Well, I've put on the 13oz today but I also put on a steel rear sprocket -1 tooth. I was really surprised how much difference there was going one tooth smaller in the rear. I was able to lug second gear into the corners nearly idling and had no problems with stalling. I ran mostly second gear and ocassionaly third on a little more opened stretches. The 13oz is almost too much weight now :bang: I'm going to try the new gearing with my original 7oz tomorrow and see how that works. If it's still too snappy, I'm going to have the 13oz milled down to around 10oz and try that. With the 13oz on the bike runs more like a 125, you have to really keep the revs up to get into the powerband. It reminds me of my old 250f, really mild down low and keeps climbing to where it's screaming on top. In wide open stuff it really didn't want to wheelie without pulling on the bars. It's much easier to ride, but you really lose the snappyness With the 7oz it really hooked good and was a ton more snappy, it wanted to wheelie through the first three gears. I think I've got my suspension as dialed in as it's going to get so that may be a factor in traction as well.