Aside from wide tires with little air pressure, suspension seat posts are a simple and, by comparison, cheap option to upgrade the bike for more comfort. It's the reason why suspension posts are preferably used on trekking and touring bicycles. Their benefit lies in the impact absorption to protect the biker's back as our mostly upright sitting position makes it difficult for the body to absorb shocks. There are two design types for suspension seat posts: Telescopic posts and parallelogram seat posts. Telescopic seatpostsare optically less obtrusive, usually lightweight and more affordable. However, the direction of the spring compression isn't ideal for absorbing impacts to the rear wheel. Furthermore, the saddle height changes during compression. Suspension seat posts with a parallelogram system allow for more suspension comfort since the spring movement is directed towards the impact. Because the distance from the saddle to the pedals doesn't change much during compression, an extended suspension travel is principally possible. However, the seat post head usually has a rearward offset, which doesn't align with some sitting positions. What needs to be considered is that both variants not only have minimum insertion depth, but also a minimum pullout. Slide bushings or parallelogram system cannot be lowered into the seat tube. The seat tube's inner diameter is less problematic and adapter sleeves are also available for less common measurements.