Property modification of an inorganic surface can be readily achieved through the use of macromolecules chemically grafted to the surface at specific functional sites along the chain. While numerous efforts have addressed the properties of linear chains rafted at one end (tails), relatively few have extended such studies to include double-tethered chains (loops). In this work, we consider loop/tail mixtures in which both chain species possess an identical number of repeat units. Bond-fluctuation simulations have been performed to ascertain the effects of composition, chain length and surface density on the segmental density distribution and layer height of each constituent species and of the mixture. These results compare favourably with self-consistent field predictions for bidisperse mixtures of grafted tails differing in length by a factor of two.