?? Cadence versus torque and power, any data?

[rareposter]

Agree with everything Nearholmer says above - this is one of those aspects of cycling which, for most people "just happens". That is, they find, by trial and error, a combination which works for them, the terrain they're riding, their fitness level, the type of bike and so on.

The other option is to massively overthink it...

[853]

I have experimented much over the decades, and found a high cadence - low torque technique gets me up hills at the fastest speeds.

I'm at the skinny end of the scale, around 9st 7lbs in weight (it varies slightly), with skinny legs to match. I don't have a great amount of muscle volume, so I will never be able to produce a huge amount of torque. As a result I always ride in the saddle, and if I want to 'go for it' I can ride at around 120rpm for a couple of minutes. I don't get any leg fatigue from doing this either, like I did trying to 'push' bigger gears.

My feeling is that your optimum cadence and torque depends on a lot of things, but one factor is the amount of leg muscle you have and the fast twitch/slow twitch compositions.

[Nearholmer]

^^^

Completely agree.

I’m what might be termed ‘mid legged’ in degree of muscle; the chap I mentioned earlier who rides very high cadence is distinctly spidery; and, a younger pal has absolutely huge thighs, like a weight-lifter, and he is a low-cadence man.

[Tigerbiten]

I've a nice long hill I can pedal down at 30 mph.
If I'm turning a 100" gear at 100 rpm then I get to the bottom of the hill with an elevated heart/breathing rate because I'm well above my optimal cadence range.
If I'm turning a 130" gear at only 77 rpm then I get to the bottom with the same heart/breathing rate I went over the top with because I'm well within my optimal cadence range.
I've never been able to ride at a high cadence, my legs/body are not built that way, so my optimal cadence is in the range 70-80 rpm.
If I'm overheating on a hill climb then I'll drop my power output by both dropping a gear or two and my cadence to around 60 rpm. The one thing I won't alter is the pressure I put on the pedals.
When I had my recumbent trike build for me I went for the maximum gear range possible.
I've ended up with an 18x range.
The advantage of the mega range is I rarely run out of gears at either end, so I can keep the same pedal pressure and be within my optimal cadence range over the full range of speed I hit around home.

[Carlton green]

It’d be interesting to hear what those who ride single speed freewheels and fixed gear think and find.

Talk of just gearing down and not worrying about things is pragmatic enough, well pragmatic enough when you have loads of gears but my favourite bikes are simple ones with a relatively narrow gear range. Informed technique helps you get the best out of what you’re using and what you have. Data helps inform technique.

[rareposter]

It’d be interesting to hear what those who ride single speed freewheels and fixed gear think and find.

I've ridden a SS road bike for 20 years - it's had various build iterations, components etc but the same riding position.
I've ridden and raced track quite extensively, indoors and out.

And I can honestly say that I've never really given it much thought, certainly not enough to go delving through graphs.

On indoor velodromes, there's a gear restriction of 88" in training sessions - you can go higher for races but t's not really the gear that makes a difference (especially when everyone is on broadly the same ratio), it's tactics and fitness and most bunch races will go through periods of intense action and periods of relative calm. I've also seen plenty of Youth / Junior riders on restricted gears beat adults on higher gears so either they're just much more heavily weighted towards the cadence end of the equation while the adults are going for more torque - or it's better tactics!

On the SS, it came with 48:16 when I bought it (79" - fairly high) and I rode that for years before dropping it to 48:17 (74") which I ride now. High enough for decent speed on the flats, low enough to get turning going away from traffic lights etc. For me - other riders may of course have other opinions...

But honestly, the torque / cadence thing is irrelevant. Find a gear that works for you and "feels right". I know that SS ratio is about right for me because it sits roughly in the middle of the gears I'm usually in on my geared road bike on the flat so it's a sensible starting point. Putting a 60" or 110" gear on it would have been insane but putting a 74" on there is a logical starting point based on my riding experience on geared bikes. It really doesn't need any more thought or maths beyond that.

[Nearholmer]

I sometimes cycle with my son (cumbersome 12sp bike, but never changes it out of top gear of c80”), and/or my nephew (single speed) and they both operate on what might be called “the infinitely variable cadence method”, stomping it out up hills, whirling round downhill, and both spend half the time out of the saddle. They’ve both got super-strong legs (ex-university rower, and keen footballer respectively).

I do beat them up long hills by use of gears and the cunning of age, but everywhere else they’re looking back over their shoulders to see where I’ve got to.

