Thread: ABS off road??
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Old 08-27-2013, 03:11 PM   #40
Cheesehead Klompen
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Joined: Feb 2012
Location: Da frozen tundra eh? 1.5 mile west of Lambeau
Oddometer: 735
Originally Posted by Pantah View Post
I can't imagine wanting a system that can automatically turn off my brakes.
Its not that the ABS is turning the brakes "off" at any given time, it depends on what the ABS system is sensing with info from the wheel speed sensors. Putting it real basic, ABS tries to keep the wheels turning at all times within a speed differential thresehold, some wheel speed percentage slower than the actual bike speed. When I was working with Bosch, the differential was 20%, meaning for a wheel with the brake applied, if ABS sensed that wheel going more than 20% slower than the vehicle speed, ABS brake control is engaged until 1)the wheel speed matches the vehicle speed, or 2) the operator realeases the brakes.

So, any situation, WHILE braking, if a wheel remains turning slower than the thresehold value, ABS will engage/maintain control. A wheel sliding on pavement, asphault, concrete, dirt, gravel, sand, mud can cause ABS to engage. But moreso on a bike than a car, a wheel in the air, while brakes are applied even minimally, can slow the wheel beyond the thresehold very quickly and ABS will engage to release that brake. As long as the wheel does not speed up to match the vehicle speed, ABS control is engaged/maintained.

It gets real interesting if the bike also has ABS integrated into stability control, like it does on the later model GS. Stability control means the ABS is used to maintain tire contact, inhibit stoppies, etc. If the ABS senses the rear wheel is going slower than the thresehold value due to that wheel being in the air, ABS stability control releases the FRONT brake to bring the bike down. That is why ABS on a bike with stability control, in areas that can cause the rear wheel to go airborne (like over rocks) should also be shut off.

Perhaps the Yamaha Tenere doesn't have stability control and that may be why it works better off road.
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