Why would they take it. At 17 they can ride a geared 125cc, on L plates for the cost of a CBT. The only licence they can do is the A1 which means they can ride a geared 125, the only bonus is they lose the L plates and can carry a pillion or use a motorway (not appealing on a 4t 125)...... for those awesome extras over just a CBT they will pay almost £150 in test fee's (including theory) and that is if they DIY it and pass all parts 1st time using their own bike. If they need lessons the costs multiplies in to the many hundreds.