Low Resistance in Training or FTP programs

Hello, I am new to Zwift and received my Hub yesterday. I set it up and logged in to Zwift for the first time, calibrated the spin down and had a free ride to check it out… all seems fine.

Next I wanted to do my FTP but I found that although I had the ERG mode activated the resistance seemed lacking and when asked to produce 140W I was spinning over 120rpm in the highest gear… strange, I tried a couple of training rides and the same thing occurred.

In the end I entered a race event and the resistance seemed fine.

Am I missing something?

BTW the Hub and the community support seem really great. Can’t wait to get into it!


Did you get to 140 watts? When in ERG mode the faster you spin the less resistance will be applied, kind of backwards from what you might think. If you spin slower it will get harder as the trainer adjusts resistance to keep you at the target watts, 140 in your example.

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The first time I tried the Ramp Test Lite I had the same thing. I ended up spinning out and gave up. I think I was a bit keen and needed to hold my cadence and let the trainer bring the resistance up to me. I’ve since done the Ramp Test and had no problems.


The same thing happened to my today. I felt like I was spinning over 120 until it got up past 160W? Did you ever figure it out? did pedaling slower fix the issue?
When you are doing the ramp lite FTP test, are you supposed to hover around the set wattage or are you trying to crank the entire time? Example, at 130W are you trying to see how much you can beat it, or just stay above it?

Hi @Steve_Chaisson

Welcome to the forum.

What trainer are you using, do you have ERG on.

Does ERG control the resistance in other workouts?

I’m using the wahoo kickr core and it does control the ERG. Even at the end of the test I had to stop as I couldn’t pedal any longer. From 50w - about 150w I was bouncing out of my saddle trying to spin fast enough to keep the Watts up. Maybe I started too fast and didn’t give the trainer a chance to catch up?

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Did you try to change to a different gear. ERG should engage at low speed.

yeah, I had it on the highest gears (hardest) and still spinning crazy. I can try to do test with the normal ramp test and not the lite. Should I try to stay at the watts the test has me at, or try to beat each level? Are the tests more about how finish, or how you do throughout?

With ERG you won’t be able to go over the target power.

Try the normal Ramp test it start a bit harder.

But you should try to find the correct gear to ride at low power at about 70-90 rpm. Some trainers won’t activate ERG if you are producing to much power.

ok, so it sounds like that wasn’t normal behavior. I will go back and do some testing to see where the problem is.
Thanks for your time!

Andrew has it.

I had the same “problem” first time around. I was spinning faster and faster trying to get the watts up until it was impossible for my legs. I had to learn to trust the trainer and let it increase the watts. Get your happy cadence and give it a while to increase resistance. It’s not instantaneous at each interval/banner. I’m guessing some trainers react quicker than others too.


I remember reading somewhere that while doing the warmup and cooldown sections of the workout ERG mode will be on but as soon as the FTP test starts it deactivates which makes sense since you are trying to determine what is your max sustained effort which will then be used as the baseline to set the power targets on future workouts which use ERG mode. You will have to use your bike’s gears to set the resistance.

For the ramp test ERG will be on the whole time.

What you describe is the 20 minute test, where the 20 min section will have ERG off.