I used a simple / very favorable steel suspension (right in the seat tube) - when I honestly felt no difference to an unsprung seat tube. (The spring rate is adjusted via an adjusting screw down the seat tube which - In this Suntour parallelogram the whole thing is completely different - the suspension works 1a (a little adjustment work is already needed - I had the seat ca solve 3-4 times repeatedly and pull out tube steel spring is either loose or stretched) Super sub -. the gross as well as the smaller bumps are very well cushioned (is also in one of the wheel test-covers on magazines price / value for money - exceptional I thought the test - and was not disappointed). Replacement / Exchange is quick and easy. The installation instructions are included too, and is designed in detail. There is also the work areas of the suspension (the supplied steel spring is to 95 kg designed). I weigh about 92kg and find this on Parallegramm suspension seatpost a useful addition to my bike with a rigid fork. Would definitely buy again. What could make Suntour little better (see, eg pepper-bikes) - einläsern a measuring scale or 'paint on' the tube is completely black - and only the minimum installation depth is clearly marked.