you faster?
In competition use, athletes have already achieved enduro victories and world championship titles with it. With the ABS Pro, they can brake later and harder while focussing on the optimum riding line for longer; seconds are gained.
Adrian Kaether
Editor
