Alexhill7

Hi All, Used to ride a motorbike many years ago when i was 16, i'm 41 now, and had my full car licence since 1996. Question is, i understand i can ride a 50cc with no L plates and i don't need to do a CBT. If i do a CBT this means i can now ride a 125cc, question is, do i then have to put L plates back on, or does my licence mean i can ride 125cc without? I can't seem to find answer to this question anywhere Thanks in advance