Fox DOSS Dropper Seat Post
For general trail riding, dropper seatposts are probably the biggest game-changer of the last five years; after you use one it’s very hard to go back to a traditional seatpost—more and more riders are putting one on top of their upgrade list. Despite being one of the leading suspension makers, Fox have been a little slow in joining the uppy-downy party, having only just released their interpretation of the perfect dropper post—the DOSS.
Many early dropper posts were plagued with excessive free play and reliability issues (some of them should have been renamed ‘drooper’ posts), so Fox wanted to make sure they had all the bugs sorted out before hitting the market. The result is a post with some unique features, and a build quality that’s likely to uphold Fox’s reputation for reliability and performance. The DOSS (Drop On Steep ‘Stuff’) retails for $399 and is available in 30.9mm and 31.6mm diameters with either 100mm or 125mm of total drop; our 30.9/125mm post weighed in at 640g including remote, hardware and cables. This makes it 80-90g heavier than the lightest adjustable posts on the market, but comparable to others.
The DOSS uses an excellent two-bolt seat clamp, and the upper post is forged as one piece for extra strength. Rather than attaching down on the fixed part of the seatpost like the latest offering from some manufacturers, the remote cable is fixed up near the seat rails, although somewhat unusually it attaches from the side, not the front or rear. This seems to make cable routing a little easier, with the cable less likely to rub on the rear tyre or your leg when fully dropped. Fox claim it also makes it less susceptible to contamination from spray off the rear tyre. We’re a little sceptical as our cable still got gunked up after a month and stopped the post going into the Descend mode. A quick clean and lube fixed it but the cable is hardly impervious to mud.
Solid not Fluid
Rather than hydraulic internals, the DOSS uses a fully mechanical system to control the height adjustment. It’s a very sophisticated setup that uses a series of ball bearings and cams to lock, and another set of cams to secure the four anti-rotation keys. Cleverly, the anti-rotation keys retract when you adjust the post to minimise wear and friction, and they’re also self-adjusting so should theoretically keep the post rotation free throughout its life. The DOSS locks into position with a reassuringly mechanical ‘thunk’ so you’re left in absolutely no doubt when you change settings; we liked this feedback a lot.
The DOSS does not have infinite travel adjustment, but rather has three set positions; Climb (fully extended), Trail (40mm below Climb), and Descend (fully compressed). Whilst some riders will prefer being able to position the saddle at any height they desire, we found the three positions worked very well. In particular the middle Trail position was extremely quick and easy to find, with no need to partially weight the saddle and then finesse it to the desired height. This setting works great for flowing and twisty trails where you want to be able to move the bike around underneath you, but still need to throw in a few pedal strokes between turns. Return speed to full extension is adjustable via a schrader valve, and the maximum pressure of only 25psi means that the seals should last a long time.
The remote has two levers; a shorter black one which only drops the post to the Trail position, and a longer silver one which allows the post to drop all the way, as well as returning the post to the Climb setting. The remote can be setup on either side of the handlebar and either above or below the bar, so in theory you’ve got plenty of placement options; you can also adjust the reach through three different positions. If you’re not running a front derailleur the ideal location for the remote is under the left side of the bar, where it’s out of harm’s way. This is also the most ergonomic position; your thumb is already under the bar when riding and the remote’s action is similar to operating a shifter, so it’s quite intuitive.
Anyone with more than one chainring will be running the remote above the bar, where its size and shape make it prone to crash damage (we bent ours twice). That being said it is pretty solid, so whilst the handlebar bracket may bend, it’d take a massive impact to stop it working altogether. With the remote above the bar you need to move your thumb up and over the grip to operate the levers, which is not ideal and it requires more time and hand effort than some other remotes on the market.
In terms of the old bugbear of reliability, we’ve got nothing but good things to say about the DOSS. Like all dropper posts there’s a little play at the saddle but it’s certainly not something you notice whilst riding, and over the three months we’ve been using the post, it hasn’t changed one bit. It’s operated smoothly and reliably every time (cable maintenance notwithstanding) and although it’s too early to say for sure, our gut feeling is that it’ll keep going for a long, long time.
It isn’t the lightest adjustable seatpost out there, nor does it have the best cable management or the most ergonomic remote, but there’s still a lot to like about the Fox DOSS. It changes quickly and decisively between settings, is very solidly built, and may well prove to be the most reliable dropper post currently available. If you’re considering getting a dropper post, and particularly if you run a ‘one-by’ drivetrain, make sure the DOSS is on your shortlist.
Sola Sports (02) 9550 1655 / www.foxracingshox.com
