# DNM dropper post



## mack_turtle (Jan 6, 2009)

I have never ridden a dropper but I wanted to give it a try. I inherited (as in, free) a 31.6 mm external routed DNM seatpost. It was given to me because it failed on the previous owner and he didn't think it was worth the hassle to send it back to Taiwan for service. I played around with it and immediately hated the thing. it's been gathering dust in my cabinet since.

when you pump up the seatpost per the instructions, it stays up until you put any pressure on it. I can easily compress with my hand, which means it will never hold my body weight while riding. it compresses more easily when the dropper trigger is actuated, which is a good sign. it just doesn't stay up under normal weight at all, regardless of how much air I put in it with my shock pump.

DNM told me to spray WD-40 on the seat post and that should make it work again. no joke, that was their solution. I actually tried this and it predictably did nothing to make it better. they said that I could send it to them for warranty service, but they charge quite a bit more than it would cost to just buy a new one! They also suggested I take it to a bike shop, but they provide no instructions for bike shops or individual users. I worked as a bike shop for several years and I can rebuild my Reba with my eyes closed. if I can't figure it out, I doubt any bike shop can. any shop is just going to get pissed off when DNM tells them to mail it to them and charge me $200.

I want to give servicing this post a try. The manufacturer said that I "can't" take it apart because they have a special jig in the factory. (which is idiotic, because they are making what is effectively a 100% non-serviceable, disposable part.) someone put it together in the first place, so it must be disassemble-able.

The bottom of the seatpost has a threaded plug with a schraeder valve in the middle. the plug has two small holes across the diameter of the plug, presumably to get a pin spanner of some sort in there for assembly. I have tried to loosen the plug with a snapring plier but I can't get enough grip on it to crack it loose. I can put it in a vice and risk scratching the daylights out of it but it feels like my snapring plier is going to break before it breaks the plug free. so the question is: *how do I crack that plug loose?*

I am aware that I probably won't be able to put it back together again. that's fine, I want to at least try. there's probably a powerful spring in there that's going to eject shoot across the room at the certain point, so I'll take precautions.

If nothing else, I want to clean this thing inside and out so I can separate the ferrous and non-ferrous metals before I tossnthe whole thing in the recycle bin. I don't believe in throwing anything away until I have at least attempted to repair it.


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## noapathy (Jun 24, 2008)

I was curious about this post for a while, but it has enough bad reviews on amazon that I stayed away. Seth's Bike Hacks says the schraeder valve "burps" out a lot of air and to overinflate to compensate..."like an extra 100psi". Worth a shot if you're gonna toss it or thrash on it anyway. Also, he says the switch is a POS if that matters.


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## wschruba (Apr 13, 2012)

Some thoughts having never seen that particular model:

-Use plastic prism jaws in your vise (such as these--other brands available)

-Snap ring pliers != a pin spanner. All but the largest sizes are meant for a rather small amount of force, and they typically have the dogs bent in the intended direction of the tool, so the snap rings don't slip off without provocation. You may be able to use a sacrificial pair of cheap snap-ring pliers from the hardware store (a large size) with the dogs ground down just enough to fit the sockets in the post.

-Look carefully for some other retaining method, such as a coil-type snap ring partially obscured by the threading in the post. It would be uncommon, to say the least, to rely entirely on such a low-torque solution for something under high stress.


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## mack_turtle (Jan 6, 2009)

I finally got it apart. I could not get the bottom cap off for a long time, but it just screwed loose today, no problem. I dug deeper and deeper into it and took it completely apart.

since there are no service instructions, i am not 100% certain that I put it back together again the right way. however, it does not work any better now than before I took it part. at least i tried before it went in the trash.









this whole thing turns me off to dropper posts. I can't imagine any bicycle component being worth this much drama.


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## Jaiblan (Jul 16, 2020)

Good afternoon, greetings, I would like to know if you could fix it, I have a HQS model DNM dropper and I stay on top, it does not go down


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## mack_turtle (Jan 6, 2009)

not sure if anyone can help you. I got mine taken apart and that's as far as I got. I was going to throw it away, but instead I put all the parts in a bag and gave it to my local bike co-op. the bag had a note in it that just says "good luck!"


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## milton_junior (Oct 26, 2020)

mack_turtle said:


> not sure if anyone can help you. I got mine taken apart and that's as far as I got. I was going to throw it away, but instead I put all the parts in a bag and gave it to my local bike co-op. the bag had a note in it that just says "good luck!"


Hello, my DMN SQS that was purchased in 2016, only had problems locking up last week.
In these almost 4 years it was necessary to fill into the air only 2 times. I was amazed by the quality and durability, more than 2,000 km of muddy trails have passed.
I solved the problem of mine by playing wd40 through the bottom hole and next to the seatpost.
I emptied it completely, and applied it abundantly.
returned to function perfectly, I almost disassembled, but I saw in the forum the tip of applying wd40, in my case it solved.


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## Skywwork (Mar 18, 2021)

May be years behind this post but maybe it could help someone. I started to tear my apart when I realize let me peel this disclaimer sticker and behold a second hole appeared under the black sticker around the valve. Took my WD40 and to my amaze I could stick the tube about the length of the dropper and let WD40 all inside the dropper. To my surprise after several attempts the dropper was actuating like when I first got it no lie. Before it was very sticky and would not rebound up once you lowered the dropper. As for air, I can’t still get enough air to get the original length but I am happy the dropper is now popping up fast like before. I have a 125mm dropper and probably lost 3” in air but still works for me since I’m short. Happy I tried wd40. If you try peel alway the sticker and spray into the deeper of the two holes around the stainless coupling plate where the valve goes into the dropper at the bottom. Good luck.


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## Bonnie&Clyde (Sep 14, 2020)

My post started sagging and wouldn't stay up when sitting on the saddle. Check the PSI it was 150. unscrewed the collar with seal on top cleaned it put some light oil on it, screwed collar back on. Now the post sometimes is stuck and wont go down. Then inch by inch pushing the lever it drops. I might try and find the holes mentioned above. I assume we talking by the Schrader valve?


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## Skywwork (Mar 18, 2021)

Bonnie&Clyde said:


> My post started sagging and wouldn't stay up when sitting on the saddle. Check the PSI it was 150. unscrewed the collar with seal on top cleaned it put some light oil on it, screwed collar back on. Now the post sometimes is stuck and wont go down. Then inch by inch pushing the lever it drops. I might try and find the holes mentioned above. I assume we talking by the Schrader valve?


Yes, pull the black disclaimer sticker off and you will find another hole. Not sure but my dropper is about 2-3 years old so may not be apples and apples. Still have issue again..it's not bouncing back good..like sticking when down. Good luck.


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