As I said, it's often, but not always, down to bad teaching methods. I accept that nerves will always play a part. The pupils of ours who do cock up, could normally be attributed to nerves. The swerve test is the only exercise that anyone complains about, yet we've had only two fail for it since it came in at the end of april. One clipped a cone (cos he rode with his feet pointing out!), and one for not achieving the speed (on a 500). Everyone on a 125 has passed without issue. We use Yamaha YBR125's and Suzuki RV125 Van Van's (which have to be about to blow up in second gear to achieve the speed). Both bikes are fairly nimble, but are not sports bikes by any stretch of the imagination. But if you use the right techniques, any bike can be hustled through the manoeuvres.

Incidentally, the swerve cone is set 0.3m off to one side, not 3m...