Grumpy, I take mine to PSS at the Caerwys junction on the A55. They use a decelerometer for brake testing and yes you are absolutely right about the modern roller brake test. The Mog is way to light to afford adequate friction under braking and the multi variable readings you get will predict nothing. Made worse by the fact that drums over brake momentarily before becoming consistent in brake force. This causes the tyres to jump or skip on the rollers.
