When Rip drives up to help defeat the wicked bikers, there are at least 12 motorcycles parked on the side of the road. But as he goes through and cleans house, there are only 10 bikers total (6 guys and 4 women).
When rip is about to run over the motorcycles you can see a guard on the truck below the bumper and after he gets out of the truck the guard is gone.