An investigation has been carried out in order to "nd how the kinetic energy of seeds sliding and falling down a seed tube was in#uenced by tube diameter, inclination of the tube and radius of coulter bend in a simulation of a tube and coulter system. The kinetic coe$cient of friction found by elevating the tube until the seed velocity was constant was only valid for tube inclinations up to 253. At higher tube inclinations, the coe$cient of kinetic friction had to be replaced with a new apparent coe$cient of friction with a higher value. Ideally, the delivery tube leading to the bend should be inclined at 603 to the horizontal plane. Delivery tubes at inclinations of 903 and 453 were tested in the laboratory. The results showed that the seeds lose a considerable kinetic energy when running through a 903 bend. Seeds dropped in a vertical tube or into a bend of small radius, lost almost all their kinetic energy when colliding with the horizontal or low inclination part of the bend. To lower the impact of collisions in the bend, the ratio of the bend radius to the tube diameter should be as large as possible. Tube diameter had no in#uence on the energy loss when the delivery tube was inclined to 453. Inclined tubes into the bend were favourable, because collision energy was minimized. The results of this investigation were used in designing a new seed tube and coulter assembly for direct drilling.