A component set, which contains crossmembers, which are intended to support rectangular solar modules, and holders for attaching the crossmembers on traverses, which are mounted at a slant on a roof and cross the crossmembers at a right angle, having the following features: - The holders have a plate as the base body, on which two parallel ribs (30, 31) are provided; - both ribs (30, 31) are provided with undercuts in order to form a channel (30a, 31 a); - the undercuts of the two ribs (30, 31) are identically oriented; - a groove is provided in the plate, next to one of the ribs (30, 31), but not between the ribs (30, 31), said groove extending parallel to the ribs (30, 31); - the groove is designed to be undercut on both sides; - a spring is inserted into the groove, which is held in the groove by the undercuts and protrudes beyond the outer edges of the groove; - the holder has means for connecting the holder to a traverse; - the crossmembers have a web, which connects two walls (39, 40) extending at a right angle to the web; - a first one of the two walls (39, 40) carries two strips (41, 42), which are parallel to the first wall, on the side of said first wall that faces away from the other, second wall, said strips fitting underneath the two undercut ribs (30, 31) of the holder; - the profiled shape and the dimensions of the crossmember and the holder are matched to one another such that the spring must be pressed down into the undercut of the ribs in order to insert the two strips (41, 42), after which the spring expands again and locks the crossmember in the holder; characterized by the following features: - the spring has a section having the shape of a bridge arch, which protrudes beyond the outer edges of the groove; - the bridge arch-shaped section of the spring extends into two wider, flat end sections of the spring, by means of which the spring is held in the undercut groove; - the end sections of the spring have play, in order to glide in the groove in the longitudinal direction thereof when the bridge arch-shaped section of the spring is pressed down, - The holders have a plate as the base body, on which two parallel ribs (30, 31) are provided; - both ribs (30, 31) are provided with undercuts in order to form a channel (30a, 31 a); - the undercuts of the two ribs (30, 31) are identically oriented; - a groove is provided in the plate, next to one of the ribs (30, 31), but not between the ribs (30, 31), said groove extending parallel to the ribs (30, 31); - the groove is designed to be undercut on both sides; - a spring is inserted into the groove, which is held in the groove by the undercuts and protrudes beyond the outer edges of the groove; - the holder has means for connecting the holder to a traverse; - the crossmembers have a web, which connects two walls (39, 40) extending at a right angle to the web; - a first one of the two walls (39, 40) carries two strips (41, 42), which are parallel to the first wall, on the side of said first wall that faces away from the other, second wall, said strips fitting underneath the two undercut ribs (30, 31) of the holder; - the profiled shape and the dimensions of the crossmember and the holder are matched to one another such that the spring must be pressed down into the undercut of the ribs in order to insert the two strips (41, 42), after which the spring expands again and locks the crossmember in the holder; - the spring has a section having the shape of a bridge arch, which protrudes beyond the outer edges of the groove; - the bridge arch-shaped section of the spring extends into two wider, flat end sections of the spring, by means of which the spring is held in the undercut groove; - the end sections of the spring have play, in order to glide in the groove in the longitudinal direction thereof when the bridge arch-shaped section of the spring is pressed down,