See Our Selection of Race-Ready Disc Road Bikes »

FOX Racing Shox Doss Dropper Seatpost with Remote Lever


Item # FRS0138

Select options
  • Select options
  • 4in Drop, 30.9mm ($299.00)
  • 100% Guaranteed Returns
  • Free Shipping on orders over $50

Item # FRS0138

Drop in.

Fox wasn't quick to jump into the mountain bike suspension market. But, because of its motor-sport suspension knowhow, when they did it made a huge impact to the market -- for the better. The same holds true for its introduction of the Doss Dropper Seatpost with Remote Lever.

One aspect that's detracted from the utility dropper posts is lateral and rotational slop. When riding aggressively, you need to know what the bike is doing, and one way the bike communicates to the ride is through the saddle. To ensure nothing's lost to poor tolerances, Fox uses a dual internal cam mechanism to solidly lock the post into position.

One cam controls the anti-rotation apparatus, and the other controls post height. One nice feature to this system is that it's self-adjusting. As you use any post, wear is inevitable -- and, tolerances will be compromised. The Doss, however, will remain as solid as it was the day you installed it.

The cams are actuated via a handlebar remote with three distinct settings, which coincide with Fox's new Climb, Trail, Descend (CTD) approach to suspension settings. The ergonomic, all alloy remote can be mounted left or right, and above or below the bar to suit compatibility with any cockpit setup. The lever's reach is also adjustable to fit different preferences and hand sizes.

Another unique, adjustable feature is tune-able speed return. By adjusting pressure in the Schrader valve located below the post, you can speed up or decrease the rate which the post returns to its full height. And, the system is failsafe -- the post will always operate if pressure is lost.

The post uses a traditional two-bolt clamp that's simple to dial in the correct saddle level and fore/aft position. The Fox Shox Doss Dropper Seatpost with Remote Lever has zero offset and comes in either 31.6 or 30.9mm diameters, and has a 4in or 5in drop option.

  • Aluminum post with 2-bolt seat clamp
  • Remote handlebar mount lever
  • Zero offset

Tech Specs

30.9 mm 31.6 mm
Actual Weight:
4in Drop, 30.9mm: 620g

Reviews & Community


Write a review

    Add a:
  • Photos
  • Videos

No file chosen

Rather attach a photo from your computer?


Only jpg, jpeg, png, gif or bmp files please.

Submit ReviewCancel

One of the Best

  • Familiarity: I gave it as a gift but have feedback to share

These days there are a ton of options for droppers. Chose this one for a few reasons...
* Air/mechanical construction has been more reliable than hydraulic designs in my experience
* Fast, smooth operation
* Easy to maintain
* One downside is that the post lever is super unwieldy and crowds the bar, but that seems to be typical feedback at this point

Overall, love this dropper!

Droppin bombs

    So I added a few upgrades to my Scott bike while deployed and I noticed a buddy of mine had a seat dropper. Well I wanted one. So I did some research and I found the fox doss dropper. Well it was easy to install. My bike had to have an external rout for my set up and it worked perfectly. The dropper I purchased has a 5in drop due to me be 6'1" ft tall. I didn't have to adjust the pressure at all. Straight out of the box the speed of return was excellent. Now, if your not careful it will sack tap you. So once I got it on the trail I was feeling like testing my luck so I went to descend mode and really kicked the trails ass. I've had no issues with play in the dropper and I'm glad to say it has allowed me to challenge myself with speed on approach and better my technique with my seat being out of the way. I recommend fox to anyone.

    Droppin bombs

    What is the total seat post length of the 5 inch drop option?

    I could not find the exact measurements, but the packaging length is 19" for the 30.9 and 18" for the 31.6.

    does anyone have a picture of the lever set up? I'm trying to see how much clutter it really brings to the handle bars.

    Best Answer

    Hey Josh,

    I have this post on my bike. I'll take a photo and e-mail it to you tonight!


    The freaky lever ruins it

    • Familiarity: I've used it several times

    The post works fine and I like the set stops so it's the same levels of drop each time. BUT the lever is a monstrosity! It's difficult to get it positioned correctly and it clutters the handle bar. I really wish they has a small activation trigger, like all the competitors. Then it would be a great post.

    How do you decide between the 4" & 5"? I'm 6'2", would be going on an Intense Tracer. Riding mostly All Mountain, 160mm travel bike if that helps? Thanks:-)

    Best Answer


    Typically the longer version is for taller riders. I'd go 5" unless you prefer one with a little less drop.

    . If you have any questions feel free to reach out to me direct. My number here is 801-736-6396 x 5630 or email


    • Familiarity: I've put it through the wringer

    Solid dropper post with some quirks:

    1. The lever is massive, which makes it hard to position next to other business on your bars

    2. Stiff lever action--it isn't long before you get a mondo thumb

    3. Middle position isn't quite right

    4. Slight play in *my* post after about two months of riding

    5. Seat-level cable connection means that (like many posts) you're faced with cable drag and housing management issues that can become a PITA

    Otherwise, I love this thing. Really, it does the trick. I'll keep it until I can find the pennies (or justification) to upgrade to a KS Lev.

