hi
could i put these tyres on or would i get smashed

140/70R17 BT-090 PRO RADIAL on the back
110/80ZR18 BT-012SS on the front

good or shite?

For starters, did you put an 18 inch front wheel on your bike? If not, then that won't work. Many have experimented with non-stock sizes for the rear. There are many posts to be searched for that. To me it looks doable, but I always stay with stock sizes. Front 110-70-17, rear 130-70-17.

  -Anti