ABS Shuts off + Randy Pobst

[RS2 CQ]

Anyone know why my ABS would shut off when going over bumps? It is quite annoying especially at the track where I accidently locked up my brakes and put a flat spot on my slicks.

BTW- Randy Pobst, who won the Speed World Challenge Series a couple of years back in the factory Audi RS6 drove my car yesterday at ButtonWillow race track in California. First if you ever get a chance to go for a ride with a pro race car driver, Go for it, it was incredible!!! He also REALLY liked my car-1990 US coupe with a RS2 engine (ADU) and all the RS2 goodies + coil-overs and big brakes. He was very impressed by the engine and set up. Cheers to Mihnea for the program job, you have Pobst's seal of approval!

[s4_rider]

It could be the sensor moving around or the toothed wheel (gives the pulses to the sensor) is broken and moves around at bumps an/or sudden speeds. Mine did this at sudden speeds.
Or maybe it is the sensor cable that bends and makes a open connection.

[BRY]

I have just had the exact same problem as pictured above. There was a slight metallic clicking noise at low speed which could not be traced until the garage did the wheel bearing and found that the ABS ring had cracked / split as shown above.
One to look out for.