Adjustable Seatpost Review: Precision Cycling Components All Mountain Post (A.M.P) vs. Crank Brothers Joplin-R Adjustable Seat Post

Adjustable Seatpost Review

Time for an adjustable seatpost review! A buddy and I both spent a couple of years riding Crank Brothers Joplin R posts, then switched to Precision Cycling Components A.M.P posts for a few months. Here are my thoughts on both posts:

Crank Brothers Joplin-R (R for remote) is a hydraulic adjustable seat post with 3” of travel and infinite adjustability.   It has a set-back Bontrager style clamp and an “actuating lever” than can be pressed in any direction.

Crank Brothers Joplin-R


  • You can drop the post easily at any time.  You can make a last minute decision, press the level, push it down with your butt, leg, stomach, or whatever else is on the saddle at that point, and release the lever.  Wherever it is when you release it, that’s where it will stay.  Then, when you want to raise it back up, just push the lever and it will return to full height.  It’s that simple…. most of the time.
  • Using the post is very intuitive.
  • What I think of what how an adjustable seatpost should work, the Joplin-R is what comes to mind.


  • The post will develop play such that the saddle will twist a few mm, side to side.
  • The hydraulic chamber can loose pressure.  Sometimes you can “pump” the saddle up and down and that will re-pressurize the chamber.  Other times it will require sending the post back to Crank Bros to be serviced.
  • The clamp.  Oh, the clamp.  No matter how hard I cranked down the saddle clamp I was still able to hit the tail of the saddle causing the nose to pop up into the air.  Needless to say it’s sub-optimal to sit back down when that happens.  Ultimately I had my local shop replace the internals with that from a new Bontrager post (same clamp) and that did the trick.  But I have heard from many buddies who have had issues with the clamp.  As you can imagine, having the nose of the saddle pointed up part way through the Downieville course is less than ideal.

Precision Cycling Components All Mountain Post

PC offers a few different versions of the AMP adjustable seatpost.  1”-3”, 1”-4”, and 2”-5”.  Own the 1”-4” version which means that it can be locked into full height, 1” down, or 4” down.   The clamp is not offset.


  • The A.M.P is an entirely mechanical adjustable post relying on springs to control the height of the post.  Therefore it works as well at altitude as it does at sea level.  And does fine when you drive between the two.
  • It springs up powerfully, but not too hard.
  • The 1” down riding position is fantastic.  80% of the time that I drop my post I drop it into the 1” down position.  It’s ideal for fast, slightly downhill singletrack where I want a bit more maneuverability and margin for error with my riding.
  • Less side to side slop.  That was a huge issue with my Joplin and has not proven to be a problem with this post.  That said, I only have a few hundred miles on the post and I’m starting to get a bit of side to side slop, but nothing like I got on my Joplin.
  • Great saddle clamp.  No chance of slippage, which was an issue with my Joplin.


  • When I do need my post to be all the way down (rock gardens, drops, screaming fast descents, etc), it doesn’t always stay down.
  • It’s also much harder to get it to say all the way down in a panic.  You have to press the lever, push the post down, the release the lever and hope it catches.  If you’ve twisted the saddle when pushing it down or didn’t quite get it far enough down it will shoot back up as soon as you take your weight off of it, which hasn’t contributed to a crash yet, but did have me puckered up on a few occasions.
  • Getting the post into the locked positions takes a bit more getting used to. You release the lever, then the post stops moving up and down when it finds its locked position.  That means that to get into the 1” position you release the post with the lever, push it down to the 1” position and it will lock in place.  Or more likely you’ll push it past 1”, then let it come back up until it catches.  It took me several rides to get used to that, but now its second nature.
  • This post is only made in 27.2, so you have to use a shim (which they provide).  I put that as a con because on the 3 posts I’ve seen in every case we had to use light sandpaper on the post and the inside of the shim to keep them from slipping.

Final Assessment:

Bill switched back to his Joplin once he got it back from the shop.  I’m going to leave the AMP on my single speed since I really only use it at full height and 1” down on that bike, and I’m rarely in a situation on the single speed where I absolutely want my post all the way down (rock garden / big huck).  But I plan on replacing the one on my Ibis Mojo (5.5” of travel) as soon as I can get a Joplin 4.  The fact that the A.M.P doesn’t always lock into position on the first try drives me nuts.

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