Stage 1. Measure your head. Get someone else to do this bit for you, it is really important. Measure the circumference across the forehead, above the ears and round the back of the head as shown in the diagrams. Measure in centimeters.

Stage 2. Match your measurement to a helmet size.

53-54 = XS

55-56 =SMALL

57-58 = MEDIUM

59-60 = LARGE

61-62 = X-LARGE

63-64 = XXL