I would ask for some help here please.

Me and my dad have both ridden our R125 (me on private land) and we both noticed the back brake does not seem to work. Either we arent pushing hard enough (I've tried my full weight (10 stone)to no avail). If this is normal and the pads just need wearing in or something thats fine if not we will take it back to the dealer since its under warranty still and get them to sort it

Cheers guys all input is appreciated

It should be working so as you'd notice, a light pressure on the pedal should be very noticeable-not that you should be using it anyway, yep get it back to dealer pronto, and when its fixed dont use it more than a light 'drag' just to 'level' the bike during heavy braking only time I use rear brake is when moving very slow in traffic etc-or during an emergency (when the prayers start)

yep get it sorted, full weight...it should have locked up well before that

also use it in the snow,,, it gives better control,,,,you dont want to lose the front end in a slide.