Store bike with dropper post compressed

[Tokyo]

Want to hang my bike as high as possible is it bad to store bike with dropper post compressed? 

[Headshot]

I suggest you check the manufacturers website for your dropper. Specialized command post droppers rely on the stanchion to be in perfect condition in order to  keep the airs pring sealed and they therefore recommend that you keep the seat in the down position to prevent it being damaged in storage or while racked on your car.

That said, I recall reading that droppers with sealed cartridges should be stored with the post extended. I can't really understand why as the cartridges are much like the gas struts that hold your boot or bonnet up and spend almost 100% of their lives compressed.

[BaGearA]

No problem at all

[guidodg]

no problem whatsoever..

[MORNE]

funny, i was wondering this exact thing last week as i have a similar issue in storage. I googled it a few times and it differs between brands. I have a Bikeyoke Revive on mine and the manual says it's all good to store in the down position...ideally even 50% compressed. It has an air cartridge for what its worth.

Apparently its a bit iffy to do this with hydraulic ones like the Rockshox as it places too much pressure on the seals. But generally it seams ok to do with air ones from what i've read.

One common theme I picked up was to not pull or pick your bike up by the saddle once a dropper is compressed. I avoid it generally but i see this a lot at trail heads where people have their bikes hanging from saddles on those racks with the saddle down. Luckily my bikes are too big and saddle usually too high to even use those things in any case haha

[lechatnoir]

1 hour ago, Headshot said:

I suggest you check the manufacturers website for your dropper. Specialized command post droppers rely on the stanchion to be in perfect condition in order to  keep the airs pring sealed and they therefore recommend that you keep the seat in the down position to prevent it being damaged in storage or while racked on your car.

That said, I recall reading that droppers with sealed cartridges should be stored with the post extended. I can't really understand why as the cartridges are much like the gas struts that hold your boot or bonnet up and spend almost 100% of their lives compressed.

had my hatchback boot lid fall on my head enough times to wonder why they fail...

[Zebra]

2 hours ago, Headshot said:

I suggest you check the manufacturers website for your dropper. Specialized command post droppers rely on the stanchion to be in perfect condition in order to  keep the airs pring sealed and they therefore recommend that you keep the seat in the down position to prevent it being damaged in storage or while racked on your car.

That said, I recall reading that droppers with sealed cartridges should be stored with the post extended. I can't really understand why as the cartridges are much like the gas struts that hold your boot or bonnet up and spend almost 100% of their lives compressed.

Are dropper posts not INVERSE to gas struts on say a SUV rear hatch…?
Reason I ask, is that in motorbikes, upside-down forks give the same (similar) suspension effect as right-way-up forks, but using a different principle (unsprung weight…)?

maybe THAT is why recommended to store them ‘extended’?

Dunno?!!!!!!

Edited October 28, 2022 by Zebra
Spelling

[droo]

4 hours ago, MORNE said:

Apparently its a bit iffy to do this with hydraulic ones like the Rockshox as it places too much pressure on the seals. But generally it seams ok to do with air ones from what i've read.

Revive is also hydraulic, it's just easier to get squish out. Both Reverb and Bikeyoke are easy enough to reinflate if they lose pressure. The ones you want to avoid storing compressed (if any) are the cartridge ones, cos once they go flat you replace the cartridge.

Quote

One common theme I picked up was to not pull or pick your bike up by the saddle once a dropper is compressed.

This is the important bit. If you pull a vacuum on the oil in the post it can boil off gas, which makes your dropper seatpost into a suspension seatpost.

Edited October 28, 2022 by droo
Spelling

[Jbr]

21 minutes ago, droo said:

Revive is also hydraulic, it's just easier to get squish out. Both Reverb and Bikeyoke are easy enough to reinflate if they lose pressure. The ones you want to avoid storing compressed (if any) are the cartridge ones, cos once they go flat you replace the cartridge.

This is the important bit. If you pull a vacuum on the oil in the post it can boil off gas, which makes your dropper seatpost into a suspension seatpost.

Thanks, I learnt two things in one post, and on a friday, what a day !

[madmarc]

After stripping my KS Lev cartridge numerous times and now knowing how they operate i would not store them in the compressed position for any long periods of time. When they are compressed the air pressure chamber pressure is increased exponentially and i would imagine this places the seal between the air and oil chamber under enormous strain.

The cartridge is made up of 2 chambers - inner chamber is the oil chamber with a piston rod - outer chamber is the air chamber - when you activate the lever it opens a valve in the end of the piston rod and with the weight of the rider it pushes the piston up into the oil chamber basically displacing the oil into the air chamber. The air and oil is separated by a sliding seal in the air chamber, so the air above the seal is compressed. Considering i pump mine to 200 psi i can imagine what the pressure would be when compressed.

[DieselnDust]

7 hours ago, Headshot said:

I suggest you check the manufacturers website for your dropper. Specialized command post droppers rely on the stanchion to be in perfect condition in order to  keep the airs pring sealed and they therefore recommend that you keep the seat in the down position to prevent it being damaged in storage or while racked on your car.

That said, I recall reading that droppers with sealed cartridges should be stored with the post extended. I can't really understand why as the cartridges are much like the gas struts that hold your boot or bonnet up and spend almost 100% of their lives compressed.

 

2 hours ago, droo said:

Revive is also hydraulic, it's just easier to get squish out. Both Reverb and Bikeyoke are easy enough to reinflate if they lose pressure. The ones you want to avoid storing compressed (if any) are the cartridge ones, cos once they go flat you replace the cartridge.

This is the important bit. If you pull a vacuum on the oil in the post it can boil off gas, which makes your dropper seatpost into a suspension seatpost.

exactly as Droo states, its the lifting the bike by the compressed dropper post thats the main problem. Bonnet and canopy lifting struts do fail and they fail when in the down position.Those applications don't use the same cartridge though. MTB application is much lighter, shorter stroke, andonly has to lift the weight of the saddle not a 90Kg bonnet.

With the adjustable air pressure units also watch out for lifting the bike by the saddle if you in an area where the temperature swings are large like JHB in Spring or autmun/early winter and the bike is stored in the garage. The cold temp decreases the pressure in the cartridge so easier to pull a vacuum on it and cause that boiling effect.