in use because of the centrifugal force to which the steel cylinder 35 is subjected the compressive stresses are reduced the thermal expansion coefficient of the cylinder material is much greater than the thermal expansion coefficient of the carbon fibre reinforced plastics material in the direction of the reinforcement fibres for example the thermal expansion coefficient u03b1 of steel is between 11 u00d7 10 u2212 6 1 k and 17 u00d7 10 u2212 6 1 k and that of cfrp in the fibre direction is about zero especially between u2212 2 u00d7 10 u2212 6 1 k and 2 u00d7 10 u2212 6 1 k when subjected to heat in use the internal diameter of the cfrp sheath 36 accordingly changes only very slightly whereas the thermal expansion of the steel cylinder 35 is considerable the thermal expansion of the cfrp sheathed steel cylinder 35 is consequently less than the thermal expansion of a cylinder having an all steel wall a roller according to the invention comprising a metal cylinder and a composite fibre sheath is lighter in comparison to an all steel or all aluminium roller has a reduced mass inertia and exhibits linear thermal expansion which is adjustable down to negative values as a result of constructively arranged fibre orientation the advantages of the roller according to the invention in use which result from the properties of the material are for example substantially improved braking values savings in.