Picked up a new Joplin 4 recently, (possibly should have know better with the mixed reviews the previous posts had) Its been used on two rides now (in the dry) and both times the seat refuses to stay up. It just sinks down over the space of a few minutes whilst on the saddle. Ive tried the pump method (hold remote pump seatpost down/repeat) no help.
Anybody had a similar issue, or can cast any light on fixing it?
Or am i calling 2Pure on moday morning for a warrenty in the first week of use 🙁

maybe an airlock in it???

Lil' Joplin may need a burping!!!

undo the gold collar and pump post up and down a few times, then tighten gold collar finger tight and see if that makes a difference.

If not as you say ring 2pure and see what they say and then let us know the answer.

If it's a cable remote it may be that the cable tension is too high and the button is being pressed all the time.

The problem I've had with mine is that when it's up it's fine but when I put it down it won't come back up again. I've sent it back (3 months old!)

I'll be getting a Rockshox one at the earliest opportunity!

Cheers for the quick response guys,

Valleydaddy just did as you suggested, and you know what, i 'think' its done the trick!! The post used to sink if i just bounced on the seat, and now it seems fine, no percievable sinkage! Il have to test it properly on tomorrow nights ride, but looks like the 'burping' did it!

Many thanks, STW to the rescue again. 🙂

il update the thread if all is well or if other issues arise.

this can happen if you "pull" the seat post up without using the leaver/remote to activate the return by all accounts, thus creating an airlock and stopping the post from fully extending back, and if you "pull" it up it will extend but drop down again if you get my meaning???

So "burp" and the problem is solved not ideal but works 😉

yep im pretty sure thats the cause (as my well meaning friend picked the bike up by the saddle, post-ride earlier this week)
Thanks for the tip to fix it, quick and easy after all. il know for the future,

thanks again 🙂

does it not need some air adding via the schraeder valve in the bottom of the post? What pressure should it be – anyone know?

gravity dropper all the way………

does it not need some air adding via the schraeder valve in the bottom of the post? What pressure should it be – anyone know?

That's a point that would help too.

No Idea what the pressure should be, no info on Crank Bros/2pure website either.

Hopefully someone will know RR

http://forums.mtbr.com/showthread.php?t=547214

mine was sluggish to return to its top height also…called Crank Bros…technician said 70psi on both sides of the valve…so using shock pump, pump it up to 70psi, activate valve which will equalize pressure…pump it to 70 psi again and activate valve again..repeat untill 70 psi is equal on both sides of the valve.

what a lot of faff……..

Thanks valleydaddy and RR il check what the pressure is. Cheers for the info!

Brilliant bit of kit but no good in the UK dirt and grime. 3 tips for anyone thinking of buying 1: 1. Buy the remote, infinite adjustment without looking away from the trail. 2. Buy some Lizard Skins neoprene suspension fork boots, cut one of them down and use it to protect the moving parts of the seatpost from dirt and grime – this will save you hours of maintenance and keep the seatpost functioning properly. In the UK it will need stripping and servicing after one wet and muddy ride. 3. Service the seatpost from time to time, don't waste money sending it away, just follow these instructions: Crankbrothers Joplin Oil Change *For just setting air charge – see below instructions Holding in remote lever or hand actuated lever, cycle post upside down several times. Let go of lever. Remove 10mm nut at bottom and unscrew Crankbrothers engraved collar. Remove outer tube. (Slides off) Remove micro Schrader valve cap at bottom of compression shaft (flat head screw driver). Cover Schrader valve with paper towel and release any pressure still in post. Remove Schrader valve core. With post right side up, aiming bottom valve into an oil bucket, release remote lever or squeeze hand lever. *This will release any pressure left and oil. Holding release lever in, cycle compression shaft (gold color bottom shaft) up and down, allowing oil to drip into oil bucket. *This will cycle out all the left over oil inside. At this point there should be no pressure and virtually no oil left in the post. Refilling post: Remove seat clamps from post and clamp head into smooth jaw vice, with compression shaft facing up, for easy filling. With a 60CC volume or more syringe (you can use smaller and just fill it several times) fill syringe to 55cc of 5wt or 10wt oil. *Oil weight does not matter but the volume does. Put plastic syringe tip into Schrader hole, slightly screwing it in to create a seal. Push oil into post at the same time releasing post lever. Cycle the compression shaft at the same time. *Your doing a couple of things at once here! The lever needs to be opened up, as well as being cycled, to allow oil into the lower chamber past the valve system and accept all 55cc of oil. Put a paper towel around bottom of syringe and Schrader valve to keep oil from spitting when pressure is release by removing syringe tip. *As you inject oil you build a small amount of air pressure. After all 55cc of oil is into post, install Schrader core (light torque). With standard shock pump pressurize to 70psi. Hit release lever, pump pressure will drop, pump back to 70psi and hit release lever. Continue to do this till it stays at 70psi when release lever is pushed. Remove pump. Reinstall micro cap, reverse installation of outer tube. *removal of outer tube in post instruction manual included with post. Cycle post several times with lever squeezed to activate valve system. Check for firmness at top and holding at bottom. If it continues to be squishy at top, more oil is needed, only 2 – 3CC max more is needed. Get post situated back into vice. Hold lever and cycle compression shaft 5+ times with release lever squeezed. This will be tough as you are pushing against high pressure. Undo micro Schrader valve cap, cover valve with paper towel and release pressure. Safety glasses on! DO NOT SQUEEZE LEVER FROM THIS POINT ON. Oil will shoot up if you do! Add 2 – 3CC of oil to Schrader hole. (Schrader core removed) Close up system, follow above procedure for this. This will do it! Go ride! Setting air pressure in Crankbrothers Joplin seat post: Holding in remote lever or hand actuated lever, cycle post upside down 5 -6 times. Let go of lever. Remove 10mm nut at bottom and unscrew Crankbrothers engraved collar. Remove outer tube. (Slide off) Remover micro Schrader valve cap at bottom of compression shaft (flat head screw driver). Cover Schrader valve with paper towel, Face Upwards, push Schrader valve to release any pressure still in post. Remove seat clamps from post and clamp head into smooth jaw vice, with compression shaft facing up, for easy filling. With standard bicycle shock pump, pressurize Schrader valve to 70psi. Max pressure = 75Ppsi. Leave pump on post. Hit release lever, pump pressure will drop. Pump back to 70psi and hit release lever. Continue to do this till it stays at 70psi when release lever is pushed. Remove pump. Reinstall micro Schrader cap. Grease glide rings and guide block & install outer tube Tighten 10mm nut at bottom to 40in/lb Tighten Maverick seal head collar, hand tighten, over tightening this will slow the post down by crushing to rubber seal. Cycle post several times with lever squeezed to activate valve system. Check for firmness at top and holding at bottom. Done! Go ride!