In the wet, what would you do if the ABS is triggered ?

[wjbertrand]

As a follow on, I remember thinking at the end of the motorcycle ABS training how neat it would be to just have an "emergency brake switch".

I forgot all about that thought until I spent a day at Mercedes Brooklands test track driving all their cars. Turned out all the high performance cars had exactly that (ie emergency brake switch) , it was surreal to push the brake pedal quickly and then have it move all the way down under its own force, basically , if the system detects that you want an emergency stop; it gives it to you. It's is basically full on braking that activates ABS and lets it do its thing, no messing , no indecision, its the full 100%.

This is becoming pretty common kit these days. My 2002 Lexus IS300 had this feature as does my current 2013 Mustang GT. I think the system works by monitoring how quickly you get off the throttle and onto the brake to determine if an emergency stop is being requested. The system then takes the brake system all the way to ABS engagement until you get your foot completely off the brake. The Lexus system seemed to jump the gun occasionally and then had a noticeable delay releasing the brakes after lifting your foot completely off the pedal. Just driving the car in an agressive but controlled manner would sometimes annoyingly trigger the system. The Ford system seems a little better tuned to actual panic braking events while allowing more aggressive driving without intervention. Either system could save your bacon if you're an ABS lifter.

 

[aSTerix]

#3 is a non-choice. You can pull harder, but there is no pulling through the rumble.

I have found on all the ABS bikes I have ridden that there is a change in the lever/pedal when you pull harder after the rumble starts, it could best be described as a smoother rumble. It tends to get overlooked because of everything else that is going on plus the noise from the calipers and tyres but if your looking (feeling) for it then you will notice the difference. (From my personal experience, its a more comfortable feel on my fingers and foot than trying to hold the lever in the 'middle' of the rumble)

 

[aSTerix]

In straight line emergency braking, I've never felt the need to let up if the ABS kicks in

Based on what I observed and experienced on the training course, it is a strong possibility that riders are actually unconsciously releasing the lever/pedal when the ABS kicks in. Its hard to detect without specialist sensors on the bike. So although the intention may be to 'not let up', its possible that 'letting up' is actually what is happening, albeit inadvertenly.

 

[aSTerix]

Maybe a better poll would have been to ask the question, "How many hours do you practice e-stops in a parking lot every year?

I think this would be an interesting poll .

I had a look at the Poll option and it is only multiple choice so the choice of possible answers would need some thought. If you decide to run the poll then I will happly cast my vote .

 

[aSTerix]

A motorcycle is not a jet, but we always trained to let the ABS cycle during an aborted takeoff. It was proven in the simulators (and IRL) that doing so resulted in significantly shorter stopping distances. I've seen several motorcycle You Tubers and Bloggers state you should back off the brakes until the ABS does not cycle. I'm no expert, but that does not fit with my experience in the aviation world and seems to negate the whole purpose of ABS.

I was surprised to find out that on the 777 (and later) the ABS still worked when it was only accumulator pressure, thats how critical it was seen. (Prior to 777 it was disabled on accumulator only)

 

[aSTerix]

The biggest issue I hear of with ABS, or at least the thing that sticks in my mind is that some people ease off the brake when the chattering starts. It is foreign to them and they let off the brake to stop it.

That was my main takeaway from the training course, I was in this category of "some people" and didn't realise it !

There are riders who consciously ease off and there are riders who unconsciously ease off and these two categories made up 100% of the course attendees ! After the training most of the riders transitioned into the category of "pulling through to max braking".

 

[drtyrrel]

But, how many are willing to practice to the point of dumping your bike several times before you become well trained enough to know where that point is?

Some of us find that point unwilling when practicing.

 

[drtyrrel]

The objective of an emergency stop is to stop in the shortest distance possible at a certain speed without skidding (threshold braking). Any skidding or application of ABS will lengthen this distance. ABS releases then reapplies the brakes when the tire starts to skid. If you can stop at this threshold every time you can brake better without ABS. ( good luck with that) When I coach a BRC2 and the student has ABS I have them keep braking harder each pass until I hear the ABS kick in. I then have them back off just a hair on the next run until they don't trigger it. I do the same if I hear them skid but I don't have them skid on purpose because I don't want to have to pick their bike up. If the back tire skids I have them hold it until stopped. If the front tire skids release it then reapply with less pressure.

