It is pretty much a stock size rear tire. Well as close as you can get converting to metric sizing. There is a lot of clearance. I was worried a bit once I put the tail light assembly on which holds the license plate. It looked like it might be a bit close. However, I hopped up and down with everything I had to compress the rear end and the plate never gets closer than 2" inches to the rear tire. Add in that I have the shocks at their lowest setting so when I adjust them to raise the back end some I will gain a little more clearance. This is without a doubt the smoothest rolling bike I have. When pushing it around it feels like it just floats.
However, I ran into a huge issue yesterday. I started hooking up all of the wiring yesterday and adapting the controls I am going to use to attach to the stock wiring. I was mostly done when I came to a show stopper. When I dropped in the battery I noticed the problem. I can't get the seat on with the battery in. The bracket I welded in to anchor the front of the seat sits just in front of the battery. With the battery installed I need about an inch of clearance for the seat to be able to slide in. After a lot of thought I think I can get a smaller than stock size battery. I currently have a Scorpion YT12C (180cca, 12a/h). I looked at the lithium batteries, but great googly moogly are they expensive. So I started looking for a smaller dimensioned AGM battery. I found a Scorpion YT9C (130cca, 9 a/h) that should give me 1/16" of clearance at the top. I will have to cut off the upper front piece of the battery box so that I can attach the ground wire to the battery, but I can live with that. I will be running an LED headlight that uses 19 amps less than the stocker, no turn signals, and all other lighting is LED so I think I should be good with the a/h rating.
The icing on the cake yesterday was that none of the wiring works. I have power at the connector in the headlight bucket, but nothing turns on. Not a light, horn...nothing. So I think I have a ground issue somewhere.