Defective suspension seat post on a Fold XS bike

wings02

Active Member
The suspension seat post on my Fold XS bike seems to be binding up. When I took off the seat post and compressed the suspension post, it seemed to be binding when released, meaning it was traveling smoothly. I have a seat suspension on my Cannondale and when doing the same procedure, it operated smoothly. Has anyone experienced this same problem? I'm not really sure how to address this on the Facebook page so I'm reaching out to forum members before I ask Sondors directly.
 

Tone Rob

Member
Hey wings02,I didn't have that problem with my seat post,but after a few rides I didn't find it comfortable so I brought a new post
 

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wings02

Active Member
Hi Tone Rob, Did it do the trick? I just ordered a Cloud 9 seat for my wife's Lectric Bike. Have you considered a different seat?
 

Tone Rob

Member
Yes much better I love it and I did change the seat as well to a giddy-up seat on Amazon ,there's a button under the seat that you can make the red light flash,blink,etc
 

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SondorsMXS

Member
Wings02-I have a MXS and have the same issue. I took apart the seat as far as I could, but couldn't take it down farther. Seems you's have to pur it in a vise with protected jaws to hold it well enough to put a wrench on it. Inside, the spring is inside a plastic bag (assumingely for lubricity), even with that removed, the metal post to seat shaft are just cheap and bind. If I had access to my vise and protected jaws, I'd try and take it down further. Some sandpaper and file work would probably fix it.
 

wings02

Active Member
I did get to the spring and removed the plastic also. I have an old Cannondale with a seat post and it's movement is very free. I'm not sure how much better gliding I can get from the Sondors. Might have to go to plan B with the seat post posted by Tone Rob but I hate to have to spend $120
 

SondorsMXS

Member
I hear you. My vise is mounted on a board BURIED behind my storage garage. I'm partially worried that even if I did go through the getting the vise out, and mounted in the vise with jaw protectors, that it is somehow permanently thread-locked or pressed, and I'll butcher up the otherwise mint looking seat post. I HATE scratches on anything I own. It's a OCD thing, no doubt.

I'd love to take it apart further to fix it. My front door handle at the condo I'm renting was very catchy and gritty when turned. I took it apart and filed down the bad looking parts with a Harbor Freight diamond needle file set I have. That file made the $20 door lock feel like a $200 one now! Hoping to do the same IF I can get the post shaft out.

I forgot to say, I also drifted the roll pin out the top of the shaft holding the seat mount on and tried like heck to remove that to push the seat post shaft out. No luck. Even though the roll pin was out I MUST be pressed on. Couldn't remove it at all.
 
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theemartymac

Active Member
I did get to the spring and removed the plastic also. I have an old Cannondale with a seat post and it's movement is very free. I'm not sure how much better gliding I can get from the Sondors. Might have to go to plan B with the seat post posted by Tone Rob but I hate to have to spend $120
If you don't want to try and disassemble and polish the surfaces, maybe get a tube of dry graphite from the lock and key section of the hardware store and tap a bunch in around the seals. Exercise it a bunch and repeat. The dry graphite will pack into the low spots and smooth out the surface interfaces, and won't dry out or grab dirt so it should last quite a while in a relatively sealed environment.
 

SondorsMXS

Member
Wings02-I finally got my MXS seat post apart (likely the same as yours)! Working on smoothing it out tomorrow. Just couldn't take another day with the "stiction" action on my ride yesterday. It sucks.... So I will be putting a craytex bit on the edges (The bearing surface is 90*, not beveled). I think this will improve the sliding action between the nylon/plastic, and the inside of the seat tube. There was also some chrome plating flaking off in the seat tube, as no doubt Wings02 has seen. This however, isn't the problem. I believe the inexact dimensions between the nylon and the hollow seat tube, coupled by the 90* edge tilting into/away from the seat tube. Thoughts? I'll have more T&E on this tomorrow. I tried to protect the tube with painters tape, but since its at the bottom, I'm not bothered it got boogered up. You NEED a vise (under the jaws of most regular vises contain a "V" shaped pipe holder.

1. Use a set of snap ring pliers to remove snap ring under seat post.
2. Use a 6mm allen wrench to fully remove silver screw under snap ring.
3. Remove the spring (its in a plastic bag, assumingely for lubricity.
You need some sort of pipe holder for a vise if you don't have this feature. Once in a vise, a large adjustable wrench on the flats of the second pic (lefty loosey) and if the seat tube isn't spinning, it will finally break free.
4. Once you get it fully unscrewed, it takes several HARD pops to pull the nylon fitting out that is attached to the seat
Note* the roll pin won't help you if you remove it. The seat base is pressed into that piece. I couldn't get it to budge.
 

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wings02

Active Member
SondorsMXS, Very detailed explanation and photos! Although I did not take my seat post apart to the extent you did, I can see it is the same part. Looking at IMG 1150 photo, it seems that the nylon "piston" is what's coming in contact with the tube. Your idea of beveling the edge of the "bearing" (I am assuming you are referring to the nylon piece as the bearing) is a good idea. I would advise using a good amount of graphite dry lubricant to further improve the gliding motion. That being said, it doesn't look like this design is the most efficient especially since the direction of the force pushing down on the gliding piston is not directly parallel because of the angle of the seat and seat post. My solution to this problem is what Tone Bob did. I purchased the NCX seat post from Sun tour. I should be getting this on Friday so I will post a critique
 

Taylor57

Well-Known Member
The Suntour is on Aliexpress for around 70 total delivered and it will solve most of your issues. I also agree on the Giddy Up seat. Comfort and a nice flashing light. An ambulance has nothing on me when it comes to flashing lights...
 

wings02

Active Member
Received the Suntour NCX suspension seat post. Assembly was straightforward. I was only able to test it out for about a minute due to bad weather. Seems to work well. Big difference from the Sondors original seat post suspension which in my opinion doesn't even work.
The minimum seat height is 33 inches from floor to top of seat.
 

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SondorsMXS

Member
Wow, that looks great Wings02! I thought you were getting that rubber bushing seat post for some reason. This thing looks nice!