I recently installed the new Fox D.O.S.S. adjustable height seat post on my trail bike and have to admit; I wasn’t sure what I thought of it from the initial reports online. While the post itself looked clean in its design, the dual thumb levers looked a bit much. However, now I’ve installed the unit on my ride I have to say; having a matching Fox fork, rear shock and seatpost on the bike looks pretty damn snazzy. In comparison to the dated and clunky-looking Gravity Dropper Turbo model it replaces, the clean lines of the post look incredible. The main thing I took away from my first ride with it though was that the post just looks and feels solid.
Confidence in a product goes a long ways. So does ease of use. Opening up the box we found the installation to be very basic, a feat easily accomplished by any reasonably competent home mechanic with a good cable cutter. You start by bolting the post into the frame like any other post. Bolt on the bar mounted thumb lever, (which is hinged, nice) cut the housing to size and route it on the frame. It was about the same difficulty level as installing a cable brake. I didn’t have to bleed the post or monkey around with any weird proprietary allen keys or bleed kits. It was so easy that I thought I was missing something, and started reading through the instruction manual for something I may have missed. Except that is was that easy. Because it’s a standard cable with housing, there is a slight bit of cable stretch during break in, which can be adjusted via the barrel adjuster.
During the first rides with the post I kept waiting for something weird to happen. Every post I’ve owned has been temperamental or had some weird quirk. The Gravity Droppers need a tap of your ass in order to activate. The Crank Brothers post has crazy mad play. The Reverb needed to be bled out of the box, and is prone to breaking if you’re not careful about how you mount it in your repair stand. (and the post lifts up when you grab your bike by the seat— I hate that.) In fact, I was almost happy when I found something that felt off. And there is was.
The one flaw I’ve found to date with the D.O.S.S. (henceforth referred to as the DOSS) post, that isn’t really a flaw. Although when the post generally doesn’t have any play, (the only post I’ve ever run that doesn’t!) when the post is lowered and then raised, there was a slight bit of play before it completely engaged. It totally jiggled for a moment. But then, something clicked, and the play was gone. And that was that. Not even a flaw, just an interested quirk that would never be noticed while riding. A quirk only someone that has spent hours rebuilding numerous adjustable posts would even notice, or by folks admiring your post during the parking lot test.
On the trail, the post works as promised. The inside thumb lever (which is unique in that you can select from several different mounting options, another well thought out feature of the post) releases the post so that you can drop it 40mm to the trail mode, great for times when you want it just a bit lower, but still need some leg extension. I found that I could even lower the post while I had my full body weight on it. It took me a few hours of riding before I grew accustomed to the actual location of the thumb lever, as its a bit different from the previous post I had mounted, but by ride number two it wasn’t an issue. Halfway through my second ride I was able to still get the post lowered on bumpy sections of trail where I had waiting a bit too long before dropping it. The best part of the post to date is that I never once had an issue with the post “popping” back up accidentally. Ok, that and you can actually pick up the bike by the post without it extending. That’s something I didn’t realize I missed. In fact, after dealing with less than reliable adjustable height posts, the reliability of the DOSS has been utterly refreshing. The lever feels solid, and when I got a flat tire on the ride, I flipped the bike upside down to remove my wheel without any concern on damaging the thumb lever. With other posts I’m always concerned about durability of the thumb lever.
Only time will tell how the DOSS holds up over time, but at the moment, although the DOSS is a bit more expensive that the other options, we feel it’s worth the investment. (assuming the post remains as reliable- an issue with almost all adjustable height posts)
There are a number of other articles online about the technical nature of the post, but having torn apart a number of posts personally, I honestly am not concerned about the technical nature of it- I just want it to work. I have no doubt a season from now I’ll be familiar with the inner workings of the post, but until then I just want to ride and not have to think about it. From my initial impressions, the DOSS has the potential to go the distance. Although the post I’m running isn’t exactly the one I would ideally run, (I currently have the 4″ drop model as opposed the 5″ drop, and since I like to dirt jump, I prefer my seat low as it can possibly go) I have to admit this is one fine piece of kit. I’ve wanted a quality adjustable height post since the Height Rite, and while I’ve owned and tried quite a few of the available post options, my first impression of the Fox post is that it lives up to the hype.
SPECS: (via Fox Racing Shox)
Post Diameter Options
Drop Size Options
- 4 in / 100 mm
- 5 in / 125 mm
- Climb (fully extended)
- Trail (middle position — 40mm below Climb mode)
- Descend (lowest position)
- Left or right
- 4 position mounting options (left/right and 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
- Easy travel-setting activation
Adjustable Speed Return
- Air pressure is used to adjust the speed return (10-25 psi)
- No slip, 2-bolt design
- 1.37 lbs / 620 g (30.9mm x 5″)
post, lever, hardware, cable and housing
Check it out: Fox DOSS Adjustable Height Seat Post
disclaimer: I coach mountain biking for Bikeskills.com, and receive Fox product at industry pricing. This in no way shapes my opinion on this product.