Just some honest feedback after a month+...

First off, I want to express my gratitude for the product Zwift has produced; I’m sure the programmers and support staff work DILIGENTLY and TIRELESSLY to improve our (the customer’s) riding/training experience (I used to be in IT, so I can imagine). That is much appreciated and I thank you!!

Having said that, there are still known glitches in the software, some of which are currently being addressed by Zwift. For instance, the wheel slippage issue with the Kinetic Rock and Roll trainer is being worked on and that is also much appreciated.  My particular setup is the Kinetic Rock and Roll trainer along with the ANT+ dongle and Cateye ISC-11 Speed/Cadence Sensor. I’ve read a lot on the forum boards where people’s data arbitrarily drops out and their issue was pretty much resolved by placing the dongle right underneath the sensor. I’ve had my configuration set up like that from day 1 with a long USB extension cable (actually 2 connected together) and the ANT+ dongle right underneath the sensor, no more than a foot away.

Again, as much as I appreciate the job the Zwift crew is doing, I’d like to voice my fairly stern displeasure with what I’m experiencing, which may be isolated to my setup, but might also be affecting other riders without Smart Trainers, i.e., a “basic” setup using zPower.  I’ve been riding Watopia and Richmond for over a month and I’m just now starting the Beginner FTP Builder training circuit. I’m just gonna say it and I’m sure it’s nothing the Zwift staff doesn’t know; what I find very disconcerting……VERY DISCONCERTING……is when I’m pedaling my Gluteus Maximus off and I see my RPM and Watts momentarily spike to 0 (zero) and it affects my results. As a rider population, we are a “goal oriented” group. When I see that my star isn’t completely filled in after a stage of the workout when I KNOW I met the metrics of said stage, I’m a little peeved.

From a hardware/software perspective, I think I’ve done everything Zwift has recommended to prevent this from happening:

  1. I’ve removed all devices away from the ANT+ dongle that may be interfering with my WiFi signal to include my wireless mouse, iPad, and cell phone, though I don’t think these are causing the issue.  Others seem to have their iPad/cell phone within easy reach and using them while riding.
  2. Before riding, I exit any background apps on my PC that may cause conflicts with the software, e.g., I put AVAST in “Silent gaming mode”.
  3. As previously mentioned, the dongle is right underneath my Cateye sensor unit no more than 12" away.
  4. I even ordered a new USB extension cable (due for delivery next week) to replace the two I have connected together, thinking there may be an issue with lost connectivity/signal from the ANT+ dongle to my PC.

So question……are people having these issues with sensor units other than the Cateye ISC-11, like the Garmin unit? And what specific model Garmin unit (or ANY other sensor unit for that matter) do y’all recommend?

In summary, I want this to be a gratifying experience; I’m sure that’s Zwift’s #1 goal for this system and for EVERYONE involved!!  When these issues continue cropping up, it’s VERY frustrating and personally distracts me from an enjoyable workout. I don’t mind spending the money to make this work with my setup…I just need assurances from Zwift that I’m not going to throw money down the drain on equipment that isn’t 100% tested and/or compatible with this program. I look forward to any suggestions you may offer.

My best regards to everyone at Zwift!!

Replace the battery?

just so you know, sometimes this happens with actual power meters and other sensors (e.g. speed, cadence, etc.) while riding outside and recording the data via a Garmin, etc. 

this is the nature of RF, whether it is ANT+ or BT. a temporary loss of RF or failure to receive a Tx. these things happen.

try not to let a “star” ruin your day. if you did the work, you did the work. if you hit your targets, you hit your targets. you know that and you don’t need a star to tell you that.



Hi Joel!

Thanks for the fair and excellent feedback and criticisms. The key here is the Cateye ISC-11 speed/cadence sensor.

We are seeing reports of it not working properly and we are in the midst of testing it in-house (it took us a bit to get one) to determine if this is something that is easily reproduceable and what may cause it.

Right now, we know that both types of Garmin sensors work and that the Wahoo Blue SC also works. The fact that the Cateye may exhibit problems is something that we hope to fix on our end.

We do thank you for your continued patience while we try and solve this issue! 

Greetings Eric,

Thanks for all that info and the great news that Zwift has isolated a problem with the ISC-11 sensor itself!!  You mention both Garmin sensors work…I’m going to assume you’re referring to the GSC 10 sensor and the newer speed/cadence sensor pictured below: If this will yield better and more consistent results than the Cateye ISC-11, I don’t mind changing out one bit.

Do you have an estimation of when the Zwift support staff will finish their tests on the ISC-11 and know if there’s a “fix”?  If it’s just going to be a week or two, I can hang on to the ISC-11 and just “suffer” through the inconsistencies for the time being and save $70. :slight_smile:

Again…thanks for the awesome support!!


Hi Joel,

I ran across many of the same issues with my setup, despite using a Garmin sensor unit (gsc-10). I solved the issue by using an “active” USB extension cable. The ANT receiver struggles to send data with any cable over 6’. A powered cable uses the power from the port to boost the signal. My ANT receiver now sits 5+ feet from my bike and picks up perfectly.

The cable is technically known as an Active Extension/Repeater cable. I bought a 30ft one from Monoprice for less than $10.

Good luck! It’s worth the hassles to sort out your setup.

Yes Joel has the best setup.

USB cables has very short lengths. So linking two together you probably exceeded the maximum length.

  • USB 1.1 maximum length 5 meters  with devices operating at Full Speed (12 Mbit/s), and a maximum length of 3 meters with devices operating at Low Speed (1.5 Mbit/s)
  • USB 2.0 provides for a maximum cable length of 5 meters for devices running at Hi Speed (480 Mbit/s)

Information provided by https://en.wikipedia.org/wiki/USB

Jeff, Gerrie, et. al.,

Thank you kindly for the feedback!  I got rid of the (2) cables plugged together and got a cable long enough to stretch from my computer to my bike.  I will consider a powered cable (per Jeff’s response) if this proves to give me consistent “faulty” results as well.  I think Michael pretty much nailed it though, with his post when stating that this stuff is electronics…the signal will drop from time to time based on MANY factors.  I just have to accept that fact and keep pedaling! And to Dave’s response on the battery, it might be a good idea to keep a fresh battery in the transmitter on a monthly or bi-monthly basis; pain in the butt, but would eliminate that variable.

Right now I’m just trying to get over this minor bout with some flu symptoms…_ thankfully _ I’m on the downhill side of it.  I HATE being sick because I CERTAINLY don’t feel like riding.  Hope to be in the saddle early next week.

Take care y’all…Ride on!!