giskard

I've already posted this in the Commuting thread (dunno why but there ya go) but didn't get any replies so I've re-posted here where it's probably more appropriate.

Anyway....

The 2007 range of higher-end Dahon folders include a BioLogic Zorin PostPump as standard, which seems like a great idea. I'm sure I've read somewhere that post pumps are not a good thing as the seat post is weakened. Is that the case?
I'm possibly going to buy a Dahon Mu P8 which (I think) has a BioLogic Zorin PostPump as standard so I'd like to know if here are any issues with this particular post pump and with post-pumps in general. Are there a number of manufacturers of post-pumps out there? A quick Google search seems to indicate just the one.

Cheers

Johno

tellyho

I don't even know what a post pump is.

waterrockets 

He's talking about these:
https://www.dahon.com/technology/component/zorin.htm


I don't see why it would be any weaker than a normal seat post, but I have no experience with them.

giskard

No wonder I didn't get any feedback when I posted the same qustion in the Commuting forum!

Moose

That looks pretty darn cool. Falls under the category of "Why didn't I think of that"

Most folders use long seatposts, these things may be too long for a regular bike, but I doubt they are weak.

tellyho

That's wild! Can't imagine it would be detrimental to the structure of the seatpost. Get one so we all know how it goes!

giskard

If I do go for the Dahon Mu P8 or any other bike that includes a Zorin Postpump as standard, I'll let you know how I get I get on with it and if it's any good.

Johno

froze

Why would you want a pump that you have to remove the seat post first to access it? Then have to make sure the seat is properly adjusted everytime you replace it. YUK! That's additional time, plus could eventually weaken and or strip the bolt if you accidently cross thread it while attempting to replace it then you will have to ride the bike while standing; plus the diameter of the pump to get it to fit inside the post has to be very small thus strength of the pump may not be very good. Personally I would hate that pump due to just the hassle of removing the seat post all the time just to fix a flat just for that problem alone.

Don't forget a lot of manufactures claim their pumps can reach X psi but in real life they all seem to be about 10 psi less then their claims.

If you want a small out of the way pump why not just a get a mini like the Torelli Aria which is the smallest and lightest pump on the market and still reach 90 to 100psi that attaches to the side of your water bottle cage with included brackets? These pumps use to come in different end caps colors, the one shown is black mine is yellow, not sure if other web or LBS bike stores have the other colors available, you would have to do a check. https://www.torelli.com/product_info....products_id=59

ollo_ollo

I would imagine any bike using this pump would have a quick release type seat clamp, but the criticism of the pump's efficiency due to a small diameter may be true.

mtnbiker4791

Seatpost pumps have been around for along time 20 + years. Had one about 20 years ago for my mtn bike it worked well. Cant remember the brand off hand right now.

froze

That's strange...I'm not saying that to say your wrong; I mean that after 30 years of riding and 10 of those racing, I have never seen a seat post pump either on a bike or at an LBS, nor ever heard anyone mention it!!! I must be living in the Twilight Zone.

Quijibo187

not that strange, you've probably never seen or heard of them because they often don't work well, so nobody wants/uses them. we have one in the basement of our shop, so I tested it out, it was very awkward to use and not as efficient as a dedicated pump.

masiman

There were always gadgety. Because they never performed well they never made it to wide distribution. I never saw one, but I remember a write up or ad for them some years ago.