Originally Posted by
SoSmellyAir
OP only has 2.5" of exposed seat post; not sure there is enough length for the mechanisms of the latter two posts. Also not sure that the Specialized CG-R can be clamped that close the dampener, if it fits at all.
You would be right. Checked my Cirrus body float seat post and it is around 4.25" from seat rail to the post itself.
Don't know what sort of bike fit the OP has got that his seat post is so short.