Tire

A tire comprising:

• a tread portion provided with a tread pattern,
• the tread pattern comprising a series of a number N of tread design units arranged repeatedly and circumferentially of the tire in a sequence,
• the tread design units having a number m (m=2, 3 or 5) of different circumferential lengths,
• wherein
• when
• viewing the tread design units as the number N of pulses, and
• defining a first pulse train such that the number N of the pulses are arranged in the same sequence as the tread design units at intervals which are defined by the circumferential lengths of the corresponding tread design units expressed in term of a ratio to one of said number m of different circumferential lengths,
• then
• a maximum value Pmax of amplitudes P(k) (k=order from 1 to 2N) of frequencies obtained by Fourier transforming said first pulse train with the following formula (1) is not more than 18.50-0.05N when m=2, 17.50-0.05N when m=3, and 15.00-0.05N when m=5,
• P
• 
• (
• k
• )
• =
• 100
• N
• 2
• 
• (
• a
• k
• 2
• +
• b
• k
• 2
• )
• 
• 
• a
• k
• =
• ∑
• j
• =
• 1
• N
• 
• sin
• (
• 2
• 
• π
• 
• 
• k
• l
• ·
• X
• 
• (
• j
• )
• )
• 
• 
• b
• k
• =
• ∑
• j
• =
• 1
• N
• 
• cos
• (
• 2
• 
• π
• 
• 
• k
• l
• ·
• X
• 
• (
• j
• )
• )
• (
• 1
• )
• wherein
• X(j) is the position of the j-th pulse from a beginning of the first pulse train, and
• l is a circumference length parameter equal to the sum of said ratios expressing the circumferential lengths of all the tread design units in said series,
• and
• the amplitudes P(k) and P(k+1) of every two of the adjacent orders (k) and (k+1) do not satisfy a condition that both of the amplitudes P(k) and P(k+1) have values of ⅔ or more times said maximum value Pmax.