>Roadworthiness and MOT certificates are not related.
What Mike says. Think about it - if the brakes wear out, say, six months after a MoT, is the vehicle still roadworthy just because the vehicle isn't due another MoT for six months?
It's said innumerable times that a MoT only means the vehicle is (should be) roadworthy when you ride/drive it away from the test station. The other 364 days, 23 hours and 59 minutes, having a 'valid' MoT means far call.
Any time you use a vehicle on a public road, it has to be roadworthy, whether it's brand-new and not in need of an MoT for three years or over forty years old and not in need of an MoT. And it is always the rider's/driver's responsibility that the vehicle's roadworthy.