Dropper post - Very rough travel

[Craig Armstrong]

I just bought my first bike with a dropper post and shipped it from Cape Town to Johannesburg.

 

When it was in Cape Town, the dropper worked perfectly and smoothly.

 

When it arrived in Joburg, the dropper had no air in it. 

After pumping it up, it goes like this:

 

https://streamable.com/s/v5kpy/jlwdc

 

You can hear and feel that the bearings are very rough (Or at least it seems like bearings).

 

I've read some things online since unpacking the bike saying that you can break your dropper post by keeping it in the 'down' position for too long. It seems unlikely that that could have caused symptoms like this though.

 

What do you guys reckon? 

[Headshot]

What brand of dropper is it? Is it new?

[Craig Armstrong]

What brand of dropper is it? Is it new?

 

Its not new. Got the bike second hand. 

Its a Specialized command post

[Headshot]

I have one. They are noisier than most because of the mechanical system used to lock the post in place. They are also quite serviceable I believe. Ensure that your lever and cable have no slop. If they do it might cause the mechanism not to disengage fully causing the noise when the post moves.

[Craig Armstrong]

I have one. They are noisier than most because of the mechanical system used to lock the post in place. They are also quite serviceable I believe. Ensure that your lever and cable have no slop. If they do it might cause the mechanism not to disengage fully causing the noise when the post moves.

 

Hmm okay, I'll give that a shot. Any tips to make sure there's no slop in the cable? Never had a dropper before

[Craig Armstrong]

If you push the seat all the way down and then bring it up from there, the travel is smooth until like half way up the post. It reaches a mid point where it clicks into place, and then the travel from there until fully extended is very rough. It feels like theres notches in the travel

[ABrooks]

The command posts have preset height settings, I think it is about 12 different heights. I went from a Lyne dropper to a Command post and it was something to get used to in terms of feel and sound, but now I don't even think about it any more. Mine doesn't sound like that though.

 

To how much psi did you pump it?

[Craig Armstrong]

The command posts have preset height settings, I think it is about 12 different heights. I went from a Lyne dropper to a Command post and it was something to get used to in terms of feel and sound, but now I don't even think about it any more. Mine doesn't sound like that though.

 

To how much psi did you pump it?

 

Okay that makes sense. So the notches I'm feeling are the different height settings. 

After pumping it higher, it now travels a lot more like I think it should.

25 psi was where I could get it to travel the full distance without getting caught near the top. I think 20 psi is the recommended? 

 

I'm thinking that Headshot might be onto something when he says I should pick up the slack in the cable. Maybe its not fully disengaging, because I can feel it getting caught on each of those height steps as it travels.

 

Now the issue is that I don't have a cable cutter. Guess I gotta go to a bike shop for this one

[ABrooks]

Okay that makes sense. So the notches I'm feeling are the different height settings.

After pumping it higher, it now travels a lot more like I think it should.

25 psi was where I could get it to travel the full distance without getting caught near the top. I think 20 psi is the recommended?

 

I'm thinking that Headshot might be onto something when he says I should pick up the slack in the cable. Maybe its not fully disengaging, because I can feel it getting caught on each of those height steps as it travels.

 

Now the issue is that I don't have a cable cutter. Guess I gotta go to a bike shop for this one

I think the max is 40psi so just don't go over. Mine sits at around 30 I think, thats about where the shock pump starts to have readings.

 

If you want to cut the cable without a cable cutter you can wrap the cable in some electrical tape and use a dremel if you have one, that is what I do and have never had a cable fray on me.

[Dirt Tracker]

If it's a Command post IIRC then they make alot of noise at the middle of the travel where they have 10 or so preset heights. It kind of sounds like a cable tie being tighten quickly. I freaked out when I got mine as I was also coming off Lyne that was just up and just down. The Spez ones seem to hit different heights depending on how much you press the lever in. All good though as soon as I started riding I never even noticed. Now I'm just glad that it seems bombproof, like that you can pump it a bit, doesn't have any side to side play and doesn't look too hard to service.

 

Also those things are lethal if you over pump them. My LBS over pumped mine and I pressed the lever and it shot up so hard it actually pulled it's self out of the done up seat post clamp.   There is a video or two floating about of them being use to launch tennis balls for dogs to go chase. 

[ABrooks]

There should be a barrel adjuster at the lever, see if you can take up the slop in the cable with it before cutting.

[Craig Armstrong]

If it's a Command post IIRC then they make alot of noise at the middle of the travel where they have 10 or so preset heights. It kind of sounds like a cable tie being tighten quickly. I freaked out when I got mine as I was also coming off Lyne that was just up and just down. The Spez ones seem to hit different heights depending on how much you press the lever in. All good though as soon as I started riding I never even noticed. Now I'm just glad that it seems bombproof, like that you can pump it a bit, doesn't have any side to side play and doesn't look too hard to service.

 

Also those things are lethal if you over pump them. My LBS over pumped mine and I pressed the lever and it shot up so hard it actually pulled it's self out of the done up seat post clamp.   There is a video or two floating about of them being use to launch tennis balls for dogs to go chase. 

 

I actually used the comparison to a cable tie when I described the sound to a friend!

Okay so I think I can safely ignore it then, and everything is probably functioning normally.

 

Note that its not still behaving like in my original video (travelling slowly). It now comes up quicker, but you can just hear those notches as it comes up (Sounds like a cable tie, as you described).

 

Just didn't want to leave it like that and find out later that I'm wearing something out by letting it run like that. 

I thought maybe its not disengaging like its supposed to, so its hitting those notches when its supposed to just glide over them.

 

But from your guys experiences, everything seems to be working as intended.

 

Thanks

[Dirt Tracker]

I actually used the comparison to a cable tie when I described the sound to a friend!

Okay so I think I can safely ignore it then, and everything is probably functioning normally.

 

Note that its not still behaving like in my original video (travelling slowly). It now comes up quicker, but you can just hear those notches as it comes up (Sounds like a cable tie, as you described).

 

Just didn't want to leave it like that and find out later that I'm wearing something out by letting it run like that. 

I thought maybe its not disengaging like its supposed to, so its hitting those notches when its supposed to just glide over them.

 

But from your guys experiences, everything seems to be working as intended.

 

Thanks

 

Might be worth a quick service. Like any suspension part, if it's second hand I get it serviced asap. Going up slowly is usually an air thing. Pump it up a bit with a shock pump under the seat and see how you go. Maybe it you can pull it out then you can empty the all the air and go from scratch. 

[Headshot]

I actually used the comparison to a cable tie when I described the sound to a friend!

Okay so I think I can safely ignore it then, and everything is probably functioning normally.

 

Note that its not still behaving like in my original video (travelling slowly). It now comes up quicker, but you can just hear those notches as it comes up (Sounds like a cable tie, as you described).

 

Just didn't want to leave it like that and find out later that I'm wearing something out by letting it run like that. 

I thought maybe its not disengaging like its supposed to, so its hitting those notches when its supposed to just glide over them.

 

But from your guys experiences, everything seems to be working as intended.

 

Thanks

I agree with DT - have it looked at if adjusting the cable doesnt get rid of the noise. My Command Post 125mm is running at 20psi and rises with speed at that pressure. There is no mechanical noise as it rises. The only time you hear the noise is when adjusting the post to the desired position in the last half of its travel. Its a very good seat post IMO so it would be a pity if you don't get the most out of it...