This seat post is suitable for, among others, VanMoof S/X and other bicycles with a seat tube diameter of 34.0mm. Seat post diameter: 34.0mm Seat post length: 400mm Primax E seat post SP90 34.0 x 400mm black. Suitable for, among others, VanMoof S/X and other bicycles with a seat tube diameter of 34.0mm. Tip: Apply some grease to the seat post before assembly. The seat post must be inserted far enough into the seat tube; the minimum insertion mark must not be visible. Make sure to sufficiently tighten the seat post clamp bolt and saddle rail bolts afterward. If you want to adjust the height slightly afterward, loosen the seat post clamp bolt sufficiently to prevent scratches.