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Can you imagine what it was like when the first Apple engineer with the first prototype iPhone typed in their first search on Yahoo or Lycos or whatever the hell we were using before 2007? I bet they felt the ground shake beneath their feet. It wasn’t long before the smartphone became a must-have for anyone with two thumbs and a working set of dopamine receptors.
The mountain bike industry has seen similar innovations that, from the inside, felt just as earth-shattering. SRAM’s single-ring drivetrain hunted the front derailleur to near extinction in less than a decade. And of course, dropper seatposts have literally reshaped the bikes we ride. But for some reason, that particular revolution is taking a bit longer. The Gravity Dropper, the first production telescoping dropper post, actually predates that first iPhone by nearly four years. And still, somehow, it feels like our industry hasn’t quite figured out this whole dropper thing, especially if you ask anyone over 6-feet tall.
There are only a handful of dropper posts available at or above 200 millimeters of travel. The first traditional, infinitely-adjustable option came from 9point8, but not until 2016. Far bigger fish, RockShox and Fox, didn’t join the club until 2019 and 2020, respectively. And don’t get your hopes up for a 200mm Reverb AXS any time this year.
So, what the hell? This isn’t rocket surgery. Just make some longer tubes and stick ‘em together, right? For a while now, frame designers have pursued lower standover and seat tubes that accept longer posts. And dropper designers are smashing down their stack heights like they’re Big Mac patties. The bikes are ready. Shouldn’t this be easy? Well, yes and no.
“The lengthened post had to be verified by structural analysis that it would be suitably strong enough, and then validated through destructive testing,” as 9point8’s co-founder, Jack Pittens nerdily puts it. “The longer lengths also meant that some new manufacturing tooling was required.” Those longer tubes are under significantly more stress. Taller riders will have their posts farther out of their frames and, of course, they tend to weigh more than those running naturally stronger, shorter posts. As dropper posts approach or exceed 200mm, overall length becomes simultaneously more difficult, and more necessary, to keep to a minimum. That’s the approach that OneUp has taken, and it’s why minimizing exposed length and insertion depth is part of their posts’ narrative throughout their size range. And they had to get pretty granular to do it, with innovations in things as seemingly insignificant as the design of the actuation mechanism. Jon Staples, engineer and co-founder at OneUp, opened our conversation with the role overall length played in their design. “By creating a 210mm drop post with only 243mm of collar to rail length we were able to dramatically reduce the peak stress in the upper tube.”
And that’s just the tubes themselves. Longer lengths put significant strain on a dropper post’s bushings, the rings of plastic-like material that allow their internals (or those of forks and shocks) to move freely. These are the points of contact between a dropper’s upper and lower tubes, and they need to be spaced farther apart on longer droppers. Not just to protect the post’s structure, but to protect themselves. Excess stress on bushings can cause premature and uneven wear.
“As that occurs, your radial clearance between the post and the bushing tend to increase and you develop some play in the post. As that happens, you can have your seals disengage,” says Bill Brown, director of engineering for suspension at Fox. And with more than 40 years of suspension design experience, Fox knows a thing or two about how to make a tube slide through another tube. Fox’s first dropper, the D.O.S.S., came out nearly a decade ago. But it still took them until just three months ago to drop a 200mm Transfer, and only managed a 175mm version about a year before that.
As dropper posts approach 200mm, overall length becomes simultaneously more difficult, and more necessary, to keep to a minimum.
That brings us to The Fact of the Show: “The move from 150 to 175 was actually a bigger project than the move from 175 to 200.” I think I heard a record scratch on the Zoom call when the director of engineering at Fox’s Asheville, North Carolina, office, Josh Coaplen told me that. But a couple other brands, including RockShox, had a similar story. Turns out, it can be a lot harder to stretch an existing post than it is to just design a new one. If you remember, that’s exactly what both Fox and Rockshox did soon before they released their 200mm posts.
