Molecular wheels attract continued attention, partly due to beautiful structural aesthetics, but also because some show fascinating and potentially useful physical properties. In the field of molecular magnetism, molecular wheels of 3d transition metals came into prominence in the late 1980s and early 1990s with the publication of [Cr and [Fe . The former has inspired the development of a large family of homo-and heterometallic Cr wheels including the first examples of odd-numbered wheels that display topological frustration, with potential as quantum bits in information processing. The latter, and other antiferromagnetically coupled even-membered wheels, are characterised by a diamagnetic spin ground state and display interesting quantum phenomena and spin dynamics, including tunneling of the Néel vector, spin-multiplet mixing effects and magnetic level repulsions. The intervening years have witnessed the publication of wheels of all the 3d metals with nuclearities up to eighty four. In Co II chemistry early examples of wheels included a dodecanuclear cluster built with a substituted pyridone and an heptanuclear Anderson wheel stabilised by tripodal alcohols, both display ferromagnetic exchange interactions.