Hi,
I purchased a Runn sensor and recently installed it on my new treadmill using 3 sensor stickers spaced 30 inches apart.
Here are the issues I’ve encountered:
When I set the treadmill to 8 km/h, the ConfigurEZ software shows 7.3 km/h. At 12 km/h, the ConfigurEZ software displays 10.8 km/h.
When I connect the sensor to Zwift and my Garmin (as a foot pod), and set the treadmill to 12 km/h:
Zwift accurately matches the treadmill speed at 12 km/h.
However, both the ConfigurEZ software and my Garmin watch display only 10.8 km/h (pace: 5:35–5:40/km).
To further test, I set the treadmill to 13.5 km/h (pace: 4:25–4:30/km), which aligns with my outdoor tempo pace in terms of effort, running form, and heart rate. Zwift—with the Runn sensor—also displayed 13.3-13.5 km/h, which matched the treadmill speed. However:
ConfigurEZ and my Garmin watch displayed 11.5 km/h (pace: 5:15–5:20/km) - not possible with my feeling.
This discrepancy is significant, as I clearly exerted tempo-level effort consistent with my outdoor running experience.
I often run at a pace of 5:15–5:40/km as part of my daily or easy runs. I am confident that the speed readings from ConfigurEZ and my Garmin watch (which are connected to your sensor) are inaccurate, as running at these settings feels noticeably harder than usual. My perception aligns much more closely with the treadmill and Zwift readings.
Could anyone help me understand why the speed in Zwift matches the treadmill but differs significantly from ConfigurEZ and my Garmin watch? What went wrong? I purchased the Runn sensor specifically to obtain more accurate data than my watch, but these results have left me feeling confused and disappointed.
Thank you,
Are you confident your treadmill speed (not the display but the actual belt speed) is accurate? The RUNN calculates speed between t fixed points with the stickers.
Does adding more stickers change the readings? Asking as the foot strike slows the belt some. Sorry I cannot be more helpful.
Hi, thanks for your reply. I used 4 stickers.
I didn’t claim that my treadmill is accurate, but I’m confident in assessing my running effort. My easy pace is about 5:15–5:30/km with a heart rate of ~135–140 bpm, which translates to a speed of 11–11.5 km/h - outdoor running.
I tried to match the speed shown by the Runn sensor on ConfigurEZ and my watch. To achieve 11 km/h on the watch and ConfigurEZ software, I had to set the treadmill to 13 km/h (pace: 4:37/km on the treadmill).
I’m certain this pace closely matches my tempo effort, which wouldn’t be possible if the Runn sensor were accurate.
There are two ways of calibrating the Runn. One is via Confgurez and the other is via Zwift. The two are independent of each other.
By default the Runn is factory calibrated. However the Configurez calibration is there is you notice a discrepancy between the reported speed of the Runn to the reported speed on your treadmill console. That way you can calibrate the Runn to the treadmill speed so they match.
Likewise in Zwift you can calibrate the Runn if the reported speed in Zwift is not matching that of your treadmill console.
The only way you will know which is accurate is to manually measure the belt speed of your treadmill against the reported speed on the console. Simple enough to do. Ideally do it when running as depending on the quality of your treadmill the belt speed can slow by up to 1km/h when under load.
Your gamin watch will also be innacurate for measuing pace. It uses the accelerometer to measure which is effectively your arm swing. Your arm swing does not vary much in say half a km/h difference so it will never be accurate in that sense.
Likewise the Runn itself has never been great for reporting pace when it’s been calibrated in Zwift. Say you calibrate it at 12km/h as your normal pace. If you go a few km/h above or below this then the Runn struggles to maintain accuracy. Again how much by is totally dependant on the quality of your treadmill.
I’ve googled and the best Kingsport treadmill I can find only has a 3hp motor but thats peak. So likely to be either between 2 and 2.5CHP. This is on the weaker side for a treadmill motor and therefore you will see a lot of bouncing of the reported speed from the Runn as you belt will be stuggling to maintain a constant pace. The bigger the motor to better it is able to maintain belt speed.
