I agree with breno flip the sprocket, yeah it sucks but its right. I run factory huffy 2.25" tires and have about a quarter inch of clearance between the tire and chain. Keep the tensioner and align it properly as it may give you more clearance on the lower part of the chain than you have now. BTW I would keep the fatties as they will make your ride smoother on your back side. If you want speed and a stiff ride get skinnies, just watch them pot holes with a really good eye. Good luck.