Replacing the pen is actually quite simple:
On the tube the seatpost fully unscrew -The spring rate-adjusting, note the correct position of the "spring guides".
Refer -The original spring and remove the shrink tube with 28mm standoff as a nut.
Unscrew -the shrinkable tubing of hard spring and screw the hose to the 28mm spacer.
Now introduce -The hard spring with the spring guides into the tube of the seat post and screw in the adjusting screw.
At the original spring was some fat was during the hard spring supplied virtually dry.
Therefore, the hard spring of me was neat greased with a good bearing grease.
Has so far only a few short laps test drive, but the hard spring or the seatpost work as far as I can tell so far very good.
Should this change, I will adjust the review accordingly.