[Tigerbiten]

If I'm looking a new bikes gears, I start with the range 40"-80" as that is around the range of my most commonly used gears.
Where is it on the cassette and what are the steps like between the gears in this range.
Then I'll look at the bias of the gears, how many above 80" vs how many below 40".
I like very close to a 1:2 ratio.
I know a road bike with close to a 1:1 ratio won't have enough low gears.
Not tried a MTB with a 1:3 ratio but also don't/cannot ride where that ratio is useful.

[axel_knutt]

The graph I like is an efficiency one of effort vs cadence, I saw it once and cannot find it again.

Do you mean this one?

After I wrote that I discovered Coast & Welch, which shows plots like the one I described, so I think I'm on the right track. Here are plots of VO2 and heart rate vs cadence which both go though a minimum where waste energy is at a minimum and cadence is optimised for maximum efficiency:

.
And here optimum cadence increases linearly as a function of power output:

.
The two almost identical curves are the ones derived from VO2 and HR, and the third plot that levels off as power increases was from a separate study by Seabury, using untrained subjects unused to higher powers.

If you're riding up hill you need lower gears because you riding more slowly, but then you need lower gears still because you're also using a higher power, so the 'double whammy' means you quickly run out of gear range to achieve your optimum cadence. Sitting down and spinning should be a better way to climb than honking, just as long as you have the gear range to do it.

[Nearholmer]

^^^

Very interesting, and IMO of more practical use than the plots I posted.

[axel_knutt]

Are you suggesting that "ability to climb" is limited by the power or by the torque delivered by the rider?

The limits are
a) being able to exert enough torque to overcome gravity
b) being able to produce enough power to maintain a speed at which you can balance the bike.

Either of these may stop you.

For any common (effectively identical) gearing arrangement the torque generated at the crankshaft and back wheel appears to increase as the cadence drops.

No, for any given gear, the torque you can exert will be limited by the force you can apply to the pedal. That's not going to increase if you slow down (unless you were previously pedalling very fast). On the other hand, torque at the wheel can be increased by a lower gear, which will increase your cadence and/or reduce you speed. Changing gear won't change your power output, changing speed does.

[axel_knutt]

Possibly the best way to understand this is with your legs and lungs, by finding a hill of suitable gradient and length, and going up it using different gears/cadences.

Agree with everything Nearholmer says above - this is one of those aspects of cycling which, for most people "just happens". That is, they find, by trial and error, a combination which works for them, the terrain they're riding, their fitness level, the type of bike and so on.

The other option is to massively overthink it...

To find your optimum cadence (which will change every time your power output changes remember) just adjust your gears until your heart rate is a minimum. Having tried this I found that the gear I ended up in was the same one I was finding automatically by what just feels right, so I stopped bothering.

[Tigerbiten]

They are similar to the graphs I've seen.

I like to ride with a light pressure on the pedals and at a comfortable cadence that I can keep up for hours.
On my bent trike, I've trained myself to ride like that.
No idea if it's my optimal cadence but it feels right.

[cycle tramp]

The other thing which we have to touch on is the longevity of our joints, and whether its believed that an inappropriate crank length and a cadence which is too low or too much force will damage them, both long term and short term...

...if we accept that the length of our foot and leg limits the crank length we use, then it may be a natural assumption that the taller person will have a lower rpm to reach 10, 15 or 25 mph than a shorter person - similar to walking - where a taller person may take less steps to cover the same amount of distance than a shorter person...

..in which case any studies may have to give the subjects leg length and foot side to produce any meaningful data..

[Carlton green]

The other thing which we have to touch on is the longevity of our joints, and whether its believed that an inappropriate crank length and a cadence which is too low or too much force will damage them, both long term and short term...

...if we accept that the length of our foot and leg limits the crank length we use, then it may be a natural assumption that the taller person will have a lower rpm to reach 10, 15 or 25 mph than a shorter person - similar to walking - where a taller person may take less steps to cover the same amount of distance than a shorter person...

..in which case any studies may have to give the subjects leg length and foot side to produce any meaningful data..

Thanks for raising this. I’m interested in the relationship between torque and cadence; I’d ask people to be mindful of pushing their joints too hard - ‘just because you can do something doesn’t mean that you should’ applies to many things.

I read here of folk using fixed gears and quite high ones at that, they must generate a lot of low cadence torque to get them started and, assuming their cadence drops, to get them up inclines (my own cadence drops when hill climbing, until I change down a gear or two).

At the gym some folk use leg presses. What you can shift at slow speed and limited reps is much higher (load) than what you can shift at higher speed and greater reps; an observation with doubtless overlaps to cycling. I wonder if there is any helpful data on leg press loading and exercises.