When it comes to comparing effort on a treadmill to real life there is generally a significant variance. On a treadmill you have no weather variance such as wind. You will generally be hotter on a treadmill so core body temp will be higher and affect perceived effort.
Some are better runners on a treadmill than real life and others vice versa.
And remember we have good and bad days. For all my treadmill experience I can have a lot of variance in how I feel despite running the same pace and distance. My average HR needs to be only up by only a few beats average over a 10k to make a run feel totally different. 140 might be comfy. 145 might be a real struggle.
So you have a decision to make in terms of do you want your Zwift pace to match your treadmill or do you want Zwift to report the pace your belt is moving at?
Thank you very much. This treadmill has a 4.5 HP motor, yes, peak, but it is powerful and stable.
I have also run on many bigger and better treadmills at gym centers, so I can confidently say this treadmill is stable and powerful.
I mostly run outdoors at paces ranging from 5:30 to 3:50/km, using the treadmill only about 30% of the time due to a busy schedule.
Because of this, I can clearly feel the differences in stride, cadence, and running form. I have used this treadmill about 6–7 times, and my feeling is that it runs slightly slower than outdoor speeds. For example, if I set the treadmill to 12 km/h, it feels similar to running at 11.5 km/h outdoors. However, this discrepancy is not as large as what the RUNN sensor shows on ConfigurEZ (10.2 km/h, cadence: 179 spm).
I also used an HRM Pro Plus, which tracks pace and distance, and it showed 11.7 km/h with a cadence of 188 spm.
I’m not saying which one is accurate, but I trust my running effort and running form. While “feeling” is never completely accurate, I believe it’s 85–90% correct.
I’m not much of a runner so don’t have Stuart’s experience of treadmills or running. I do however have a RUNN.
I also suggest you measure the speed of your treadmill, using the RUNN and belt revolutions, and compare it to the reported treadmill speed. When I did this I found the RUNN was very accurate at reporting the belt speed and the treadmill not very accurate.
One area where I differ to Stuart is you don’t need to be on the treadmill to confirm whether RUNN is reporting the correct belt speed, measured against your count of belt revolutions to time exactly 1km or 1 mile whichever you choose. But Stuart is absolutely correct that almost all but the most powerful treadmills (belt speed) will slow down when you are on the treadmill but at that point your RUNN will report a lower belt speed. [ test is set treadmill to your chosen run speed using RUNN, not on the treadmill, then carefully jump on (without changing treadmill speed control ) and see what new speed is reported by RUNN.
One thing some people have done, incorrectly in my opinion, is to calibrate the Runn to match their treadmill speed. If you have done that reset the RUNN to factory setting - there is no good reason to calibrate the RUNN ( unless you wish to run at treadmill speeds which may be inaccurate ) it is precision engineered to do only one thing very well - measure treadmill belt speed.
As per Ian’s suggestion you 100% need to measure your belt speed. This might satisfy your mind in terms of your difference in perceived effort.
But like I’ve said comparing effort on a treadmill compared to outdoors is difficult as the environment is totally different.
And if you’ve only done 6 or 7 runs it’s a little early to be fully convinced. Each treadmill can be different and I’ve had numerous customers complain that their new treadmill feels slower or faster than their old one for example. When measured it’s fine, it’s just percecption.
The reason I suggested calibrating under load is that you seen determined to want accuracy of pace compared to outside running so you need to have the speed as close to accurate as possible. If you calibrated without load your 12km/h might then be 11.5km/h when running. Calibrate under load at 12 and you know its 12.
And yes the only reason to calibrate the Runn in Zwift is if you can’t cope with the reported speed of your treadmill not matching that of Zwift.
It all depends on what you want out of the experience.
Thank you very much. I already conducted another test using the HRM Pro Plus and a footpod at my easy run effort (11 km/h as indicated on my treadmill and two other treadmills at the gym center). It seems very close to my outdoor running effort (a difference of 15 seconds/km, corresponding to 10.8–11.2 km/h, which is acceptable). However, the Runn sensor showed 9.8 km/h. That’s fine, I’ll let it be. I plan to do 30% of my easy and recovery runs on the treadmill, use Zwift just to see running data easier (heart rate, pace, distance, cadence), with the remaining 70% being outdoor runs for tempo, interval, and long runs.
