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Front or Rear Brake ABS on dirt?

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That's not the point. Electronics have way better reaction timing to wheel locking than a person does. I don't see why brake pulsing couldn't be a benefit.

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ABS benefits the unskilled rider/driver. Tests have shown that a professional rider/driver without ABS can stop shorter and have more control.

'Threshold braking' is applying so much braking power that the machine is constantly on the ragged edge of a skid, but not quite. ABS skids, lets the wheel rotate, then skids.

On street car tires, you can hear the tires howl in protest but there will be no skid marks. If any rubber is left on the ground, it is a perfect match (Like a photo copy) to the tread pattern, right down to the sipes.

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ABS benefits the unskilled rider/driver. Tests have shown that a professional rider/driver without ABS can stop shorter and have more control.

 

Both the Mercedes-Benz and BMW racing teams and most people who race late model Corvettes use full 4 wheel independent ABS systems and love them.  It simply takes one part of the equation off the table and allows the driver to focus on other things.  These systems are not limited to their ability to control straight line braking either.  My experience with any out-of-the-box Corvette built since '98 or so, you can be drifting into a high speed corner, or have the two wheels on one side off the pavement, and mash the brake as hard as you like.  The only result is that the car will slow down at the maximum possible rate.  Under conditions like that, no amount of driver experience can do what the system does, which is to individually broker braking force to each wheel independently.  The car even connects the ABS to a lateral accelerometer that wakes up the system in hard cornering maneuvers before the brake is even touched to reduce latency.   

 

As far as rubber marks, 'Vettes leave them on the ground, and so does the advanced Bendix-Telefunken used on the German stuff. You can only really see this on a clean concrete surface, usually.   They operate by detecting speed reduction outside of the programmed limit, and result in a net 5-15% wheel slip, which is where the most stopping power is generated.  

 

What it is is freaking incredible.  

 

The problems for an off-road race bike would be the weight and electrical complexity, but it would seem to be particularly advantageous on bigger, heavier adventure bikes, or at least at the front wheel.  

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Would only really be useful on a front brake for a dirt bike. Even then I think the ground moves to much it would get confused. Lots of big bikes run ABS 

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Most BMW R1200GS riders turn off the ABS when riding off-road.

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Its worth a try.

Its a simple enough system.

Does anyone have any links to results on any experimental systems? Seems like someone would have tried it by now.

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Most BMW R1200GS riders turn off the ABS when riding off-road.

Heard its usually after their first face plant and arguing with the experienced guys that told them to turn it off. Never ridden one myself so I don't know the specifics of why it does not work well offroad.

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Heard its usually after their first face plant and arguing with the experienced guys that told them to turn it off. Never ridden one myself so I don't know the specifics of why it does not work well offroad.

 

The ABS barely lets the  bike have any braking because of all the wheel slip off road. On road it's a crutch for the incapable.

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IMO ABS, traction control, stability control, etc. Have no place in any form of racing, especially bikes. The whole point of racing is to test the riders/drivers. And all these electronics are just taking away from it. The right place for these things is everyday cars. I've had 4 friends wreck cars this year because of inexperience. Me? I'm still fine...

Edited by LiamRM212
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One of the things that makes it a more difficult technical problem with a bike is the lack of a good vehicle speed reference.  A car has four wheels that are monitored, and each must stay within 15% of the speed of the other 3.  A motorcycle only has two, so the likelihood of getting bad speed info from either one due to slippage is greatly increased, complicating the matter.  I'd guess it's a long way from working as well as it does in the 4 wheel world.

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One of the things that makes it a more difficult technical problem with a bike is the lack of a good vehicle speed reference.  A car has four wheels that are monitored, and each must stay within 15% of the speed of the other 3.  A motorcycle only has two, so the likelihood of getting bad speed info from either one due to slippage is greatly increased, complicating the matter.  I'd guess it's a long way from working as well as it does in the 4 wheel world.

Thanks Gray for the valuable input. For the people that say it takes away from the sport because it could make it too easy, I don't understand. If everyone thought like that than we would all be riding air-cooled rigid frame bikes with no knobbies. New technology isn't always bad.

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One of the things that makes it a more difficult technical problem with a bike is the lack of a good vehicle speed reference.  A car has four wheels that are monitored, and each must stay within 15% of the speed of the other 3.  A motorcycle only has two, so the likelihood of getting bad speed info from either one due to slippage is greatly increased, complicating the matter.  I'd guess it's a long way from working as well as it does in the 4 wheel world.

I think the 15% slip may be another variable in the effectiveness of abs off road. Pavement and rubber tires are all pretty close, and for racing it's optimized for the given combination, but in an off road scenario, where tires very from speed way tires to paddles, it would be hard to get the right percent slip. It's an even bigger issue if you think about how much things can vary in a single ride. 

 

I wonder if a gps based system, along with normal wheel speed monitoring, would be successful? It would have to be a very quick gps system (Maybe 200hz?), but we have those now, just not cheap. 

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Thanks Gray for the valuable input. For the people that say it takes away from the sport because it could make it too easy, I don't understand. If everyone thought like that than we would all be riding air-cooled rigid frame bikes with no knobbies. New technology isn't always bad.

 

Not the same thing. I don't need brakes to release themselves because I'm stupid or incapable. I don't need traction control because I'm too stupid or in capable of throttle control. Racing is man and machine against man and machine , not computer against computer.

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I have a triumph Tiger and anytime I go off road ABS and traction control gets turned off.

 

Traction control- The computer responds to lifting the front tire so it drops power and puts the tire down. Every day I go riding I need to loft the tire over something and with traction control on its a pain. Not to mention when you want to slide it feels like a turd.

 

ABS- Terrible off road, in loose traction the brakes feel like they don't even work. I swear when your dropping down a hill it feel like for ever when the computer is compensation for lock up and you accelerate.

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