After 30 years of making components in the UK, U.S.E. introduced their first dropper seatpost late last season. Manufactured in-house in West Sussex and already updated this spring for improved performance & reliability, the mechanically-actuated, infinite-adjust post was something of a mystery, so we wanted to get a better look inside USE’s latest dropper.
U.S.E. Ultimate Helix mechanical dropper seatpost
Named after the helical internals that guide it up & down and allow it to mechanically lock in place at any height, USE wanted to address the inherent issues that “plague other designs associated with air and oil pressure”. The thinking was that “simplicity results in reliability”, and although the helix itself isn’t the most simple design, it does reduce the number of small internal parts subject to failure.
The Helix post looks like pretty much any other dropper from the outside, but it is obviously what’s inside that counts…
Breaking it down, the Helix is made up of a number of key elements, CNC-machined from 7075 alloy in their workshop, just underneath the office where it was designed. The 7075 head is forged out of their shop, then machined in-house along with the telescoping shafts, collar & the unique helix gear. The rest of the internal components are a few engineered composite gears, springs & such.
The way the post actually works… when the remote cable is pulled, the lower clutch gear (with the stacked spring, above) is pulled away from the teeth on the bottom of the helix, allowing it to spin freely. As the helix spins, the seatpost can freely rise or fall, moving up and down with its fine helical gear threaded into the bottom of the upper slider. Release the cable, and those clutch gears grab each other, preventing helix rotation & seatpost movement. Bushings ensure a good seal & internal guides prevent rotation.
Up top, air pressure inside the slider provides an adjustable return spring. More pressure makes the post return fast with a satisfying top-out clunk, less pressure makes return slower. USE calls it Speed Control, but a narrow range around 50psi seems to be ideal for just about any rider.
Saddle clamping & position is managed by USE’s standard one-bolt head, with 10mm setback. And internal pressure is adjusted through a typical Schrader valve on the back of the head.
The U.S.E. Ultimate Helix mechanical dropper post is available in either 30.9 or 31.6mm mm diameters (which share the same diameter upper & internals) and in 125mm or 165mm travel versions. Claimed weight for the 425mm overall 125mm travel post is 513g, for the 520mm overall 165mm post is 560g (both in 30.9mm diameter.)
The post does have a relatively tall collar, and a pretty long overall length, so it will be important to double check if it will fit your bike before buying.
Pricing & availability
The Helix dropper is available direct from USE for £260 with 125mm of travel or £285 with 165mm of travel. Ultimate offers its Helix Lever thumb remote separately for £50 with either a standard bar mount, Shimano direct mount, or SRAM Matchmaker kits so you get just what you need.
We’re curious to see how it stands up to real trail use & abuse, so we’re going to spend some time riding the Helix this summer, together with the Ultimate 35mm Vyce stem & Boom carbon bar that have already shown themselves to be a great balance between stiff control & reasonable comfort.