    Paired the DOSS with the Superlight 29

    • Familiarity: I've used it several times

    I agree wholeheartedly with the positive reviews here. I paired the 4" drop DOSS with a Santa Cruz Superlight XT 29'er and am very pleased. Some comments to offer here:

    1. Excellent quality of materials and workmanship. Entire unit is solid and very precise feeling.

    2. Fox falls short on the instructions for set up. They should have provided a guide for seat post psi versus rider weight to spare the new user having to experiment, and repeated mounting and unmounting the DOSS to access the relief valve. I weigh 160 pounds and finally dialed in the right pressure after a few tries to just under 5 psi. If your a heavier rider than 160 I'd say 10 psi would work for 185 lbs, and the max of 25 psi might only be practical only for someone weighing over 220.

    3. The slight free play noted by others happens only for the moment the seat post is transitioning to a different height. Once you release the lever the locking mechanism clamps up the post very well.

    4. There is no dampening mechanism for the return to Climb height from either Trail or Descent. So the seat comes up FAST. Even with 5 psi.

    4. Raising the seat just takes a little common sense given the lack of return dampening. Depress the lever to release the seat lock as you lift your butt. DO NOT raise your butt before pressing the release lever or the seat will cover that gap in about a tenth of a second and slap your junk up into your skull and out you nostrils.

    Anyway, an excellent product and added equipment feature that presents noticeable benefits to riding terrain variations.

    LOLOL @ "DO NOT raise your butt before pressing the release lever or the seat will cover that gap in about a tenth of a second and slap your junk up into your skull and out you nostrils"...Seems like Rockshox mite be the better bet since you can adjust the rate at which the height compresses and depresses...

    Best I've used!

    • Familiarity: I've used it several times

    Working like a champ. I've used several droppers and this one edges them all. The lever is kind of huge but I appreciate it now because I don't have to look down to find it and it's easy to push to engage. Dual button is not necessary for me but some may like the dual lever. The seat drops down into both heights real easy and pops up at the perfect rate with the recommended psi. I set the post at xc riding heights find the first drop height to be really good in mixed terrain and usually sufficient for everything but super steep or really gnarly terrain. I don't feel any play in the seat at all when riding.

    Mostly Good

    • Familiarity: I've put it through the wringer

    Nice mate to Fox fork and frame shocks. Small amount of up/down play (2-3mm) when all the way up. Cable guide will rotate around to back of post which helps when locking in a bike stand. Recoil/return is powerful with the advised 25 psi. - make sure you're in the right spot or it will spank your junk. Seems un effected by cold in contrast to what I've seen from friends with other models.

    I put the 4" unit on a 5" travel bike.

    Your bike stand clamps around which part of the seat post? The brass-colored extension or the black base part? Is it OK to clamp around the former and not worry about damaging the internal mechanism?

    is this the newest one that comes with 3...

    is this the newest one that comes with 3 settings up down and lowered but not all the way down

    Best Answer

    Yep, 3 position like the Fox Shocks basically. CTD

    1. Fully Extended - Climb

    2. Mid Drop - Trail - Depress Both Levers Together

    3. Full Drop - Descend - Big Lever Only

    I posted feedback about a slight amount of play in the post but finding that common in almost all makes after talking with many riders in an Enduro Event. This is a good seat post. Hope that helps.


    Solid and Reliable.

    • Familiarity: I've put it through the wringer

    I bought one for my All Mountain bike and love that it has the 3 settings. An infinite post would be too hard to use for how I use the dropper. I set it in the middle position for all my "normal" riding which includes climbs up to 15% grade give or take, then I can extend it the extra 40mm for the Really steep stuff, 20% grade and up. Then I drop it all the way down for the descent. You always have it right where you need it in an instant without having to reset it somewhere in between. It just is a much simpler design, and there is a certain genius to that simplicity. I would imagine it would be a big plus for a racing application. I liked mine so much I bought a second one for my Downhill bike. now I can pedal the flat with a lot more ease and still drop it completely out of the way for the gnarly stuff. The two stage lever makes finding the position you are looking for so easy you can do it at full speed and concentrate on the trail instead of the lever/seat height adjustments.

    Reliable Dropper Post

    • Familiarity: I've used it several times

    Great dropper post. Install is very easy. This post operates in 3 positions only: Climb - full extension, Trail - 40mm drop, Descend - 100 or 125mm drop. It is not infinitely adjustable like a full hydraulic. The cable lever actuation is smooth and the post drops with minimal effort and has a adjustable pressure setting for the air chamber for return speed. You can mount the lever under or over the bar on either side. If you're running a single front ring the lever works nicely under the bar on the left. Stout two bolt saddle clamp is nice.

    Buy it!!

    • Familiarity: I've put it through the wringer

    This has totally changed the way that I ride. It allows for so much more control on the steep downhills. I would definitely recommend this product.