choddo

Not sure I ever get the chance to ease off that much in a race. Do you think zwift do it to reduce the impact of comms glitches?

PeteHski

Yes, I think so. I find that I can ease back quite a lot when riding in the pack or on descents, although I find that quite realistic. Obviously can't do that when climbing or going full gas just to hold on or bridge a gap. But if you do soft pedal for a few strokes you don't lose as much ground as you would in real life. I now see this effect quite clearly when comparing directly with my Wahoo wheel speed.

Jughed

Zwift high cadence on the flats vs low cadence climbing similar power levels.


Did 100k flat ride at a normal cadence and a comfortable power level, 190w+\-. Zero fatigue, plenty of reserve power, easily in zone 2- fun ride.


Just did Mt Ventoux at the same power level with the trainer resistance set at 90% to allow for a slightly higher cadence-75 rpm average. I hour less time in the saddle, fully gassed at the end, never in zone 2, elevated heart rate and breathing. This ride destroyed me.

Climbing Vs flat- to rule the difference out. I also did Alpe de zwift with the trainer set at 75% allowing for normal cadence levels, and I averaged 50watts more and was never as gassed out.

not sure what to make of that.

choddo

Maybe just rested more for the first one but that sounds like a big difference.

What was “normal” cadence? 75 is pretty low. Maybe calling on less developed / trained muscle fibres?

Jughed

85-90 is “normal” for me.


Equal rest +\- for all three rides.

On the Alpe, at normal cadence, I was able to start the climb in Z3, continue to add power, was doing FTP+ intervals on every other segment, and finished with a full on sprint at the top.

On Ventoux, at lower cadence, I couldn’t maintain low Z3 levels, forget about getting into z4, and at the top I was dead gassed out.

Hate to say it, but I have do both of them again while using my power meter pedals as well. Could be a trainer issue at lower cadence… my butt meter didn’t match the trainer readout at all.

PeteHski

A good way to rule out the effect of climbing or any Zwift inflation of average Wattage on flatter rides may be to use ERG mode at the same power at low vs high cadence. I think ERG mode may provide a more “honest” report of your average Wattage in Zwift, particularly on flatter terrain.

Comparing average power reported via Zwift in sim mode vs average power reported in my Wahoo app for the same ride was an eye-opener for me.

cyclezen

A lot of the discussion has been very theoretical... cadence v torque. But reality is way different. There are limits to both and the curve to those points can vary dramatically, depending on the motor.
Heart and Lungs going 'longer' is a very personal assessment. Depending on where one is relative to his 'motor's design (training) either power can be more optimized, or cadence (aerobic efficiency).
Comparison of a rider who bounces in their saddle at 90 rpm vs rider who can spin 120 easily but can;t with a 92"+ gear (scuze my oldschule gear inches)..
Real world is way different than a comparison of two curves with 'infinite' combinations of torque and cadence.
Many riders don't have the muscle structure to put out 1K watts, at any time. Many have such low efficiency that riding for 100 rpm for more than a few seconds has them bouncing uncontrollably on their saddles.
A wonderful part of cycling is what happens when all these variables combine. So a world class track sprinter can put out amazing torque at 130 rpm for an amazing time to put out 2000+ watts - ... enough to do 120-150 meters at that level. But may not fare as well in a 40K time trial.
Cadence (muscular efficiency) is a very important part of the equation, but certainly not the fully deciding part... same said for torque...
... so where are we... somehow one needs to work/train at both. 'Natural' is to fall into the one you find more suited for 'you' - hard (and very productive) is to work on what comes with more difficulty.
depending on the situation 'going longer' (as with using aerobic fitness/cadence) may not suit the Question asked of you. Spinning up a difficult 'Roller' may get you up there, ready to drive down the other side. BUT, if you're in a group where others are 'powering' up the roller and 25 yds ahead of you at the top - being 'shelled' off the back may mean a solo ride, behind...
If you're on your own, it just means 'that's my ride'...
... it all dependz...
Of course, if one never really taxes themselves in various situations - one never really knows where the strengths and weaknesses lie.
cadence - is easy to monitor and you get direct feedback when your riding is focused on that. And pedaling efficiency improvement has a broad affect on overall improvement.
torque, much harder to isolate and monitor - yes 'power' measurement, but also harder to measure relative to the other variables.
Ride On
Yuri

choddo

Wonder what would happen at 40% trainer difficulty where you could run a higher cadence

PeteHski

I agree that it is useful to “train” both higher and lower cadence for different benefits and over time a trained cyclist’s preferred natural cadence will generally increase. I find a good way to work on increasing and maintaining my natural cadence is to ride +5-10 rpm higher than my comfort zone for a period of time. Just high enough to require a conscious effort to maintain. For low cadence training I simply do a lot of sustained climbing with gear limited cadence.

