I had the opposite experience, I lowered Wendys bike 2" in the back and the pipes would scrape once in a while if the road or drive entrance was sloped the wrong way too much but then I lowered the front 2" and it scraped worse and much more easily. I agree it does matter what pipes you have as to how or when they would scrape. Hers are the stock BA slash cuts from 04, gutted of course!

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!