Some of the OEM bolts can be tough to remove. Some are fine. It's amazing the range of difficulty for that OEM bolt.cool. yeah, when we installed malbiniak's we had to work pretty hard to get the oem bolt out, needed a breaker bar on both sides of the bike, iirc... don't recall if the impact wrench did much good. got lucky actually, almost tweaked one of the nuts, but we got it.