I mumped and moaned at the poor performance off this post, it wouldn’t drop or rise consistently. So I took the saddle off to see if anything had got jammed under the lever and found that it worked okay. What was happening, was that the lever couldn’t be pulled up far enough to release the mechanism because of the plastic cover under the front of my SDG Bel Air.
Swapped saddles – perfectly working seatpost and no mumping.
Hope this helps.

Odd, cos I’ve got the same combo on one of my bikes, and never had a problem with it!

Could be an angle of seat, angle of seat tube thing or just a tolerance thing with my post.

Hey ho, it works now and I can get it up(or down) with just a gentle squeeze between my legs (ooh missus)