Workout mode - Cadence too high

Hi all,

I use workout mode a lot.  When I get into a high power zone (say 350w, but the number is irrelevant),  I have to up my cadence tremendously. 

This gets to the point where I have to reach 110+ RPM, and often higher, to reach the setpoint.

I find that no matter the setpoint (it can be 10s @ 500w too),  I have always have to up my cadence like mad and this feels quite unconfortable.

I don’t know if this is b/c I come from a MTB background, but pedaling at this speed just feels wrong.  I sense there is more power available in my legs, but not more speed.  I wish the trainer would just apply more resistance so I could hit the setpoint at around 90-100 RPM.

Is this something that is adjustable?


What trainer are you using?

You could shift your gears

I forgot one important detail: I have a 27speed and run on the very last gear most of the time.  This is the problem I think.


Trainer is vortex smart.  Works very well in ride mode, but the peaks in workout mode are a real pain to reach.

Have you calibrated the trainer with the Tacx app?

What are the number of teeth on the gears?

What is the size of your rear wheel?

Yes, trainer was calibrated on first use and use about 20 times since then, but the problem has been there every since I started using Workout mode (and go in the higher watts).

The cassette is 11-32 and crankset is 44/32/22

Wheel size is 26’’
I feel like I just don’t have enough gears.

Max speed I have seen is about 40 kph.

Zwift only supports 700 wheels and you might not have enough gear.

1 Like

Not enough gears isn’t the problem, I suspect. 350 Watts resistance is 350 Watts resistance, and the Vortex Smart should be able to provide that (it goes to 950 Watt).

In ergo mode (as in the workout) the resistance should raise to the resistance set in the block you are riding, regardless of the gear you choose and the cadence you are running. It would be interesting to know what happens when you just keep pedaling at a certain gear and at a certain cadence, while the (asked for) resistance in the workout is raised, either in steps or as a upwards slope.

Does the actual resistance then “lag behind” the workout resistance (like being 10 or 20% to low at all values), or does it keep up at first, and then cuts of at a certain value?

I suspect the first (maybe due to your uncommon wheel size, which gives Zwift an unexpected cadence??). In that case the required setting (say 350 watts) gives a resistance of (for example) 320 watts. Going to a heavier gear or upping the cadence wont work - it will raise the resistance temporary, but then the trainer will “correct” it again downwards, till you are spinning as mad, and still have not the desired resistance. 

Interesting post Bertram.

For sure the Vortex is able to develop enough watts.  I have achieved peaks of over 500w so far, so the problem doesn’t lie there.

It is hard to answer your question but let me put it in my words.

Say the new block resistance is 350w. The resistance will increase fairly rapidly and in the beginning I will have to push harder and also increase cadence/gars (which is reasonable),  Then the closer that I am to the setpoint, the more difficult it becomes to achieve it (in a non reasonable way).  However I am able to get past the setpoint (although very briefly… 2 or 3 s). Once past it, I have to pedal faster and faster to maintain the same power value and I will normally drop below the block value because it becomes ridiculous to maintain.

When this happens, I just “feel” like the motor should apply more resistance (b/c I would actually be able to maintain the power), but it doesn’t.  

If the block value is 510w… same thing happens, but at 510w.

Thanks for your help.

I was not aware that Zwift is not compatible with 26’’ wheels.  Would I need a separate sensor?

First, in workout mode, you should not to have change gears - the resistance should go up and down automatically (if in ergo - mode). It does so slowly though, so if you just keep spinning, the resistance should go up to where Zwift thinks it is delivering the right (asked for by the workout) resistance. If it does not, you have a problem right there. You can raise the power needed for short periods of time, by spinning harder, or shifting to a heavier gear. But over time, Zwift will “correct” downwards.

As for the 26 inch wheel, and if a speed and cadence meter helps - hope someone from Zwift can answer that. If you can borrow a set, it might be good to try it, but buying them without being sure - might be a waste of money…(if you are close to Groningen, the Netherlands, you can borrow mine :slight_smile: )

Hi Bertram

Thanks a lot for your help. This hypothesis seems to be the most logical.  If I recap, with 26’’ tires, Zwift does not regulate the resistance command properly. The resistance it dictates to the smart trainer is too low, for reasons beyond my understanding.

I read 26’’ support is planned though (and other weel sizes too)

Do you know how I could get Zwift to jump in on this issue?

Hi All - I have the exact same problem.

I have just built a workout with 350w intervals. In the rest periods I have set 120w and in ERG mode my Tacx Vortex will adjust the resistance irrespective of my cadence.

However, it the 3 minute blocks that are supposed to be 350w I get a message saying more power and I too need to up my cadence to uncomfortable levels to get anywhere near the target. At 100rpm the ERG mode was only letting me achieve 310W at the most.

My wheels are 700c.


Cheer, Julian.

Hello, everyone!

Any developments on this issue? I use a Tacx Genius 2080 and have the same problem. In order to reach 240watts in a workout this morning, I was pedalling at a cadence of 115+.

I use a road bike and my wheels are 700c.

If anyone could help me, I would really appreciate it.

If you dont have or use ERG mode then you need to change the resistance using the ZML app (zwift mobile link) or the arrows on screen.

Thanks Gerrie! I was using ERG mode, though. It was a custom workout I built. I will try doing one of those workouts Zwift offers to see if I have the same problem.

Thanks again.