BEHIND THE PRODUCT: G SERIES DROPPER POST

June 24th, 2022

Those of us who mountain bike understand how effective and important a dropper post is to our riding. A product that hasn’t been around for very long now seems absolutely necessary on any modern mountain bike and trail. The ability to lower your center of gravity and engage different body positions for maximum traction is the key to increased handling ability and, ultimately, more fun.

As gravel bikes progress and become more and more capable, many are noticing the lines becoming blurred between a cross-country hardtail mountain bike and a progressive gravel bike. Simply put, the shape of the handlebar is the only perceivable difference in some instances as tire clearance, and in some cases, suspension have now bled over to gravel bike designs. As we continue to push the capabilities of our gravel bikes and venture onto singletrack that might have been previously traveled only on our mountain bikes, we’ve realized the benefit of tucking our saddle out of the way and achieving a lower body position when descending.

Creating a dropper post that’s gravel bike-specific presented more than a few design challenges. However, as with any project, our product and engineering team took a truly purpose-built approach to the G Series Dropper and aimed to accomplish the following design goals:  

  1. Maximum frame compatibility
  • Featuring a 27.2mm post diameter and including shims for 30.9mm and 31.6mm posts ensures a wide variety of bicycle compatibility.

  1. Sub- 400 grams
  • For a gravel dropper, we wanted the post to be as light as possible without compromising reliability and durability. We achieved this objective with a final full-length weight of 395g that can be reduced to 345g for riders who can cut length off the post and still achieve their proper saddle height and meet the post’s insertion requirements.

  1. Find the “Sweet Spot” of drop.
  • The “sweet spot” for gravel is different for each discipline of off-road riding. The right amount of drop for gravel applications is the amount of drop that allows the rider to lower their center of gravity but still maintain pedal efficiency for short distances and compatibility with bikes that don’t provide as much exposed seatpost for adjustability with a dropper. 

  1. Serviceability and Reliability
  • Dropper posts are often a pain point for mountain bikers and aren’t particularly known for their reliability. So providing both serviceability and reliability was critical in its design. 

  1. Saddle Bag Friendly
  • Gravel riders are often going on long, all-day adventures, and carrying extra supplies isn’t an option – it’s a necessity. 

FINDING THE “SWEET SPOT”

With the steep and rocky Wasatch Mountains in our backyard and a long history of mountain bike innovation, we wanted dropper posts on our gravel bikes almost as soon as we started riding them. Initial prototypes proved to be just as useful out on the flint rock roads of Kansas when pedaling efficiency was demanded, but shorter descents warranted the improved handling a dropper provided. In line with the ethos of our gravel products to provide more confidence, the 40mm of drop puts a rider in a more comfortable and manageable position to descend faster. Similarly, by limiting the amount of drop travel to 40mm, we maintained a saddle position that still pedals efficiently in a dropped position for short periods of time. More travel meant restrictions for which bikes the post would be compatible with, but 40mm proved to be the sweet spot by keeping the entire package lightweight, serviceable, and saddle bag friendly. 

THE INVERTED DESIGN

All ENVE products are born from our ride experience and that of our athletes. Truth be told, we had been working on a short travel dropper post for a very long time. In 2011, our friend Burke Swindlehurst debuted his inaugural mixed surface event, The Crusher in the Tushar, an event that required riders to make a decision between essentially an XC hardtail or a drop bar CX rig to efficiently traverse the Crusher’s challenging miles. While not the first event of its kind in the world, it was unique in our orbit and forced riders to choose, ENVE employees included. In those first years, some chose lightweight XC rigs one year and CX bikes the next, but it didn’t take long for the idea of a dropper post on a drop-bar bike to feel more like a need than a want. In 2014, the concept grew some legs in R&D, but projects and growth in our core wheel category kept us from making much progress. Since that time, gravel has rapidly evolved from the fringe to the mainstream, with more and more riders adding dedicated gravel bikes to their quivers and events to their calendars. 

As we built the outline for the “ultimate gravel dropper post,” it became apparent that an inverted dropper post design would allow us to build a better gravel dropper. Our primary objectives were low weight, unprecedented durability/reliability, and a low stack height to maximize compatibility with more riders and their nuanced fit needs. 

LIGHTWEIGHT

While the inverted seatpost design isn’t a viable solution for a longer travel dropper post, it is an excellent option for a short travel dropper and, above all else, a lighter weight, more efficient design. The G Series Dropper begins its life as two aluminum forgings that are then precision machined for maximum weight savings without threatening strength and durability. The inverted design also allows us to position the working internals higher than a traditional design and thus enables the use of otherwise dead space while adding the ability to cut or trim the post for up to an additional 50g weight reduction. 

BUILT TO LAST

As gravel riders, racers, and adventurers, we intimately understand that the last thing a rider needs is a dropper post related mechanical in the middle of nowhere. As such, we designed the post to be serviceable and adjustable with items that you’d likely have in your everyday tool kit. The dropper post uses a cable-actuated design and a fully sealed hydraulic cartridge that has been tested to extremes unlikely to be met by any of us over the course of our gravel experience. 

The inverted design also uses gravity to help ensure a long service life of the seals and bushings. As debris collects on the dropper’s stanchion, the actuation of the dropper wipes the stanchion clean, and debris is inclined to shed off the bike instead of potentially being forced into the seal and bushings. Another benefit of the inverted design is that if a saddle bag is required, you can run it with confidence, knowing that you’re not risking wearing the surface finish off the dropper’s stanchion, which can decrease seal life. 

To prevent side-to-side movement, the G Series Dropper Seatpost features brass anti-rotation keys vs. industry-standard plastic keys, which tend to wear out over time and result in a saddle that “knocks” when it rotates side to side.

MAXIMUM FRAME AND FIT COMPATIBILITY

The bike industry has primarily consolidated around a 27.2mm seatpost diameter, which is what the G Series Dropper Seatpost is designed around. However, there are quite a few bikes in the world, specifically mountain bikes, that use larger 30.9 and 31.6mm seatpost diameters. To accommodate this need, each dropper post includes alloy shims to achieve compatibility with these seat tube diameters. 

When researching the options on the market for gravel or short-travel dropper posts, we found that many dropper posts with traditional designs limited the range of riders that could use the post, usually due to the fact that the rider couldn’t put the dropper post low enough to achieve their saddle height. As such, we designed the G Series Dropper to achieve what is now the benchmark for stack height in the industry. 

A low stack height means that small riders or riders on a frame with high standovers who couldn’t run a dropper post before are now able to with the introduction of the G Series Dropper. We managed to achieve this low stack height by configuring the working internals of the seatpost to extend up through and beyond the seatpost’s saddle rail clamp. 

IN CLOSING

We believe that we’ve created a dedicated gravel dropper post that’s deserving of the G Series name. It achieves everything a G Series product promises, which is thoughtful design to deliver confidence in handling and an overall better ride experience.