Is there a way of defining the position for these supports (left and right) ? - these are the two (LH and RH) that are forward of the looped support/handle and terminate just bolted to each side of the rear mudgaurd. Eg. so many inches fwd of the hinge, or maybe in line with the seat supports etc. I hate to drill the mudguard only to be told after that it's incorrectly positioned.