Light tires replaced, original tires cracked and bulged due to my large amount of firewood. I had to lengthen the axle. 31 x 3/4" steel bar replaced with 32.5 x 3/4" It wasn't a surprise. Significantly heavier tire with better width. I was originally trying to buy a replacement for my 4.00 x 8 inch drives. It seems dangerous to fit heavier tires on lighter rims. I couldn't get anyone to mount them. I originally thought about going this route. I should have saved myself $45 and a lot of heartache. Either way, they do a great job of improving mud traction and increasing carrying capacity.