a position in which it can move out of engagement with the clutch inner and outer races the faces 20 or 21 on opposite sides of each bar 18 intersect one another and also the face 15 or 16 on the same side of the bar all the bars being of uniform cross sectional shape and dimensions throughout their lengthwise portions 18 39 and 18 34 which portions are symmetrical about radial planes through the lines of intersection of their faces 20 or 21 this configuration of the bars 18 enables the retainer to be formed in two identical annular parts 14a one of which is shown in fig3 and 4 thus each bar 18 has two endwise abutting parts 18a and 18b respectively one on each of the parts 14a each longer part 18a has a lengthwise portion 18a 39 at its free end generally of the same cross sectional shape as the lengthwise portions 18 39 and 18 34 but the faces of which are inset with respect to the corresponding faces of the portions 18 39 and 18 34 by an amount which is a little greater than the thickness of a spring metal strip mounted on the portion 18a 39 and forming a sprag energising spring 24 see also fig7 and 8 the axial length of each porton 18a 39 is equal.