Given that the OP is looking to optimise power in a steady TT it is really about riding at a relatively comfortable, natural cadence with a sustainable HR.

RChung

Hmmm. I don't think the cadence vs. torque discussion is particularly theoretical. I think what it shows is pretty damn practical: that there are lots of different combinations of cadence and torque that riders use, so to focus on cadence alone is short-sighted. The cadence vs. torque stuff shows that you can (and for some, should) work on both, not just one or the other. That's liberating, not constricting: you don't have to be a metronome to train well.

wheelreason

Yeah, we're not electric motors, (though we do have 2 legs of power)...

cweb99

What are watts used for? I just use cadence and try to pedal as fast as I can with my preference cadence at 80-85

PeteHski

Watts are a measure of your power output, which determines how fast you will go. Cadence alone is only half of the power equation. The other half is how much force you are applying to the pedals.

So for example, if you pedal at 85 rpm in a low gear then you will produce less power and be slower than if you pedal at the same 85 rpm in a higher gear in the same conditions.

chaadster

Watts are used to understand how hard you’re actually working. You can turn the pedals fast or slow, but that only tells you how fast you’re turning the pedals.

Using watts, you can know your limits, and decide where you want to exert your efforts within those limits. Cadence is really just an adjunct to watts in terms of performance.

wheelreason

Folks are power happy these days. I don't care how many watts I'm putting out, I care how fast I can make my bike go, sure there is a correlation, but like I said, we are not electric motors. Right around July most race seasons, I could spin the 53/15 on a flat road and stay on top of it throughout a training ride, Don't know how many watts that was, but I know I never owned the 14 like that on a consistent basis. Saw Alex Steida (with his skinny legs) spin a 13 on a crit once, and knew instantly I would never do that...

choddo

It adds a lot to training. Especially for those of us who are never going to race (except the odd friendly TT maybe) and want some kind of objective yardstick. Speed isn’t always a useful measure of progress in changing weather and traffic conditions.

asgelle

I'm still trying to wrap my head around this*. There are two things that control how fast a bike goes. The power produced by the rider and the forces resisting motion. If you're interested in going faster you can increase the former, decrease the latter or both. I don't think you really believe the only way for you to make yourself faster is reducing the resistance.

*It has the flavor of keep the government's hands off my Medicare.

choddo

I think he’s saying he cares about the end result and focusses on that (sometimes aero position, technique or racing tactics beats watts when it comes to increasing average speed so you can miss the bigger picture if you hyperfocus on power output. Also, see examples of Froome crashing due to too much Garmin)

Trakhak

The bolded line is tangential to your point, obviously, but: what examples? Links?

The only info I found concerning Froome crashing referred to his catastrophic crash that all but ended his career:

"According to Poels and Brailsford, a strong gust of wind caught Froome's wheel and caused the Kenyan-born British rider to lose control. [Froome had one hand off the handlebar, blowing his nose.] Froome was traveling at nearly 55kph on a straight section of road lined by houses when he struck a low wall and crashed heavily on his right side."

wheelreason

It's simple, if I can make my bike go faster, I'm obviously putting out more power, so I train (or rather trained) to go faster, and the power takes care of itself, I don't care about the number. And while I wasn't referring to efficiency, that takes care of itself too.

PeteHski

Everyone who uses a power meter is also training to go faster. Direct power measurement just makes it far easier to track real time gains/losses. Bike speed is a pretty crude proxy for power unless you are training in a Velodrome.

wheelreason

ok.

choddo

Sorry it was a bit tongue in cheek and I should have made that more obvious. People used to refer to it from the frequency of his crashes and the fact he was known to ride to power (very successfully) most of the time so was he too busy staring at his power numbers, but don’t think there was ever a real case of that contributing to him having a spill.

Sierra_rider

For a correlation between power and cadence, my cadence increases as my power increases. My "noodling along" cadence is around 90rpm and will go all the way past 100rpm for a max effort. Low rpm efforts with lots of pedal force, just fatigue me a lot more than increasing the revs and dropping the force(for an equal power reading.)

To add to that, the power meter is also the means to improvement and not just a measure of that improvement. By utilizing power zones nowadays, I'm much fitter/faster/stronger than when I was just simply riding lots and hard.

rclouviere

exactly. It seems I’m now more efficient and, as a result, faster using a lower cadence. I don’t seem to get as winded as with higher cadence. Not sure if this makes since.