26X3.5 on 90mm wide Specialized wheels. Wheels are temporary as I have a nice set of carbon wheels on order. I ordered just the frame/motor/battery and took apart three custom fat bike builds I have to build this one ultimate do it all Hydra Fat Bike. In total I’ll have three different sets of wheels that will work on this Hydra, 27.5 Plus, 26 Carbon for street and 26 Fat for trails/snow. Frame is supposed to ship Monday, can’t wait to get this party started.