Rase use pretty basic engineering executed to high quality, and with a massive 228.6mm (9in) drop, the Black Mamba nearly doubles anything else out there.
The slider shaft is supported by a small diameter coil spring that’s extended as the post is lowered. A sprung pin locks the post in place through 20 individual drilled stops along the range of adjustment.
The rapid return is undamped, but the light spring means it’s not an issue. Maximum extension is adjustable to fit individual requirements, but a straight seat tube is needed to accommodate the internals as the post drops.
There is some play in all directions when the post is new, but so far, careful maintenance has ensured that this hasn’t worsened.
To initiate lowering of the post you must fully unweight it, pull the superb mini-lever, sit down until the saddle reaches your desired height and then release the lever. The post slides smoothly enough, although it’s clunky when it locks into place, and regular cleaning and lubing is required to keep it smooth.
The optional neoprene sleeve is essential, because the design is very open and won’t last seconds in mud. It is a bit agricultural, heavy at 667g and not the easiest to use, but it does work, and it drops an awful long way.