The shape of the slot in the plastic grip allow the straps to come out without cutting them.

For the easy wheels, as said, my Birdy had no factory mounted rack.

I first installed the H&H titanium rack to add less weight.

When this rack failed, I bought a R&M rack that comes without the R&M easy wheels. Those easy wheels (which are I think aggressive inline skate wheels)+bolt+spacer are sold separately as a kit that I didn't bought because I wanted to keep using rear pannier.