Road speed>cadence error in tour of london

Hi peeps, new to all this Zwifting malarky but having fun! :grinning:
However, last night I felt that the wattage seemed rather hard at times sending my HR sky high when riding well within my FTP. Also, when I looked at the ‘sprint’ finish I was spinning at 135rpm with a road speed of only 32mph… in a 50/11 I should be doing 48mph… (not that I could push it that hard in real life :wink: )
I thought all these non-workouts were in SIM mode?
Any thoughts?

EDIT: This is with a TACX Genius smart using ant+ & a garmin cadence sensor using ant+ on a powerful W10 gaming PC + the companion app on an android over BT.

How did you calculate the 48mph?

Yes all rides and races is in sim mode.

Hi Gerrie, you can see it here on:

that is what I thought.

Those calculations is for calculating the wheel speed when you are on a trainer but the wheel is spinning in free air.

To get that speed in real life or on zwift you have to generate enough power to overcome, gravity, wind resistance, drag and rolling resistance just to name a few.

According to
You have to generate 2446w to ridd at 48mph. Only a few pros can do that.

Hmmmm, but that’s not simulating anything?
My point is that (although I already said I cant generate that power) the road speed should be relative to my cadence and power. It’s as though the software isn’t reacting to my acceleration.
i.e I should have had a lower cadence as the unit increased resistance… but it didn’t… meaning that I was spinning out

This is looking more like a comms/sofware issue, does thePC rely on the cloud to provide resistance data? or is only the interactive scenery data. riders etc?

Yes the road speed is relative to power and sort of to cadence. what power were you generating in the sprint?

Are your trainer calibrated?

You can also play with the trainer difficulty slider if you need more resistance, but sadly it wont make a difference on a 0% incline.

Hi Gerrie
I call it a ‘sprint’ but I didn’t have a lot left after pushing so hard to maintain a well-sub-FTP :frowning:
I started to sprint but it maxed out at 400w and my cadence just wizzed up to 135. Basically I was spinning out so it prevented me from putting more power down.

Everything is calibrated and up-to-date, support even confirmed everything way fin their end with zero drop-outs?

So increasing the difficulty doesn’t work on anthing flat? Damn, I was going to use that if it did it again.

Do you pair your trainer as powersource uninf ANT+ FE-c and also as controllable ANT+ FE-c.

Hi Gerrie, yes, the Genius is Power & Controlled resistance over ant+FEC
I also have a cadence sensor over Ant+FEC (rather than use the Genius ‘estimate’)
All other software packages work fine… TTS4, Rouvy, VeloReality, RGT… just not Zwift.