Help needed to pick dropper seatpost


Active Member
I would like to use a dropper seatpost on my Haibike Sduro Trekking. Diameter is 31.6 mm.
My need is a bit different from why most people want them. I need the lower saddle height to help me get on and off the bike as I have an ankle problem, not to indulge in brave descents LOL
I have a 52cm frame and I'm 6ft and I usually have my seatpost extended about 4" or 100 mm up for good pedalling action and I should probably have it raised a little more.
Residual from an accident I have limited ankle use on one leg, (brain damage not physical) and my purpose for riding the bike is to improve my fitness and strength as well as agility.
Essentially I would like to ride with the seatpost in an upper position and just drop it quickly when stopping to help me get my feet down on the ground predictably. I would also probably use it when starting off and then very soon after, allow it to come up for better pedalling action. Once i'm going, I have no problems.
Not a youngster LOL.
I don't have a local bike shop with inventory anywhere near me (100 miles) so I want to pick one from mail or online order.
Most of what I have seen online has a length of 450mm or close and because of the Haibike seat tube design with a curve, I think that would be too long. I had to cut 3 or 4 inches off my stock seatpost.
I think I need something with a length of 350 mm and a collar that would allow the saddle to go down to just a short distance from the top of the seat tube. I think I might need to have a "repeatable" upper height position too and i don't know if these posts can do that.
Any help ? Any suggestions? Thanks :)
I put a Giant Contact dropper (there are 2 versions, have to make sure you're getting the second version) on my bulls ebike and love it. Need it mainly for the same reason you do so don't feel silly about it...It is absolutely worth the cost! You're right about needing a shorter length as well. I actually can't use the full 150mm length of the one I got. Probably only using 100mm and it is still very noticeable.

I found mine reading reviews and comparisons and then searching on eBay. You can search the measurements and get good results on there, and most of the big online bike shops also sell on eBay anyway. Sounds like you'd just want to search for 350mm 31.6 dropper and either 100mm or 125mm depending on how much you think you'll want...150mm ones get a little more expensive as well...although mine was about $150 very lightly used and from a shop (I couldn't see any sign of use myself).
There was one or sale in for sale forum here at erb.
First, those downhillers aren't that brave. Lowering the seat to drag their feet when their balance leaves them. Lol
I recently bought a new bulls 45 large frame. I ordered a magura wireless dropper that showed up same day as bike, and fortunately sits all the way down and when fully extended is just right. Blind luck is responsible. Online reviews complain of lag between pushing button and thing moving and button was hard to find without glancing down. I instantly got used to lag time and glued a little bump on top of button so it's easy to feel. I think it works great and recommend it. I'm 6'o, old and stiff also and use it to mount, dis mount, stop and go etc......
Thanks for the very helpful comments guys. Interesting that others need a dropper for similar reasons as me.
I have been studying some as suggested and am pretty sure I have found one that should work for me.
It is a KS Lev DX which has a diameter of 31.6 mm and an extension of 100 mm. When collapsed down it should have a height of just about 2 inches plus saddle thickness above the locking collar of the seat tube which I think was my biggest worry. When extended the 100 mm it should be just about right for good ergonomic pedalling, putting me at about 6" above the top of the seat tube, maxing out at perhaps one inch higher than I have dared to ride so far.
I believe I can run the cable to the mechanism ok and adjustments are not out of the question. Some of the others require running a hydraulic line or cable through inside the seat tube and I think I want to shy away from that because of the mid motor of the Haibike.
After chatting to a mechanic where I bought my Haibikes bikes (online) he confirmed to me that I can run the dropper seatpost cable down inside the down tube, under the motor and then up into the seat tube to the bottom of the dropper post and I think that is what I will do. This changes the model to KS Lev Integra and it will probably be a neater cleaner installation :)
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Not trying to be a magura "shill"(as one guy accused me of because I said Shimano made top quality stuff). But their dropper is wireless, Bluetooth, whatever's. drop seat n hole, attach control button to bars- yahtzee!
Plus, for me, when I put my bikes on work stand- I change seat posts- so I don't screw up my good ones(body float, thudbuster, and now dropper post). Seems if wiring is internal- could be a hassle?
To be fair to you guys and to thank you for your helpfulness, I will explain that I have not bought a Giant Contact Dropper seat post as it seems its not available for 31.6 mm. I feel sure it is a good model otherwise. I have not bought a Magura wireless dropper either as I found it pricey and I don't think I need the wireless feature plus the batteries that need to be maintained. Once again I feel sure its a really good unit !!

I have ordered a KS Lev with interior routed cable, mainly because the collar length out of the seat tube is the shortest I could find. I will comment on it after having installed it. I have been disappointed to see Youtube articles which entirely leave out the job of getting the cable past the bottom bracket however, which depending on the bike frame can no doubt be tricky. On Haibikes however, it seems that its simply done by routing the cable outer underneath the motor. The motor needs to be unbolted and allowed to hang down on one bolt to poke the cable outer up into the seat tube. This means that the cable does not need to be forced through a tight angle. Fortunately I am not challenged by things like that and if I run into problems I will note them :)
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You did the right thing. Dropping as low as possible and still raising enough to accommodate correct seat height trumps out all other actuating methods or installation considerations.
I have now installed my Dropper post. Installation was not really difficult. I plan to post pictures on the Haibike section and I hope to ride the bike very soon too, weather permitting.