 

[beemerphile]

I have found on all the ABS bikes I have ridden that there is a change in the lever/pedal when you pull harder after the rumble starts, it could best be described as a smoother rumble. It tends to get overlooked because of everything else that is going on plus the noise from the calipers and tyres but if your looking (feeling) for it then you will notice the difference. (From my personal experience, its a more comfortable feel on my fingers and foot than trying to hold the lever in the 'middle' of the rumble)

I would think that you are just suppressing the hydraulic feedback from the system to the brake lever. I don't think that the brake system's response to a locked wheel is any different if you press harder.

 

[aSTerix]

I would think that you are just suppressing the hydraulic feedback from the system to the brake lever. I don't think that the brake system's response to a locked wheel is any different if you press harder.

yes I would concur with your thoughts, I find it a more comfortable place to hold the lever and pedal and also ensures that the ABS is fully functional and not being modulated by the rider (unless of course the rider wishes to modulate purposely )

 

[aSTerix]

I voted for all 3. Does that help?

 

[wjbertrand]

Based on what I observed and experienced on the training course, it is a strong possibility that riders are actually unconsciously releasing the lever/pedal when the ABS kicks in. Its hard to detect without specialist sensors on the bike. So although the intention may be to 'not let up', its possible that 'letting up' is actually what is happening, albeit inadvertently.

I think this is true and the same has been found for car drivers with ABS. I'm fortunate to have taken part in some brake testing for MCN Magazine so might have the advantage of some extra training and experience. With an ABS bike the first thing off the trailer (brake testing wise) was a full ABS engaged stop from 60 MPH. Most bikes are calibrated to decelerate at about 1G so typically stop in around 120-125 ft. I could come close to but I never was able to beat the ABS stopping distance on the same bike without ABS or without the ABS engaging. Lee Parks and our some of our racetrack experienced testers could sometimes beat the ABS by a few feet, but never on the first try. Participating in these tests with these guys got me very comfortable with staying on the brakes and letting the ABS do its thing. One note on the Honda ABS II systems like the '96 and later 1100s and all 1300s have is that the pulsing is not very obvious (feels more like a fine ratchet slipping to me) compared to some bikes where you feel exaggerated pulsing in the pedal and lever. Perhaps riders with these Honda ABS II systems would less often let off when ABS engages.

 

[aSTerix]

I think this is true and the same has been found for car drivers with ABS. I'm fortunate to have taken part in some brake testing for MCN Magazine so might have the advantage of some extra training and experience. With an ABS bike the first thing off the trailer (brake testing wise) was a full ABS engaged stop from 60 MPH. Most bikes are calibrated to decelerate at about 1G so typically stop in around 120-125 ft. I could come close to but I never was able to beat the ABS stopping distance on the same bike without ABS or without the ABS engaging. Lee Parks and our some of our racetrack experienced testers could sometimes beat the ABS by a few feet, but never on the first try. Participating in these tests with these guys got me very comfortable with staying on the brakes and letting the ABS do its thing. One note on the Honda ABS II systems like the '96 and later 1100s and all 1300s have is that the pulsing is not very obvious (feels more like a fine ratchet slipping to me) compared to some bikes where you feel exaggerated pulsing in the pedal and lever. Perhaps riders with these Honda ABS II systems would less often let off when ABS engages.

For me , the best takeaway from my training course was my willingness or perhaps confidence to practice full emergency stops using ABS from pretty much any speed and to also do this on wet roads at similar high speeds.

(Note: I did find that emergency stops from high speed in the dry tended to boil the brake fluid, eventually necessitating a complete fluid change to get optimal performance back)

This is stark contrast to me having a marked reluctance to practise a full emergency stop in the wet above 80kph (50mph) on a bike without ABS.

When I step back and think about this rationally; I shouldn't therefore be riding above 80 kph (50mph) on a non-ABS bike in the wet, but I did !

(I now only ride ABS , apart from my Matchless but that doesn't go above 50 mph anyway and has terrible brakes)

 

[sky.high]

The first big test is to discover if the bikes ABS is actually functional, as previously stated I don't think mine has ever been activated, its now been idle for 15 years, if the factory didn't exercise the ABS then maybe it has never operated. I really don't relish the idea of trying it out for the very first time but this discussion has now set me on that path of discovery, wish me luck!

