Looking To Do Plus Size Tire

Hi and welcome

I don’t know the answer but someone on here will, although I am intrigued as to why you want to go bigger?

 

110/80-18 fits fine on front, I have a BT023 fitted in that size. 160/60 apparently fits on rear, but will reduce rolling radius and drop the rear end a few mm. This will make the bike steer a bit more slowly. No problem if you're OK with that.