The ongoing ABS motorcycle vs non-ABS motorcycle is a strange thing. I would wager that it is impossible today to buy a new car in the western world without ABS. It’s a standard feature on the most high end of sports cars down to family sedans and small hatchbacks. It’s only not used in motor sports like Formula 1 because it took away from the required skills of the driver and made braking too easy. Despite all of this, there is still a large percentage of brand new motorcycles that either don’t have ABS at all or as an option. So if ABS on four wheels is good, why do some consider it on two wheels to be bad?
It’s especially baffling because braking on a motorcycle is much more difficult than for a car. First of all, you have separate controls for both the front and rear brakes on a bike with a requirement to apply differing amounts of force to each – one with the right hand and one with the right foot. On a car, if you lock the front brake it’s easy to release the brake pedal and reapply pressure. On a bike, a front wheel lock like will almost always result in a crash. Ironically, a study by the Association of European Motorcycle Manufacturers (2004) showed that many riders, fearing a front brake lock didn’t apply anywhere near maximum braking force which resulted in longer stopping distances and therefore avoidable accidents.
So is it necessary to have ABS on a motorcycle? Can a skillful rider brake faster on a bike without ABS then with it? We’ve combed through a variety of published journal articles as well as motorcycle magazine testing to find out just that. And we’re also going to refute some common claims around ABS that Joe Squid likes to trot out as to why he doesn’t have ABS on his bike.
Firstly a quick summary on how ABS works from BMW who were the pioneers of making ABS standard on motorcycles:
Wheel sensors measure the rotational speed of the front and rear wheels and identify when the wheel begins to lock. The sensors pass on a measured impulse to a processor, which activates a pressure modulator in the hydraulic brake circuit of the front or rear wheel. The activated pressure modulator reduces brake pressure in a fraction of a second and then increases it once more. This means that the ABS applies just the right amount of brake pressure within the ABS range to the appropriate wheel as required to keep the wheel just short of locking point.
Want to know how many times those wheel sensors measure for a wheel lock per second? On the latest ABS systems, it numbers in the hundreds of measurements per second. And when it kicks in, brake pressure can be adjusted up to 10 times per second. A human being cannot replicate such performance.
But I’ve seen tests where a rider is able to brake faster without ABS than with ABS?
Yes, that’s very true but think about why. If a bike engages the ABS system, it’s because a situation is detected where the front wheel could otherwise lock. But ABS on a bike will only engage when needed, it’s not as if ABS engages when you casually slow at a traffic light. Older ABS systems on motorcycles (especially those that were pretty much a copy of car ABS systems) may engage too quickly and unnecessarily, but we’re a long way down the road from those today.
Therefore a bike with ABS will brake just as quickly as the same bike without ABS if the ABS isn’t activated. It is only when ABS is activated that it may result in longer braking distances and that is because the sensors are adjusting brake pressure on and off (or to put it better, more and less pressure is applied) to prevent a lock up.. If you were to lock a wheel when on a bike without ABS (and not crash), your stopping distance will also increase and will itself will be further than that of an ABS assisted stop. What you’ll find in the tests we go through further in is that ABS is intentionally engaged (in other words, a wheel lockup is induced) to measure the stopping distance, whereas for the non-ABS bikes, the rider is instructed to brake as best as possible without a lock up.
Just remember these two things:
An ABS equipped bike will stop just as quickly as a non-ABS bike if ABS isn’t engaged.
A non-ABS equipped bike will take longer to stop if a wheel locks than an ABS equipped bike when ABS is engaged.
I’ve locked my front wheel before and not crashed. It just takes good reflexes
Here’s a breakdown of how a human reacts to something:
- Mental Processing Time: This is the time it takes for a person to actually realize something. In our case, to realize that the front wheel has locked.
- Movement Time: Once the brain has registered a situation, a person must physically react. For us, that means releasing the front brake lever with your right hand.
- Device Response Time: The time it takes for the mechanical device to respond to the human input. Here that means the calipers releasing the disc.
So that’s what is required to unlock a front brake. The average human reaction time to audio stimulus (the sound of a locked front wheel) is 0.17 of a second. The time to then fully release the front brake is around 0.11 seconds. And the time for the bike to respond would be close to 0.02 seconds. That’s a total time of 0.30 seconds to unlock a brake – best case scenario.
But guess what? It only takes between 0.2 and 0.7 seconds to cause a crash from a front brake lock up. Once the gyrostatic forces of the bike reduce and the motorcycle starts to oscillate around its axis (those are fancy sounding words for how a motorcycle stays upright at speed), the bike becomes unstable and falls over.
So, at best you can unlock a front wheel in just under a third of a second. But even that might not be enough to prevent a crash when it only takes as little as a fifth of a second for a crash to occur.
Learners shouldn’t have ABS because it means they don’t properly learn how to brake.
This is another classic phrase you often read or hear. It’s a bit of a chicken and egg situation, because if a new rider doesn’t have ABS, they may not build up the desired skill necessary to brake properly when they first need it, resulting in a crash that may put them off bikes prematurely. Whereas if they had ABS that same situation might be forgotten as just a ‘moment’ and they’ll continue to gradually gain the required skills.
I suppose there’s a touch of logic to the idea it in that a new rider may not bother learning how to brake properly if they have ABS, whereas a non-ABS bike would force them to learn. Again, this misses the point that ABS is only ever activated if the onboard sensors detect a locking wheel. Practicing to learn on a bike with ABS is the same as one without – it’s just that the ABS is a backup. I would argue that the same people who don’t bother to properly learn or practice braking would do so whether their bike had ABS or not. Here’s a great summary from Bosch, one of the largest suppliers of motorcycle ABS systems on how one should brake on a bike with ABS:
The first rule of braking with ABS: brake as though you did not have ABS.
- Begin braking using the foot brake as far as possible.
- Pull the brake lever quickly, but not abruptly. Once the brake pads have fully engaged, increase the braking pressure quickly, and in significant amounts.
- When performing a full braking maneuver, brake on straight course within the ABS control range. Depending on the model, you can tell that the ABS has kicked in through a gentle pulsing on the hand and foot brake levers, as well as a tacking noise.
- When performing a full braking maneuver, always disengage the clutch at the same time.
- When braking in bends, increase the braking pressure gently to prevent the front wheel from slipping to the side.
- Always pay attention to the rear of the motorcycle when performing a full braking maneuver. If the rear wheel lifts up, you should reduce the braking pressure on the front wheel as quickly as possible.
All those above points are the exact same way you brake, ABS or no ABS. There is not a differing skill set.