possess no rotational symmetry and exist at much lower Reynolds numbers. Particularly striking is an 'asymmetric mode' which has one slow streak sandwiched between two fast streaks located preferentially to one side of the pipe. This family originates in a pitchfork bifurcation from a mirror-symmetric travelling wave which can be traced down to a Reynolds number of 773. Helical and non-helical rotating waves are also found emphasizing the richness of phase space even at these very low Reynolds numbers. The delay in Reynolds number from when the laminar state ceases to be a global attractor to turbulent transition is then even larger than previously thought.PACS numbers: 47.20.Ft,47.27.Cn,47.27.nf Wall-bounded shear flows are of tremendous practical importance yet their transition to turbulence is still poorly understood. The oldest and most famous example is the stability of flow along a straight pipe of circular cross-section first studied over 120 years ago [1]. A steady, unidirectional, laminar solution -HagenPoiseuille flow [2, 3] -always exists but is only realised experimentally for lower flow rates (measured by the Reynolds number Re = U D/ν, where U is the mean axial flow speed, D is the pipe diameter and ν is the fluid's kinematic viscosity). At higher Re, the fluid selects a state which is immediately spatially and temporally complex rather than adopting a sequence of intermediate states of gradually decreasing symmetry. The exact transition Reynolds number Re t depends sensitively on the shape and amplitude of the disturbance present and therefore varies across experiments with quoted values typically ranging from 2300 down to a more recent estimate of 1750 ([4, 5, 6, 7, 8, 9, 10, 11, 12]). A new direction in rationalising this abrupt transition revolves around identifying alternative solutions (beyond the laminar state) to the governing Navier-Stokes equations. These have only recently be found in the form of travelling waves (TWs) [13,14] and all seem to be saddle points in phase space. They appear though saddle node bifurcations with the lowest found at Re = 1251. The delay before transition occurs (Re t ≥ 1750) is attributed to the need for phase space to become sufficiently complicated (through the entanglement of stable and unstable manifolds of an increasing number of saddle points) to support turbulent trajectories.In this Letter, we present four new families of 'asymmetric', 'mirror-symmetric', helical and non-helical rotating TWs which have different structure to known solutions and exist at lower Reynolds numbers. The asymmetric family, which have one slow streak sandwiched between two fast streaks located preferentially to one side of the pipe, are particularly significant as they are the missing family of rotationally-asymmetric waves not found in [13,14] and have the structure preferred by the linear transient growth mechanism [15]. They bifurcate from a new mirror-symmetric family which can be traced down to a saddle node bifurcation at Re = 773. This figure substantially lowers the ...