I had a slow motion crash in the mud on Monday, resulting in grazed knees and a dropper post that won't stay up or down. I've tried pumping air into it and I've had it out to make sure the cable's working properly.
When I press it down you can hear air whistling out of the bottom. Is it completely borked or can I fix it?
What brand?
KS Lev.
Sounds like the cable is jamming. Have you tried disconnecting the cable? Does it then lock in place? External or internal routing? I've repaired an older KS post and it was pretty similar to a Reverb internally IIRC, although an utter ballache to pressurise. The later one was a cartridge.
The cable is be running freely and pulling the switch at bottom. It’s internally routed.
So with the cable completely disconnected, what happens?
You can push it easily in either direction and it isn’t locked up or down.
Fixing a dropper is dependant on a few things.
Is the post designed to be repairable. Sounds silly, but one-up and brand-x are not because they use a sealed hydraulic cartridge. The Thomson isn't because they need specialist tools and there's no spares availability.
I've found the best for repairability are reverb, which needs it regularly. The most repairable is the BikeYoke that ironically seems to need the least attention.
I used to run a couple of externally routed KS Lev's and they were fairly straightforward to work on. This was pre Brexit and spares could be had easily from German sites. No idea what spares availability is like now though.
Hmm, doesn’t sound like it’s an easy fix then. I’d much rather repair and re-use but it looks like it’s easier to just buy a £50 replacement from Wiggle.
If you can get a new brand x for £50 then it’s probably a no brainer.
On the comment above that one up / brand x aren’t designed to be fixed I guess that’s related to the sealed cartridge inside. But I believe you can buy a spare cartridge to swap in for broken ones to keep the posts going. Normally that’s economically worth it - but less so when new posts are being sold for £50!
If you can get a new brand x for £50 then it’s probably a no brainer.
If you're a short arse with either a 30.9 or 31.6mm seat-tube then yes you can get a 357x100mm dropper for £49.99 if you're not a midget it's only £99.99 for a longer one.
If it was myself, I'd go for the £50 replacement to keep the bike running. Then I'd find some service vids on YouTube, depressurise it and try to fix it.
It's hard to think how it's failed in a crash, unless the cartridge or IFP (depending on the mechanism) has failed from the saddle being pulled up with the dropper in the down position.
I'd give the lev a basic service before condemning it. It's no harder than doing an air can on a shock, and could resolve little things like something stuck in the actuator mechanism.
There's an operating rod that runs from the (screw on) base, up through the centre of the post. These caused a lot of similar problems in the past (because they were fractionally too long), so it may be worth pulling it out, and checking it's not sticking or damaged. It only takes a few minutes, so has to be worth a try.
