Fox DOSS Dropper Seatpost

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Fox DOSS Dropper Seatpost

Perfectly Positioned to Ride Any Trail

The all-new D.O.S.S. seatpost complements Fox's CTD ride dynamics system with on-the-fly seat-height adjustability, so you're perfectly positioned to tackle any type of terrain.

CTD 3-Position Integration

Gain complete ride control at your fingertips with the lever-actuated, three-position D.O.S.S. seatpost. It syncs with front and rear suspension settings Climb, Trail, and Descend - for instant performance optimization based on the terrain.

The easy-to-find middle position dual levers and the internal positioning system make it easy and automatic to find middle Trail position every time.

  • Provides 4-position mounting options: left/right, above/below, handle bar
  • Fast and easy reach accessibility
  • Dual levers make it easy to find middle trail position every time
  • Adjustable reach
  • Dual internal cam system for easy travel-setting activation
  • Air pressure is used to adjust the speed return (10-25 psi)
  • Saddle clamp has a no slip, 2-bolt design

If you're replacing your seatpost you may want to get a new saddle too. Take a look at our entire selection of saddles here.

Due to manufacturer restrictions we can only ship this item within the U.S.


Model D.O.S.S.
Material Alloy
Sizes 30.9mm / 31.6mm
Type/Application XC/trail/AM
Length Options 4", 5"
Cable Routing Left or Right
Travel Modes Climb, Trail, Descend
Weight 1.37 lbs / 620g (30.9mm x 5")

Showing Questions 1 of 1

Q: What is the length of the tube that inserts into the frame? I have a lrg trek 9.9 ssl (FS) from 2012. I need to know if it will fit in length wise . (4 inch post )

A: Overall length is 335mm, the minimum insert is 95mm.

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A must buy! - Apr 27, 2014

1 2 3 4 5
5 out of 5 stars

This make a good mtb great! i had everything else on the bike, but finally had to get the dropper post. it works good takes time to set it up properly and i have to run like 45lbs pressure to get the post to come all the way back up, but ill never ride without one now :)

0 out of 0 people found this review helpful
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Love riding with the DOSS dropper - Sep 10, 2013

1 2 3 4
4 out of 5 stars
Denver, CO

I've been riding this dropper post for six months and I love it. The one-inch drop position is great for mild downhill sections and mostly downhill rolling trails. The four-inch (all the way down) position works great for steep drops and fast cornering. I put 12 PSI in it and it works great. I've demo'ed bikes with other droppers and this one is smoother and easier to move down. It's very solid. I really like the two-bolt seat attachment, totally rigid. The only thing keeping me from giving it 5-stars is the clunky remote lever. I made my own mounting bracket from an old brake mount and it works so much better. I don't even use the black lever. After a few rides, I got the hang of just using the silver lever to move it into either position and it works great.

3 out of 3 people found this review helpful
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