Oneup Dropper Posts

Measuring Up: Diameters, Travel, and Routing

Getting the right OneUp dropper starts with two measurements: your frame's seat tube internal diameter and its maximum insertion depth. OneUp posts come in 30.9mm, 31.6mm, and 34.9mm - covering the vast majority of modern mountain bikes - with travel options running all the way up to 240mm. That upper end puts OneUp among the longest-travel cable-actuated posts available anywhere.

One firm requirement: these are internal cable routing posts only. If your frame runs external cable routing, OneUp won't work without a conversion, so check your frame's port arrangement before you buy. For insertion depth, measure from your seat collar clamp down to the top of your bottom bracket shell - that figure, combined with your preferred saddle ride height, tells you the maximum travel you can actually use. OneUp's own sizing calculator does the arithmetic cleanly; feed in your numbers and it'll tell you which post length to order.

The custom travel adjust shims - brass pins that slot into the guide channels inside the collar - let you reduce travel by 10mm or 20mm without any tools. Unscrew the mid-cap collar by hand, drop the pins in, and reassemble. Useful if your frame sits right on the cusp of a longer post fitting, or if you're running a particularly aggressive saddle setback. It's a considered feature that makes OneUp a genuinely flexible choice for awkward frame geometries.

Actuation is via a cable-pull remote lever, sold separately. Most standard remote levers - including OneUp's own - are cross-compatible, so if you're already running a quality lever from another setup, there's a good chance it'll work straight away.

V2 or V3: Knowing Which One You Actually Need

The OneUp V2 is the post that earned the brand its reputation. It's proven, reliable, and built around a sealed cartridge that can be replaced in the car park with basic tools when it eventually wears out - no sending the whole post away, no long wait. For most riders on a sensible budget, it's still an excellent choice. Slightly heavier than the V3, but not by enough to matter on a typical trail bike.

The OneUp V3 is where the engineering moved on. The headline changes are SKF wiper seals replacing the standard wipers, and IGUS bushings taking over from conventional bearings. In practice, this means noticeably smoother actuation - less of that subtle friction you feel on a post that's seen a few wet rides - and better resistance to the fine grit that works its way into a dropper during a muddy Welsh autumn. The V3 also shaves weight and drops the stack height even further, which matters if you're right on the edge of fitting your preferred travel. The cartridge is fully sealed and recyclable, a genuine improvement over the V2 in terms of both longevity and environmental credentials.

The honest trade-off? The V3 costs more. If you're riding a hardtail on mixed surfaces and your dropper spends most of its life dry, the V2 does the job well. If you're descending Peak District grit roads in October, or your bike lives in a muddy van from November through February, the V3's sealing pays for itself in reduced maintenance. Compare both against alternatives like RockShox Dropper Posts or Fox Dropper Posts and you'll find OneUp sits at a competitive price point for the level of adjustability and stack height on offer.

If you need replacement cartridges, brass pins, or rebuild kits to keep your post running smoothly, visit our OneUp Seatpost Spares page - we stock the full range of service parts to keep things moving.

Keeping It Running Through a UK Winter

A dropper post in the UK earns its keep the hard way. Liquid mud, fine grit, and persistent damp are the real enemies of a smooth-operating post, and they don't let up from October to April. The V3's SKF wiper seals do a solid job of keeping the worst of it out, but no wiper seal is completely immune to the kind of clay-heavy slop you get on a Surrey Hills ride after a week of rain.

The practical fix is simple: every few rides in proper winter conditions, unscrew the collar, wipe out any accumulated grit from around the stanchion and seal, and apply a thin coat of suspension grease - something like Slick Honey works well - before reassembly. It takes two minutes and makes a meaningful difference to how the post feels. Ignore it for a full season and you'll be chasing a scratchy, sticky action that no amount of cable tension adjustment will fix.

The other thing worth attending to is your cable. UK wet conditions corrode standard steel inner cables faster than most riders expect, and a corroded inner cable dragging through its outer housing is one of the most common reasons a dropper feels sluggish or won't fully extend. Use sealed outer cable housing and consider a stainless or coated inner cable - the upfront cost is minor compared to diagnosing a sticky post mid-ride on the North York Moors. Pair this with OneUp's own tools for installation and you've got a clean, reliable setup from the start.

For riders also looking at budget-friendly dropper options, Brand X Dropper Posts and PNW Components Dropper Posts are worth a look as alternatives, though neither matches OneUp's combination of stack height and travel range. And if you're refreshing your cockpit while you're at it, OneUp Handlebars are engineered to the same practical-first standard as the dropper range.