The traditional drum track is with solid structure. It is very heavy, weighting about 250kgs. And it will be bigger when the concrete mixer drum capacity is larger. Because the track with solid structure is lack of the deformability, the welded track onto the drum often snaps when using for some time. If only reducing the sectional dimension of the track ring to reduce its weight, the rigidity of the track will be decreased a lot that it cannot bear the weight of the drum. So it is a big challenge for the engineer to reduce the weight of the drum track.
