I've been searching and reading for 2 days now and I still haven't found my answer. I just picked up a 2004 525 SMR with a 5 inch rear wheel. Currently the bike has a Bridgestone 160-60-17 BT020 rear tire. I've checked everything and it's aligned properly, bearings are good, spokes are good, chain slack good, spacers are in place, ect.. The issue is the chain has taken off at least 5mm of rubber off the egde of the tire. The rim hasn't been touched.. There is only about 5mm of space on the other side so adjusting the spokes to offset the wheel won't help. I know tires differ in size from brand to brand and even model to model so I guess my question is.. anyone out there with the same bike know of a tire that will work? I also read that some guys switch to a 4.5 inch rim on this bike but I'd rather not do that. I also don't want to swap the swingarm.. I don't think going to a 150 is a good idea either due to the width of the rim, I just want a tire that will fit without rubbing the chain so bad. Thanks in advance.