Thanks to KYCycles selling me a rear wheel, I now have a roller. I have the bike sitting on a 120/70- 17 front tire and the only rear I had laying around to spoon on the rear was a 190/55. With a proper size rear that will eventually be on there, this will lower the rear some and rake out the front geometry a bit.
So, some observations... parked next to my RC51, it is a looooong bike. Throttlejockey asked about the wheelbase- it's right at 58.5" axle to axle (the ST, not the RC). Also, the GSXR and RC51 trees both have 30mm offset, and the ST front has more rake than the RC. I measured the ST lower tree I have, and the offset is 45mm, which means that with the 30mm offset GSXR trees, I gain 15mm of trail without factoring in the shorter front end. So, the shallower offset tree moved the front wheel back by 15mm, and according to my measurement of the wheelbase, I'm only 12.7mm shorter than stock, so I think the front end geometry is going to be fine, but will still be using a steering damper and will make the first couple hundred miles cautious ones. Also, as the bike sits, the front only has about 0.5" of static sag with the preload set halfway, so I think the front springs and valving will be fine. The rear, however, is stiff So stiff that when I put all my weight on the frame above the swing arm, the forks compress while the rear doesn't move at all. While I suspect I'll be adding about another 125- 150 lbs. to the bike, I don't see that changing much with the rear spring. I will probably throw scales under the wheels and send the rear shock off to Race Tech for a spring and valving.