Not sure if the slots in GR9-s are wide enough to cram the straps through but it's worth a shot. I do think a pair of $10-15 BMX platforms work better with this setup and if you get the plastic ones they are lighter as well. I've got some YNots and Haro Small Block pedals which have a nice concave to them and they are perfect. Had some Fyxation straps that were too floppy and hard to get into. YNots and Holdfasts are much better.