Geoff2 said:
ABS will not stop you quicker in icy conditions, in fact most books tell you to turn the ABS off when driving in icy conditions, purley for the reason that on ice, the wheels will immediately try to lock and the ABS will release. You will effectively have no brakes at all.
The true benefit of ABS brakes is not in the main, superior braking or shorter stopping distances. It is to keep you in control, by keeping the wheels turning under severe braking in an emergency stop situation. Therefore because the wheels keep turning, stopping distances on ABS machines will be greater than on non ABS equipped machines under dry conditions. Do not fall into the trap that your ABS will stop you, it wont, it WILL keep you in control to be able to steer
S'right!
The quickest way to stop is to lock the wheels. Maximum friction, maximum retardation.
The problem comes in maintaining control in what is after all, a skid.
ABS will extend, albeit slightly, braking distances for two similar vehicles, same load, same speed, same brakes etc, etc.
It has been deemed beneficial to allow the additional element of control provided by ABS.
Most modern ABS systems now cut out below 5mph. This is because the phenomena of 'no brakes' at low speed on slippery surfaces where the ABS would release the brakes before any retardation could occur.
I have experienced this with an older application. Ford Sierra 4X4, on fresh snow. The ABS prevented the wheels locking and breaking through the snow to the road surface. It really was a 'no brakes' situation, fortunately only at 10 to 15 mph.
On a bike ABS has a slightly different function. With four wheels you are unlikely to tip the vehicle over if you lock the brakes. ABS on a bike does reduce the chances of this but doesn't remove it all together.
Back in the very early days of BMW ABS (bikes), I was lucky enough to go to the launch and have the opportunity to ride the ABS kitted K's at TRRL.
BMW had research that showed there was no need for 6 piston calipers and massive discs. That most riders of bikes with these "Carlos Fandango" brakes rarely used anything approaching 50% of the braking capability, even in emergency braking. One of the main reasons was fear of locking a wheel and losing control. This research was corroborated by TRRL who at the time were looking into deformable leg-shields and tank mounted secondary safety systems (anyone remember the MCN photo's?)
BMW chose to stick with their single piston brakes as a demonstration that if the rider had the confidence (afforded by ABS) to use the brakes to their full potential, the stopping power was more than adequate for road applications.
When they launched ABS equipped bikes, BMW went out of their way to state that ABS was not intended to be an aid to performance, merely an aid to braking and that the laws of physics still applied!
Back to the original question. It's a non-question really. I doubt if anyone who has specifically bought a non-ABS bike will ever say that they wished they hadn't!
Some people will buy a bike without for financial reasons, others because they say they truely see no advantage, some don't like the added "complications" of ABS brakes.
I am an advocate for riding according to the prevailing conditions but to say that ABS as an aid to further safety is rendered unneccessary by this approach is just wrong!