However, apart from speed, the cadence data from the Runn sensor is completely incorrect. I can say this with 100% certainty. Anyone who frequently monitors their running cadence will notice the data from the Runn sensor is not accurate—or at least not in my case. I know for a fact that I run at 188–196 spm, but the Runn sensor shows 170–174 spm.
The incline measurement is also inaccurate. I used my phone and a clinometer to check the incline, and both showed 1.4–1.5 degrees, which does not match the Runn sensor’s reading of 0.6 degrees. I can even see the incline difference with my own eyes without needing to measure it. This is the incline I’ve set up permanently on my treadmill to compensate for wind resistance.
I was hoping that the Runn sensor would provide accurate data for speed, cadence, and incline. However, it seems I’ve wasted my money.
Apologies for not reading the entire thread, but just based on your picture, the sticker placement for your Runn sensor doesn’t seem ideal. For the best results, you should aim to space the stickers approximately 12 inches apart.
From my experience with the Runn, it’s crucial to first determine the actual length of your treadmill belt (most “running” belts are typically between 120 and 130 inches). Then, calculate the equidistant spacing to place as many stickers as possible. For example, on my F85 treadmill with a belt length of 126 inches, I use 11 stickers spaced about 11.45 inches apart. If the Runn is properly installed -the speed is highly accurate! Btw, I never had issues with the incline data, I use a digital level.
Cadence data from the Runn sensor is widely recognized as being inaccurate. Instead, I rely on the cadence and all the running dynamics data from my Garmin HRM Pro Plus, which provides excellent accuracy and a lot more data.
How old or new is your walking/running belt? Has it been lubricated regularly?
If the belt is old, damaged, or of poor quality, it may not slide properly with each step, creating excessive friction and slowing it down (this is huge with home treadmill).
Thank you. I will measure and re-arrange the stickers. Based on the Runn instructions, “the distance between the stickers should be at least 18 inches or more.” However, I will try again.
My treadmill is new, with only 60 km of usage and already lubricated.
I know it’s a pain to measure and place those stickers, I just changed my running belt! but it’s well worth it to take your time. Note: I do glue with Loctite each sticker
The recommendation for sticker placement from NPE is based on an average of the best results from testing across a wide range to treadmills.
There is however no right or wrong number of stickers and the ‘ideal’ is totally dependent on your treadmill.
Remembering that each time a sticker passes the sensor it provides a reading so this is where Zwift is sent speed data.
If your treadmill is able to maintain a constant belt speed then each reading will be the same and therefore your reported speed in Zwift will remain constant.
However for a poorer quality treadmill that struggles to hold belt speed with each foot strike then you will see your speed constanctly bouncing up and down.
This is where less stickers is better as the Runn reports your speed less frequently and therefore your Zwift speed changes less.
Cadence is a tough one as how do you know what right and wrong without actually manually counting. And depending on many factors our cadence can vary at the same pace. Wind, gradients, surface and fatigue will all cause our cadence to differ.
And comparing your in real life cadence with treadmill cadence is a definite no no. Tests have shown this.
Remember that the Runn is giving your cadence based on a vibration rather than a visual recording. It can be affected by where on the deck you strike.
With regards to the incline, this is where it needs calibrating to your treadmill. Some treadmills are 1 or 2% inclined by default so whilst the treadmill console may say 0 it’s actually 2% on the deck. As mentioned you need to get the deck of your treadmill level and then calibrate the Runn to this. Also check that your treadmill increments in percentage rather than levels.
It might have levels of 0-16 but this does not actually mean it’s 0-16%
It’s fair to say the 3 of us are experienced runners and shouldn’t really expect that the Runn will be as accurate as perhaps you might wish. By sheer design based on the way it works you can see how it might struggle. It was designed to be more accurate than a footpod but was always a cost effective way to make a dumb treadmill a smart one. With the advancement in smart treadmills the Runn is effectively on borrowed time.
