Graham Stapleton, who comes from Dixons, has been appointed as the new chief executive of the Halfords Group, the British bike and automotive accessories retailer, replacing Jill McDonald. Benefiting from a “staycation” summer in Britain, Halfords reported in a preliminary statement a 4.8 percent increase in total revenues for the 20 weeks ended Aug. 18. On a same-store basis, cycling sales went up by 5.2 percent, reflecting good growth for premium bicycles.