Dropper post problem - Crank Brothers

[Hobo Mikey]

Down the bike park a couple of days ago, went to put dropper post down and would not go down even with my fat arse and 15 stone sat on it.
stopped and tried to push it down but no go, sat back on the saddle and if I sit on front of saddle it goes down but not if I sit where I should be, same if I stand next to it and push on front of saddle goes down but push on rear no go.
Any ideas before I take it to LBS

 

[RustyIron]

It sounds as if it's binding. That can happen when it's excessively worn or if it's in need of lubrication. Servicing at regular intervals can minimize this. Whip a little service on it and replace anything that is worn out. The make and model of the seatpost might be a consideration when deciding what to do.

 

[theremotejuggernaut]

What post is it?

Go on, give us a clue!

The standard Orange post on my Crush used to do exactly this when it got wet.

That was down to water getting inside and causing it to lock up.

Unscrewing the collar and leaving it upsdoe down overnight used to sort it out.

The OneUp post on my Rise was getting sticky recently. It sometimes wouldn't drop unless my weight was in exactly the right place. It took about half an hour to remove, strip, clean and grease the internals and refit it to the bike.

Could also be cable tension? (unless Reverb) have you got excessive/ floppy lever travel?

 

[irie]

Down the bike park a couple of days ago, went to put dropper post down and would not go down even with my fat arse and 15 stone sat on it.
stopped and tried to push it down but no go, sat back on the saddle and if I sit on front of saddle it goes down but not if I sit where I should be, same if I stand next to it and push on front of saddle goes down but push on rear no go.
Any ideas before I take it to LBS

If you tell us what make and model it is you'll probably get targeted help with it.

 

[Hobo Mikey]

Sorry forgot that bit, it’s a crank brothers On a Whyte E150 RS

 

[theremotejuggernaut]

No experience of that particular post but looks super easy to service according to this

NSMB.com - Crankbrothers Highline Dropper : Teardown

My view on stuff like this...

if its already fucked, you're not going to make it worse by trying to fix it

 

[The EMF]

You can get a refresh kit for your seat post from Bikeinn……cheap and fast delivery and it’s an easy service job

 

[ilostmypassword]

Every Crank Brothers product i've owned failed. I recommend avoiding them.

 

[Dax]

Pull it out the frame and check it's actuating the post when you press the lever

 

[B1rdie]

Lube the bushing soon, before it wears and needs replacement…

 

[The Hodge]

Lube the bushing soon, before it wears and needs replacement…

Fork Juice ..by Juice Lubes ..swear by that stuff for forks , shock & seat posts ..online for about a tenner ..( + postage )

 

[RustyMTB]

They're much of a muchness usually, a cartridge which does the up & down bit & a shaft that slides inside an outer sleeve. If they go wrong it's often one or other of the bushings that's gone. Quite often they have three or four soft brass or similar material bushings that sit in recesses in the inner sleeve & collar bushes to keep dirt out & lube in. So it's a disassembly job to get at the bits or give it to the LBS if you can't be bothered with all that messsing abut with spanners.

 

[steve_sordy]

The seat post is full of finely machined components and they don't like being squeezed by the seat post clamp being too tight. To reduce the clamping force but still give an effective clamping action, use any assembly gel designed for carbon fibre components. You can use it on ally components as well, it works just the same.

I use Finish Line Fiber Grip - Carbon Fiber Assembly Gel. I got mine from CRC but lots of places do it.

Finish Line Fiber Grip 50ml Carbon Fibre Assembly Gel

I just noticed that Halfords have a version for £3 that may be worth trying.

Halfords Carbon Gripper Paste 10g | Halfords UK

Shop the latest Halfords Carbon Gripper Paste 10g at Halfords UK

www.halfords.com

 

[steve_sordy]

If your Crank Bros dropper proves to be beyond repair, then don't go replacing it with another expensive one! Do yourself a favour and consider the really great versions by Brand-X, available from CRC. They have lots of diameters and drops.

https://www.chainreactioncycles.com/brand-x

Choose which type of dropper and go to the pictures at the top of the page. Then page right until you get to the dimensioned drawing (page 7 I think). That will allow you to ensure that you are choosing the correct post for your bike.

Currently, all their Brand-X droppers are £90 except the XL versions (170 & 200mm drop) which are £150.

 

[RustyMTB]

My bike came with a KS something or other. I looked up the service video from KS when it started playing up which instructed me amongst other things, to take a Coke can & cut it up with scissors in order to create a thin wedge of aluminium that would be used to slide a collar bush over the inner sleeve. At that point, I threw it in the bin & bought a Brand X.

 

[Hobo Mikey]

Dropping it excuse the pun off tomorrow to LBS for them to investigate. Will let you know the outcome as soon as I know.

 

[B1rdie]

My bike came with a KS something or other. I looked up the service video from KS when it started playing up which instructed me amongst other things, to take a Coke can & cut it up with scissors in order to create a thin wedge of aluminium that would be used to slide a collar bush over the inner sleeve. At that point, I threw it in the bin & bought a Brand X.

Yep, trying to fix the air cartridge of a KS can be a PITA, but they now offer the full kit on ebay for $80 and instaling it is not that bad. I have started to use KS branded droppers in 2014, and still have them on four bikes. The cube came with a tranzX and its been working very well.

 

[RustyIron]

Sorry forgot that bit, it’s a crank brothers On a Whyte E150 RS

In years past I've used a lot of Crank Brothers components, and they were always really good about warranty repairs. I don't know where Where Ever is, but if it's close to Laguna Beach, just pop on in and ask them to fix it up for you.

 

[Hobo Mikey]

In years past I've used a lot of Crank Brothers components, and they were always really good about warranty repairs. I don't know where Where Ever is, but if it's close to Laguna Beach, just pop on in and ask them to fix it up for you.

I wish I was there but I am in the U.K. but I live in a camper van so travel around for work, hence the title wherever.

 

[GodsHammer]

Hi All

I had this seat post and it did the same thing in fact went through 2 off them, (Wiggle exchanged them) the cable would snag and never how hard I tried could not get it to work. Went to a hydraulic one no issues at all. hoped this helps.

Have a good un and keep smiling Nick

Norfolk 3 toed bog plodder.