Crank Brothers Joplin 4 seatpost – loses air pressure.

Had my Joplin 4 seatpost serviced about 15-18 months ago, always keep a lizard skin over it and give it good clean and regrease every now and then.

Just recently I went to use my bike and the seatpost has lost all air pressure. Tried adding some air again which lasted half a ride but now all air has been lost again.

Does anyone know how to fix this? Found a service kit fot the external seals and bushes but nothing seems to be available for the internals!

Any help would be appreciated.

I had a Joplin 3 that did this. Tried servicing the internals but in the end it turned out to be the tiny O ring that seals round the actuator pin under the seat. It was a faff but I managed to make a tool to strip it down completely and get the top end cleaned and greased Certainly made a difference but I moved on to a KS LEV fairly quickly afterwards

mine is also doing this, I threw it in a box and forgot about it, really need to investigate….

the cheapest and quickest way to fix this is to buy a more reliable post.

Rockshox or thomson

I’ll echo connect2s reply, it’ll be the I ring on the actuator pin. Very difficult to get out without the proper tool ( which you can’t buy . I’ve made one and still can’t get it out.

Other than buying a better one, you have the option to send it back service or live with it and pull it up by hand. I changed mine from remote to under saddle lever and just pull it up by hand, although it’s only on my hack bike now as I bought a Thomson instead.

I’ll echo connect2s reply, it’ll be the I ring on the actuator pin. Very difficult to get out without the proper tool ( which you can’t buy

^ Yep agreed. 2 x Joplin 3 here sitting in boxes waiting to be sold for spares. Ive KS droppers now

That should read o ring, and not I ring !

same here and yeah it’s the o ring at the top, after I had it repaired under warrantly (after about 5 rides!) they included a note saying to keep the top of the post clean and not let dirt get in.

Thanks guys, looks like it is quite a common problem. Been considering a rock show reverb but as its £40 to get mine serviced it’s still quite a bit cheaper than buying a new seat post!

Just looked at my receipt from the last service and that’s dated March 2013, so in the scheme of things I haven’t actually done that bad with how much use I have had from it.

The shortlist for a new seat post are the KS and Reverb.

Anyone got any experiences with the Reverb?

reverb is fantastic