Spotlight: OneUp 90 mm dropper seatpost review

Just released, this dropper seatpost is the shortest option on the market. It's perfect for kids, XS bikes, and gravel rigs.

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That’s quite literally what I said out loud to an empty room, unexpectedly, when first unboxing OneUp’s new 90 mm dropper seatpost. 

With just 90 mm of travel (or less), the new seatpost is the shortest travel dropper OneUp has ever produced and according to the Canadian-based company, it’s the most compact dropper on the market yet. It’s intended to be the answer to the relatively common problem of droppers often being too long for kids’ bikes, smaller adult bikes, or really any bike with a minimally exposed seatpost and/or an interrupted (not straight) seat tube.

OneUp’s claim to creating the most compact dropper seems correct to me as a few months back I intensely researched options to fit my partner’s extra-small full suspension mountain bike and settled on a 100 mm travel KS that was literally millimetres on the right side of fitting in the frame. Most others I researched wouldn’t fit due to the length of the remaining post that had to sit inside of the seat tube.

Had this new OneUp 90 mm post existed back then, it would have likely been the one and only post on my shopping list. 

How short is it?

The new 90 mm post sits at just 292 mm short when fully extended. OneUp’s low profile design means that the saddle clamp and main seal section add only approximately 30 mm to the travel measurement. Or put another way, you only need 120 mm of seatpost exposed with this dropper.

And where things get even more impressive is that OneUp’s design allows you to easily add travel-limiting shims in 10 mm increments, meaning you can reduce the travel of this seatpost down to just 70 mm and save a further 20 mm off the above measurements.

By comparison, the KS LEv Si that I bought for my partner sits at 345 mm long for the 100 mm drop version. The total exposed length of seatpost is 144 mm, 24-44 mm more than the OneUp depending on the desired travel. Meanwhile, the KS’s lower section length (that sits in the frame) is 200 mm, while the OneUp’s is just 172 mm.

A proven design

This new stubby seatpost shares all the same running internals and features as OneUp’s well-proven and well-loved droppers. Any review of any dropper seatpost over on our sibling website Pinkbike always spurs countless unsolicited comments offering praise for OneUp’s solid, no-fuss, and fairly priced dropper post range. Needless to say, this seatpost lets you move the saddle and up-down easily and reliably – and that’s really all most of us want from such a seatpost.

The solid build quality and thoughtful design keep wiggle and unwanted movement to a minimum. The return speed is fast and reactive, and there’s a good feel at the lever that you can modulate for where you wish to place the saddle within the height range. It also happens to be one of the easiest seatposts on the market to install and service – also good things.

And then there are the finer elements such as adjustable return speed (based on air pressure, changed with a regular shock pump) and the simply reliable two-bolt seat clamp that works with all common saddle rail types. 

All popular saddles welcome.

Our global tech editor James Huang runs OneUp’s droppers on a number of his bikes and has little bad to say about them. His only criticism is related to the main seal which lets more crud into the seatpost than expected, something that means basic cleaning and re-greasing is required semi-regularly to stop the seatpost from getting sticky in its travel. Thankfully it’s a quick task.

OneUp’s posts feature a user-replaceable air sprung cartridge that requires no specialist tools for replacement or servicing of the post. OneUp backs the seatpost with a two-year warranty. If things go wrong after that time, full replacement internal cartridges are available for just US$60.

Diameter limitation

All that said, there are some important stipulations to be aware of. Firstly, OneUp only offers this new seatpost with internal cable routing (the cable enters the post from the bottom). This rules out many older bikes without provision for internal dropper cable routing.

And then there’s the fact OneUp is currently only producing the post in 30.9 or 31.6 mm diameters. They currently don’t offer it in a 27.2 mm diameter, and so while the 90 mm travel is probably ideal for gravel purposes, it, unfortunately, won’t fit a number of popular gravel bikes. I hope this limitation changes in future.

It’s also worth noting that the respectable US$199.50 price tag is just for the dropper post. OneUp sells its impressively good remote (with included cable kit) separately for US$59.50 (£49.50 / €59.50), or alternatively, many other brands of remotes work well with this post (such as Wolf Tooth or any other remote that can clamp a cable, including drop bar versions). 

OneUp’s remote, which pivots on a sealed cartridge bearing, is extremely good.

OneUp announced the new 90 mm post alongside a new behemoth 240 mm travel version. The new 90 and 240 mm versions join the pre-existing 120, 150, 180, and 210 mm versions. The available travel (and therefore exposed length) of all models can be shimmed down by up to 20 mm. The new 90 mm version is expected to be in stock shortly.

Price: US$199.50 / £179.50 / €199.50 (includes international delivery)
Weight: 377 g, post only. OneUp’s remote is 45 g (inc 22.2 mm bar clamp) and the provided cable and housing is 62 g (uncut lengths). 
More information:

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