 

[aSTerix]

On an aside, if anyone has ever done an emergency stop with ABS whilst towing a trailer, I would be very interested to know how it felt and if it required a modified braking technique

 

[ad.hom]

My old man always drummed into me - "this electrical gimmickery in vehicles will quit working far sooner than the mechanical stuff. Don't trust electrics to save your life."

As a result, I ride/drive such that if I need ABS, I've probably screwed something up far earlier than the current moment.

I've had to use ABS once in anger - vehicle in front of me coming to a dead stop on a motorway (after it's driver hit reverse at 70mph). I stood HARD on the brakes & wondered WTH the chattering was.

So on a bike, if ABS kicks in, I'll hold the anchors firmly. If I'm mid bend & land in a bush, hopefully I'll have some time to think about what I could have done better 500yards before the bend.

 

[OkieRider]

This is my first ABS bike. I've never felt the need to have them and would have chosen a ST without them if one was available to me. If I ever set off the ABS, I'll pull the seat cushion out of my ass and type something about the experience.


So, it hadn't dawned on me that I might need to do anything differently. I read a couple articles. I've experienced ABS in cages. The thing that I find the most interesting is the few ABS materials I have read are all about maximum braking and stopping in an emergency. Certainly, there is a time for that. I've never experienced it, but I know people who have. Some succeeded. Some didn't. YMMV, but my own experience is it is often better to ride through many types of conditions rather than to stop. Obviously, that's not always true, but that philosophy has carried me for a long time.

 

[aSTerix]

The first big test is to discover if the bikes ABS is actually functional, as previously stated I don't think mine has ever been activated, its now been idle for 15 years, if the factory didn't exercise the ABS then maybe it has never operated. I really don't relish the idea of trying it out for the very first time but this discussion has now set me on that path of discovery, wish me luck!

How did you get on with your testing your ABS ?

 

[JetRanger]

A motorcycle is not a jet, but we always trained to let the ABS cycle during an aborted takeoff. It was proven in the simulators (and IRL) that doing so resulted in significantly shorter stopping distances. I've seen several motorcycle You Tubers and Bloggers state you should back off the brakes until the ABS does not cycle. I'm no expert, but that does not fit with my experience in the aviation world and seems to negate the whole purpose of ABS.
As I said earlier, a bike is not a jet and the sophistication of the ABS system on a bike may not equal that of a jet costing tens on millions of dollars, so my aviation experience may not translate into the two-wheeled world. That said, I have seen many pilots who thought they were smarter than the ABS go off the end of the runway (during sim training), while I just stood on the brakes, maintained directional control while the ABS happily chattered along and I would stop well short of the end of the runway. Yes, a simulator is not the real world, but it's uncannily accurate and I have aborted takeoffs IRL, using the ABS and always met or beat the calculated abort distance. Of course, good braking technique is still required on a bike, i.e. loading the front wheel then brake hard vs. jamming on the brakes, but I'm guessing the average rider should allow the ABS to cycle during a panic stop. I would love to see some real-world data on motorcycle stopping distances using both techniques.

ABS was designed to keep aircraft from locking a main gear wheel and running off the edge of a runway. Stopping distance is increased but they have no traffic to contend with.

On motorcycles ABS effectively prevents wheel lock up thus allowing us to maintain control as we (hopefully) steer around or away from a surprise obstacle. Motorcyclists tend to steer where we look if our training and experience kicks in.

In cars, considering the increased stopping distance with ABS and average driving skills, the average driver will probably collide with a surprise obstacle rather than turn away from it since they will probably be fixated on the offending vehicle.

In a car, I doubt that ABS prevents collisions. I remember seeing stats indicating an increase in collisions in ABS equipped cars (I wish I could remember the links but I'm getting old).

Just my 2¢.

 

[Andrew Shadow]

I remember seeing stats indicating an increase in collisions in ABS equipped car

I remember reading a report that claimed that initially, when ABS first became common on automobiles, there was an increase in both rear-end collisions and roll-overs. The reason for both of these was that people tail-gated more and entered curves with higher speeds more often believing and trusting that the ABS was all powerful and would save them. To solve those problems we now have automatic breaking and anti-sway systems to compensate for our ever increasing inability to drive well.