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What is the difference between RepOne Sensor and RepOne Tether

RepOne Sensor, the Velocity Based Training tool we've been selling since 2020, is now RepOne Tether. The verbal distinction in itself is significant, which I'll get into shortly, but the lack of external change betrays the huge internal re-engineering effort that's taken place over the course of the past two years.


We've been quietly shipping RepOne Tether from our Jacksonville office for a week now. The latest firmware, v0.8.22, updated all units ever shipped with improved visuals among other features, and also supported the new electronics shipping quietly inside each black nylon shell since November 8th. I'll get into the majority of the changes now, save for one special aspect of our giant engineering effort that we'll announce in a few weeks.


Under the Hood

This is far from the first iteration of our internal hardware, but definitely the most significant. Technically the engineering for RepOne Tether started shipping in 2022 with big upgrades to our spindle, and the new electronics complete the transition. Details on the new electronics, and the features they enable, are detailed below.



Current customers know RepOne Sensor was particular about what can and cannot charge its battery. RepOne Tether did away with that problem, enabling charging from any USB-C cable and any USB port, and even supports fast charging from some sources.


Battery Life

When you forget to turn off a device, it's inconvenient if it dies before you see it next. Because RepOne Sensor fell asleep and woke up from tether movement (or lack thereof), we had to keep a lot of the electronics sipping power so we didn't miss a thing. RepOne Tether solves this by allowing almost the entire device to shut down after 20 minutes, and is smart enough to wake itself up simply when picked up. In our testing, this extends battery life almost 7x when left on, and 2-3x when in use. Some of these features are coming soon in a future update.


Accuracy and Reliability

We can confidently claim that RepOne Sensor was the most accurate LPT on the market, regardless of price. RepOne Tether kicks that up a notch. We've spent months of dedicated engineering testing a new method of encoding that is so accurate, it enables us to support metrics we couldn't confidently ship in previous iterations. Yes, that means Force and Power are coming to RepOne Tether.


More Memory

RepOne Tether now has twice the internal flash storage as RepOne Sensor. This might sound like an iterative change, but we've been blocked on certain features for years due to this limitation. Features like simultaneous concentric/eccentric measurement, multiple view modes, and asynchronous Bluetooth communication are a few examples. These are all features we're working on now for RepOne Tether.


3D Features

All RepOne Sensor units shipped since day 1 come with a patented, one-of-a-kind sensor suite that measures tether angle for metrics improvement. We've been limited in expanding our suite of 3D features because of noise that limits the spatial accuracy of this unique sensor. RepOne Tether comes with an improved sensor package that essentially eliminates this noise, allowing us to support higher resolution 3D features in future updates.



RepOne Sensor has shipped with LEDs since 2021, but they've been of limited use due to technical implementation issues. Those have been rectified, and in a future update RepOne Tether will support LED notifications for battery status, Bluetooth connection status, on/off state, and much more.


More Accurate Battery Readings

Battery charging and battery state monitoring have been pain points in RepOne Sensor in the past. Combined with our improved USB-C charging, our improved battery readings give the user much more confidence in the up-time of their new RepOne Tether. 


More Than a New Name

Apologies in advance if this comes off as cryptic, there's a lot more to the story that we won't be able to reveal for another few short weeks. 


We've been slowly improving RepOne Sensor since we first shipped at the dawn of the pandemic, and we plan on continuing to do so for the foreseeable future. What makes the transition to RepOne Tether different is something we started working on almost two years ago now.


Our vision has always been to make modern training methods accessible to all. Velocity Based Training is a step in that direction, and where RepOne Sensor symbolized that first step, it's not an exaggeration to say RepOne Tether is symbolic of the rest of the marathon.


We appreciate your support thus far, and are excited to show you what we have in store.