A smoking article (8) comprises: a combustible heat (2) source having a front portion (2a) and a rear portion (2b) an aerosol forming substrate (10) downstream of the rear portion (2b) of the combustible heat source (2) and a wrapper (40) circumscribing the front portion (2a) and the rear portion (2b) of the combustible heat source (2). The wrapper (40) is in contact with the rear portion (2b) of the combustible heat source(2). All or part of the front portion (2a) of the combustible heat source (2) is of reduced diameter compared to the rear portion (2b) of the combustible heat source (2) so that the wrapper (40) is radially spaced from all or part of the front portion (2a) of the combustible heat source (2) by an air gap (42) of at least about 0.5mm.
