OK all you fat tire users out there. Here's a question for you. How much tire growth can I expect out of a set of 33.5-17/16 D1 Good Years?? The ones that I have now measure right at 109.5" circumference and they're about 2/3 worn out. Any ideas? I'm trying to figure what gear to run and I want to get a little more accurate idea of my trap speeds and RPMs. Thanks.