It’s the standard motorcycle safety system, but where did it come from?by Harry Fisher, on LISTEN 04:33
ABS is now as much a part of the motorcycling landscape as chain final drive and has contributed enormously to motorcycle safety. BMW was the first manufacturer to fit it to a production motorcycle but, in fact, it was initially developed by the young aircraft industry.
The Development of ABS
ABS is now an accepted part of a motorcycle’s electronics but it is a relatively recent application. The funny thing is, ABS was around for a very long time before it found its way to first cars in the and then motorbikes.
ABS, or Anti-Lock Braking System, was first developed alongside the fledgeling civil aviation industry. It was all very well for military and private - barnstorming - pilots to take risks, but when carrying paying members of the public en masse, safety had to be addressed and the risks minimised.
Passenger planes were heavy and, coupled with the state of many runways of the time - often grass - and the presence of ice in winter, braking from relatively high speed to a stop in a limited distance was always going to be risky.
In 1920 the French automobile and aircraft pioneer Gabriel Voisin experimented with systems that modulated the hydraulic braking pressure on his aircraft brakes to reduce the risk of tire slippage.
These systems used a flywheel and valve attached to a hydraulic line that feeds the brake cylinders. The flywheel was attached to a drum that ran at the same speed as the wheel. In normal braking, the drum and flywheel should spin at the same speed. However, when a wheel slows down, as in when it was about to stop quickly as the brake locked the wheel, then the drum would do the same, leaving the flywheel spinning at a faster rate. This caused a valve to open, allowing a small amount of brake fluid to bypass the master cylinder into a local reservoir, lowering the pressure on the cylinder and releasing the brakes. The use of the drum and flywheel meant the valve only opened when the wheel was turning. In testing, a 30% improvement in braking performance was noted, because the pilots immediately applied full brakes instead of slowly increasing pressure in order to find the skid point. An additional benefit was the elimination of burned or burst tires.
[As an aside, the modern ABS system was invented by Mario Palazzetti, an engineer at FIAT, in the early 1970s. He called it Antiskid. The patent was sold to German company Bosch who renamed it ABS. The first automobile application was in the Jensen FF of the late 1960s and the first fully electronic ABS was used on the Concorde supersonic air liner.]
Modern systems work to exactly the same principle, except that nowadays, detection and actuation is fully electronic, albeit still working on the principle of releasing the brake momentarily, many times a second.
BMW was the first motorcycle manufacturer to fit ABS, to the K100 of 1988. There were several issues. Firstly, the equipment was bulky and heavy - 11kgs, to be precise. Also, it was a little crude in its operation, prone to being snatchy and it actually increased braking distance.
There was widespread doubt about the technology. Racing legend Mick Grant argued that it would stop riders developing their skills and prevent experienced riders from locking the brakes in order to fall off deliberately if an unavoidable accident was about to happen.
In the end, the arguments against ABS were swept aside and, by the mid-1990s, more than 60,000 BMWs thus equipped had been sold. With improvements in technology, the system became infinitely better; smaller, lighter, smoother, more effective. At first, sports bikes and adventure bikes couldn’t use the system as they needed complete independence of front and rear braking. This all changed when Honda fitted its Combined ABS system which was an option on the 2009 CBR600 and Fireblade models.
By 2016, it was mandatory for every new motorcycle over 125cc to be fitted with ABS as standard. By then, of course, there was no argument as to the efficacy of ABS and the system has been developed - and continues to be developed - to work in conjunction with a whole host of measurement parameters, such as lean angle, torque and acceleration which is making riding safer than ever.