The lowered front helps handling and turn in. That can also be achieved by changing the front tire to 140/75R17 Avon Cobra. Now as far as the scraping it could be from the lowered rear, or it could be you are a really good rider and are taking it to the lean angle limit. Now that can be increased with a little rider technique that has you leaning out beyond the bike like racers do on the track. While riding aggressively with the amount of weight and tire size you need to really haunch down and lean your body out over the road like a racer does on the track. It would also help if the rear shocks were at the full length of 12.5 inches. No the OEM rear shocks are not very good. You need something like the Progressive 430, 440, 444 shocks to improve the handling. Also putting progressive front springs and 7 W fork oil make a big difference too. If your riding weight is near or over 220 lbs the rear shocks need the heavy duty springs.