Workouts - Different Gears = Different Results?

I tried searching for this but just got a million results unrelated to the problem.
So I did an SST medium workout using a 50x19 (although theoretically it’s a workout so shouldn’t really matter what gear I’m using right?) and completed it no worries; tough but manageable.
A few days later, I tried the same again but inadvertently left my chain on the 28t cog from my warmup.
I couldn’t even get half way through the workout.
Now, to be fair, it’s quite possible I was suffering from a bit of overtraining but if we assume for a minute that that isn’t the case; is it AT ALL possible that different gears could yield different results in workouts?
All else was equal; I naturally spin at about 100 to 105 rpm so kept cadence consistent too.

Hi @Adam_Slee_VZT, what type of trainer are you using, is it a smart trainer with ERG mode? If so, then the gearing will not matter if you are in ERG mode. Cadence however, will have an impact. Higher cadence should feel easier and lower cadence will force the trainer to add resistance to hit the wattage target.

Hi Mike, thanks.
Yes it’s a smart trainer and yes I use erg mode. Thanks for your confirmation; yes I understand regarding cadence as if I slow much below 95 my heart rate jumps and I burn out.
Just curious whether anyone else had experienced this.
I only ride fixed gear in real life so tend to just use a single gear whatever kind of zwifting I’m doing.
Going to try the SST again now and see what happens…

I would suggest that during the recovery intervals, or if the workout doesn’t really have any recovery, but does have a lower power zone interval, that you reduce your cadence a bit, and then when the more difficult interval is about to start in the last 2 seconds bring your cadence back up to 100. This should help you “get on top” of the gear as the resistance changes and it won’t feel like as large of an increase in effort.

OK, so I just completed the same workout on the 50x19 without a hitch. I’ve done the same workout about 100 times so I can only assume that either I was having a really bad day or there is indeed some disparity in the ERG / Zwift / Trainer / Gearing system.
I guess the acid test will be to try again next time in the lower gear and see if I can repeat the results…

It is my understanding from watching multiple youtube videos from people regularly testing trainers that having your bike in a middle to lower gear allows ERG mode to work better. I don’t remember exactly how they came to their conclusions but a search would reveal the answer. Try DC Rainmaker, GP Lama, Zwift Insider etc.

1 Like

I tried to put this to the test with my own Neo 2 and Assioma Duo pedals for power comparison while holding a steady 200W in erg and changing up through the gears each minute.

The results showed no obvious trend in power figures regardless of gear choice. Here is the flywheel speed profile as I warmed up, stopped to calibrate the pedals and then performed the 200W steady effort through the gears.

Here is the power data that matches with the session above. Note that the pedals show power consistently above the Neo to the tune of about 7-9% on average. Unfortunately my Neo 2 is one of the lemons that under reports power. It is my third Neo and the only one with such a shocking error, but that has nothing to do with the test result, just my little rant. :slight_smile:

Oh, and I tried to maintain steady cadence as I changed through the gears.

Of course, there is nothing to say that the behaviour of my Neo 2 should be mirrored in other trainer models.


Some great data here; so the burning question is, did you notice any significant change in effort required to sustain the power output using different gears? Do you have heart rate data for the same session?
It would be interesting to see if your HR went up when using the easier gears.
I guess it’s possible that based on Fez’s posts that with my 50x19 I’m seeing some flywheel benefit whereas maybe the 50x28 is more neutral.

Here is heart rate vs cadence. I don’t think it is possible to spot any pattern in heart rate with gearing. It goes up and down pretty much at random. You might expect some upward drift after a while, but nothing evident in this short Z2 effort.

By the way, not that it changes the results, but I think target power was only 180W rather than the 200W that I stated earlier. At least that looks to be the case on closer (less lazy) examination. I performed the test on 7th August, so the memory got it wrong.

1 Like

naturally spinning at 100rpm seems really fast to me! i think my natural is more like 75rpm.

i definitely see my heart rate go up as my cadence increases, even if resistance is flat. spinning faster seems necessary for consistently pushing more watts, though, so i try anyway!

I usually start around 85 when I’m cold but on the road average between 95 and 100 for a five hour ride. I think it’s just down to physiology. Some push, some spin. It’s actually the opposite for me with heart rate. Obviously it gets high as I’m working hard but on the trainer, if I drop below my comfortable cadence threshold to the point where I’m having to ‘push’ to achieve the same wattage, my HR goes up and I start to burn out.
OK, so all in all it looks like there’s quite a good chance I was either having a really bad day. Next time I’m stuck indoors I’ll try the same test again on a granny gear just to see how it flies.
Thanks all.