Incorrect speed readings from Wahoo KICKR

Assuming that the KickR is similar to my Neo, you need to manually set wheel size in the watch. Default is Auto. That might get you close, but not necessarily correct.

The Neo size is 2133mm. KickR might be the same, but maybe not. It should be documented somewhere.

I can't see an option to set the wheel size in the watch. And, as said, speed has never been an issue for years and years, apart from recently, without any changes to my settings. In fact, the speed readings from the same training, as synced with Garmin Connect directly through TrainerRoad show the correct speed.

Where is the speed coming from? What have you got set in Sensors and Accessories? I have a Tacx Vortex Smart connected to my F6 as a combined speed/cadence sensor that I've had to set a manual wheel size.

If you are getting a speed reading on the watch you have a sensor connected. You need to check that. Go to Settings, scroll to Sensors and Accessories, locate the spd/cad connection for your Wahoo - you might have to be connected to edit it.

Wheel size is an attribute defined for the speed sensor connected to the watch.

Trainer Road is simulation software. The watch does not know of any simulated gradients and associated speed changes and in erg mode your wheel speed can be just about anything, depending on gearing, while the sim software might have completely different ideas about your virtual speed. At last in Zwift, which is my software of choice, there is no earthly reason for speed and distance to match between the watch and Zwift. I can't speak for Trainer Road, but I expect similar behaviour, possibly.

I am have the same problem since the last firmware update. However it only occurs in training sessions in Zwift where there are power limitations i.e warm ups  at 80 watt and you’re in big cog little cog with a cadence of 80rpm which in normal circumstances would equate to a speed of about 35mph (56kph) my fenix 6s pro speed reading  hovers around 12.2 mph (19kph)  and won’t go above that  when you increase the cadence. Speed readings seem to be governed by power output. I have done all the usual checks,  wheel  size setting  etc and they are all correct. 

Virtual speed from Zwift is likely to be different from wheel mounted sensor speed. FWIW I’ve just done a workout on Rouvy where the Rouvy speed is always different t to my watch speed. I’m watch speed comes from the wheel sensor. On Rouvy the speed comes from whatever Rouvy decides depending on what the virtual route is doing - uphill, downhill, flat etc.

8983289 said:

However it only occurs in training sessions in Zwift where there are power limitations

Zwift isn't using the speed calculated by your wheel diameter - it's virtual speed based on it's imaginary hills / slopes etc.

If you want to see the 'true' speed then record on your Garmin device at the same time as Zwift, you'll get the true 'speed' based on your wheel revolutions multiplied by wheel circumference - it'll be far lower.

(obviously speed on an indoor bike its'n really speed, as you are not moving)

The speed readings I referred to is on my Garmin and not on Zwift!

c

8983289 said:

The speed readings I referred to is on my Garmin and not on Zwift!

Fine, but why not say that? You just spoke about Zwift - we're not mind readers here.

Being as this query refers to problems with a Fenix 6s speed readings when using a wahoo kickR I would of thought that would be implicit try reading the whole thread