Pebble Pounder: Power vs Cadence

I am fairly new to Zwift, and after a few rides around Paris and Watopia I decided to try the Pedal Pounder Training Plan… I was a roadie for years, then took a few years away from being on a bike and this past spring I got into mountain biking - I’m looking for something to help get me in better shape through the winter. Anyway… I’ll post my setup below but the issue that I’m having is that while doing the first 2 workouts I’m inconsistent with power vs cadence. For example if the app is telling me to use more power (185K/w) its at a lower cadence ~85rpm… If i pedal faster, it’ll increase the power, but then tell me to slow down the cadence… if I slow down the cadence to the appropriate range, its telling me more power. I don’t understand how to find that balance… Is it a setting or configuration I’m missing somewhere to set a baseline? It just seems like hitting both are unattainable (or does that come with more riding and strength?

As for my setup its probably not ideal, but it works:

  • Tacx Vortex Smart Trainer
    Updated firmware and calibrated through the Tacx App, the white line is right in the center.
  • Giant Talon Hardtail bike:
    I’m using a 29" training tire on back, selecting 700x23 during pairing as thats the closest option.
    1x9 drivetrain (front is 32t, rear is 11-42)

Now, I know from the freerides I did my first few days the trainer was adjusting the tension based on the terrain - harder to pedal uphill, easier down, etc, so I was shifting as if I was on the street/trails. I don’t feel that happening during the workouts - I’m guessing thats by design? I’ve tried shifting to find that magical sweet spot but end up staying in 32x11 most of the time, any of the bigger rear gears and my cadence goes way up and power drops, I’ll pretty much do that for the cool-down period

I’m not sure if I’m doing something wrong or should tweak my setup so any advice would be welcome!

Hi Howard @HLS811, and welcome to the forums! I hope some bike techy person chimes in here too, but since you haven’t gotten a response yet, I thought I would let you know about my experience. I have done the beginner FTP Builder twice and just started the Build Me Up plan, so I am familiar with the cadence/wattage conundrum. I have been able to switch into a gear that works for most things. You mention that when you pedal faster the power increases. Can you shift to a bigger gear in the back at that point? That’s what I do, and it seems to work. You mention that a bigger gear causes the cadence to go up and your power to drop - is there no sweet spot? It seems like when you have the correct cadence and not enough power, then you need a harder gear, right? The thing I can’t do at this point is pedal at a low cadence and low wattage while standing, which I apparently need to get a bunch fitter to do. Currently I am heavy enough that when I stand, I automatically put out more watts than the plan wants in a gear that allows me to pedal slowly. I hope that helps, and I hope you get it figured out! Ride On!

Hi Beth - Thanks for the response! I think maybe what I should do is on of the FTP tests and see how I rate there. I sort of just jumped into trying the workout plan and didn’t really look to set any benchmarks for myself.

As far as the gears go, my bike is “only” a 1x9 - a single cog at the cranks and 9 cogs in back - I will ride with it on the smallest rear cog, which is actually the “biggest gear” - so unlike a road bike with 3 cogs up front I can only shift so much and that may be part of the issue for me. On a mountain bike thats perfect, trying to simulate a road or gravel bike on a trainer, not so much.

If I go to a bigger cog in the back theres less tension and I start free spinning - thats why the cadence goes up so much for me and power drops (thats how I’d have it trying to climb a steep hill).

Pedaling at low cadence and low wattage while standing is hard on a bike inside because you don’t have any resistance and you’re off balance, keep practicing the technique though, thats what you’d need to do out on the road when climbing and it’ll be so helpful to learn! Keep at it and you’ll get it!

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Hi Howard, Yes, indeed, I’ll bet the limited number of gears is the problem then. Lots of people suggest that you do the FTP test before starting a training program, so I eventually did that. I had ridden around enough before trying a training program that my FTP as set by Zwift turned out to be pretty accurate - and when I took the FTP test the first time, I sort of freaked out and ended up with a lower score than I had started with. That was depressing; but also inaccurate, so I switched it back and went from there. I think the training programs are wonderful and have made a bit of progress, so I’m pleased - and I can even stand for a few seconds at a time now, so I figure I’ll get there some day!
What will you do if your bike doesn’t have enough gears to do what the training program wants you to do? I hope you find something that works for you!

I’m going to try and do the FTP tonight and see how that goes.
I’ll keep the setup as it is, I may not get the most out of it because of the bike, but I was still working up a good sweat and my legs are feeling it… 30-60 minutes on any type of bike is still more exercise than sitting on the couch. :slight_smile:

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Hey Howard, my first post here, check and google ERG mode and Zwift… being a smart trainer, in ERG mode, it’ll adjust the power accordingly to your cadence… if I’m understanding your situation right, this would solve your problem.

Thank you! I have seen ERG listed and it seems that when choosing individual workouts theres a button to enable/disable ERG mode, but I don’t recall seeing it when doing a plan… I’ll have to dig around a bit and see if thats an option.

as its been mentioned, the ERG should limit the power required to be produced. Therefore you can adjust cadence to suit and the smart trainer will do its thing to maintain the required power.

running a 1x9 should be absolutely fine, so dont worry about that.