Foams- Hey what's up? About to go to bed and saw your post. Purple Fronts and Greay Rears normally but I have been using Magentas and they seem to work really well on medium bite tracks for me although purples are still good also. On really high bite tracks that black groove I think I will probably stick with purples so that the front end doesn't bite so hard and try to "screw itself into the ground" as we call it which is the prelude to a traction roll. Too much grip is a bad thing because it also slows down corner speed which is why Josh and Dave and others have the front arms parallel instead of the back link being in the inside hole for all of that reactive caster. BTW, I don't see a pic anywhere of whaterver it is you're talking about. If it is the little wing that mounts in the batter slot it's to brace the batteries. Don't use it because it's not needed if that is what you're talking about. If it's something else I need you to describe it or get me the pic.