“The newest Reverb Stealth C1 was planned from the very beginning to be a 200mm post, with travel options from 100-200. That 200mm drop was baked in from the start and drove the majority of the design work,” explains SRAM’s product-manager-turned-marketing-guy Chris Mandell. All of those strength issues can be more easily addressed if you’re not tied to a design that was conceived in an age when 100 millimeters felt like a gift from the gods. And it’s not just the strength. In a few cases, there were internal mechanisms that needed to be retrofitted for longer lengths. PNW got pretty creative when designing the bits that actually control the movement of their 200mm posts, as PNW co-founder and CEO Aaron Kerson explains.
“We had to change our cartridge design to fit both the oil and air chambers into a smaller package. On shorter travel posts, we’re able to split the two chambers so they’re stacked on top of each other, which is more efficient to produce and less complicated to engineer. For the longer-travel posts, we use a side-by-side dual chamber design, which squeezes more into a smaller size cartridge.” For Fox, the extra motion caused issues with the original design’s internal floating piston (IFP), which accommodates for oil displacement as the post compresses. The pressure increased enough that it was difficult to get the post to the ground floor.
Alongside all this is the creeping introduction of the 34.9 seatpost diameter, long adopted by Specialized, and now by Trek, whose Bontrager Line Elite dropper now comes in a 200mm length, but only in the 34.9 diameter.
“The larger diameter helps us to get to that length while keeping things smooth and durable—less flex means less binding and friction.” Alex Applegate, marketing manager at Bontrager, is more bullish on 34.9 than the rest of the manufacturers I talked to. Most of them offer posts with a 34.9 lower diameter, but few besides Bontrager have sized-up the upper stanchion and internals to take advantage of the extra room. They could, though. And they acknowledge it would make it possible to design equally strong posts with slightly shorter overall length. A couple designers even said they’ve got plans that could be ready to go if the industry ever widely adopts 34.9. But that hasn’t happened. In fact, a big reason Bontrager went for 34.9 is related to what may be the main reason the 200mm dropper has been so slow to develop. And it made everyone a little uncomfortable when I asked.
“The move from 150 to 175 was actually a bigger project than the move from 175 to 200.”
“We have to make a business case for what we work on, and it’s an easier business case when there’s a lot of OEM business behind it,” says Bill Brown at Fox. OEM means “original equipment manufacturer.” It’s shorthand for parts that get specced on bikes, not just sold aftermarket. That’s the sweetest plum. Sure, component manufacturers take a bit of a hit on price per unit when selling parts for spec, but OEM sales happen in huge volumes all at once, and usually come at predictable intervals. Plus, they’re far simpler, logistically. They have simpler packaging and don’t get shipped or change hands as often. Fox is quick to point out that wasn’t necessarily the driving factor in the 200mm Transfer’s development, but with so many brands still so hesitant to spec 200mm posts, even on XL bikes, there’s simply less motivation to do the heavy lift of developing longer droppers. Even aftermarket, they barely pull their weight.
“It’s funny when you compare sales data versus the attention longer travel posts get in forums, comments on our ads and customer service emails,” says Aaron Kerson of PNW, “You would think 200mm-plus was 90 percent of the market. Our sales data show that 15 percent of our dropper sales are 200-plus posts, with relatively equal splits between 125, 150 and 170,” Five years ago, there may have been more motivation from a sales perspective. When 9point8 first released their 200mm post, it was 30 percent of their sales. They were the only game in town. Now, it’s closer to 10 percent. This is less of a risk for Bontrager, as the overwhelming majority of 34.9 Line Elite posts will end up scoring OEM spec on bikes. Trek bikes.
But nobody I talked to in any of these brands was that cynical about their 200mm dropper posts. If they had been, they wouldn’t have developed them in the first place. Longer droppers don’t have the same broad audience as 150mm droppers or 1x drivetrains or iPhones. But to me, someone measuring 6-foot-2 who now cannot ride anything shorter, they are worth the hassle. Bill Brown at Fox puts it simply: “Any time we’ve offered anything with travel, people have always wanted more.”
Photos: Anthony Smith