You can put the floor plates closer than 6" apart if you want. You'd just need to turn both handlebars the same direction(push bike #1 in, turn handlebars to right stop, then do same to bike #2). I do that regardless of how close the bikes are, because it gives me more room to get between the bikes(and I need more room than I used to). Just be sure to straighten the bars before pulling the bike out the latches when you arrive. You can also stagger the bikes if you have multiple rows of bikes and get them very tight. If you overtighten the bolts, you'll actually warp the floor plate(not crush the mushroom spacers). You can fix that by flipping the floor plate over or replacing it. Of course you'll also need to make sure you don't overtighten the bolts the second time. It doesn't take much torque at all. In destructive testing the bolt heads gave out before the washer underneath was an issue, so the oversized under floor plates are more useful for uneven surfaces(pickup truck beds) than for extra strength under a plywood floor. That said, in 15 years I have yet to see the bolt head pop off anywhere outside of that testing facility so I doubt anyone will experience that in the real world.