Wireless electronic dropper posts have been in existence since 2017, when Magura's Vyron post debuted. RockShox released their Reverb AXS dropper two years later, and in the years since it's become the most commonly seen housing-free option. There's just one problem – there's still no 200mm version, and no clear answers as to if / when we'll see one. That hole in the marketplace is slowly starting to fill with alternatives, including the TranzX EDP01 reviewed here.
EDP01 Dropper Details
• Travel amounts: 150, 170, 200mm (tested)
• 30.9 or 31.6mm diameters
• Weight: 767 grams / remote: 52 grams
• Two-year warranty
• MSRP: $499 USD (includes battery + remote)
• More info: na.tranzx.com
The EDP01 is available in 31.6 and 30.9mm diameters with either 150, 170, or 200mm of drop. The post is powered by a rechargeable 7.4 volt battery, and the remote uses a CR2032 battery. TranzX claims the post can be activated 6,000 times before needing a charge, although my fear of being stuck out on the trail with a non-functioning dropper caused me to charge it every handful of rides just to be safe.INSTALLATION
There isn't any performance aspect of a wireless dropper post that makes it a must-have over a cable-actuated version, although the ease of installation does count for something. There's no cable and housing to deal with, and getting it up and running is as simple as putting the post in the frame, pairing it with the remote, and hitting the trail.
TranzX touts the post's short insertion depth, and while it is low at 290mm, the total length of the EDP01 from the bottom to the rails when fully extended is 545mm, while a 200mm OneUp dropper measures 530mm – the distance from the bottom of the collar to the seat rails is longer on the EDP01, due to the motorized mechanism. That means that to achieve the same seat height, the TranzX would need to be inserted further into a frame than the OneUp.
The post uses a one bolt design to clamp the seat into the rails, with another bolt at the front of the post that's used to adjust the seat angle. It's a convenient system, and I found it to be quicker to use than some of the more fiddly two-bolt options out there. PERFORMANCE
Initially, the EDP01's return speed was on the slower side, that is until I increased the air pressure in the cartridge to 350 psi (the maximum recommended) via the air valve on the bottom of the post. That helped speed things up, and while it still doesn't extend as quickly as a RockShox AXS, that faster return rate was an improvement. The effort it takes to lower the seat is fairly average – it's not as silky smooth as a BikeYoke, for example, or even the aforementioned Reverb AXS.
The good news is that it didn't develop any squishiness during the test period – the cartridge is still going strong. TranzX also sells replacement cartridges separately, and should an issue arise they can be swapped out in a matter of minutes. They may look and function similarly, but TranzX is adamant that the cartridges are not manufactured by Wintek, the company that makes the internals for many other dropper posts.
The remote lever is easy to access, and while it may not be the most elegant looking component, I don't have any complaints about its functionality.
As for the run time of the post, I did have the battery die on me partway through a ride. I'd left the battery installed during a three-hour drive with my bike on a vertical hitch rack, and then forgot to check its status before my next ride. It's a good reminder to take the battery out when driving longer distances; otherwise the road vibrations can potentially cause it to constantly try to pair with the remote and run the battery down, at least I'm assuming that's what happened.
That was the only hiccup I experienced, although I'd be tempted to purchase a spare battery to bring along on mega-rides, just in case (they're available for $49 USD). It's wishful thinking, but it sure would have been nice if the EDP01 battery was compatible with SRAM's AXS batteries, and vice versa. ISSUES
After a few months of use the post started making a knocking noise when the seat was lowered and I went over chattery sections of trail. I eventually narrowed it down to the nut that attaches to the cartridge at the base of the post. That had loosened slightly, and was allowing the cartridge to move up and down and make a racket. I snugged it down, and it's been smooth sailing since.
Very easy installation+
No need to worry about cable routing or contaminated housing+
Easy to disassemble for basic servicing
Going wireless isn't cheap-
Not the fastest return speed-
Heavier than cable-actuated posts, even when factoring in the weight of cable + housing