Bacciagalupe

In this context, "efficiency" (or "gross efficiency," to be precise) refers to the ratio of oxygen consumption to power output.

Long story short: You put out more power per minute with a slower cadence, but your aerobic system needs to work significantly harder to keep it up. Your "force effectiveness" (also called "mechanical effectiveness") is high, but your gross efficiency is lower.

https://link.springer.com/article/10....421-011-1914-3


Correct.

Correct. (Though you also have more points when you are supplying force to the drivetrain.)

However, you're leaving the aerobic system out of the equation. When you're mashing, you are predominantly using your leg's muscles, which can be powerful but can't keep it up for long, and makes the rest of your body work harder. When you spin, you are shifting the effort to your aerobic system. As long as you don't go anaerobic, and can maintain a good calorie/carb intake, you can literally cycle all day long.


It is, but afaik that isn't because of the pedal stroke. It's because the chain is always in a straight line, and there is far less friction than if you are using a rear derailleur.

RollCNY

No disrespect, but the 5th sentence of the summary that you linked says that, for all 3 subjects, gross efficiency and force effectiveness decreases with increased cadence. I am sure you believe that higher cadence is more efficient, it just looks like your linked study shows the opposite.

Also, I listed the same reasons you did for why a single speed is more efficient, and didn't say it had anything to do with cadence. I only brought it up because I often see posts saying geared bikes are more efficient than single speeds. It was an example of people using the word efficient, IMO, incorrectly.

Could someone with science weigh in? Like Drew?

wphamilton

Yet there seems to be no correlation when it comes to anaerobic efforts, between cadence and maximal accumulated oxygen deficit. Or with lactate levels. https://link.springer.com/article/10....421-011-2240-5

My questions in the aerobic case are: How much power does the change in gross efficiency represent, and how much does the difference vary between individuals? My purely personal reason to wonder is that when riding at tempo I can detect no difference in my heart rate or respiration rate when riding at a higher or low cadence. Unfortunately without power equipment I can draw no firm conclusion from that, but who wants to waste 20 watts for example at a less efficient cadence?

Carbonfiberboy 

How'd we get off the rails and over in this pasture again? Efficiency, as correctly defined by BG above, goes down as cadence goes up. IIRC from reading many studies of the matter, GE peaks around a 55 cadence. So if you were well-trained at using this cadence, you'd be fastest up say one 15 minute hill at this cadence. The problem is that low cadence burns glycogen more quickly, so we run out more quickly. Hence long periods of high power output demand that we use the normally advocated 85-105 cadence on the flat. Due to the lower climbing speeds and thus momentum of most recreational riders, a somewhat lower cadence of 70-85 is usually faster on long climbs. This seems to be due to a greater ease of varied muscle recruitment at lower speeds and cadence.

Be that as it may, IME and in the studies mentioned in this thread, climbing ability is improved by low cadence workouts. SS is not more efficient as defined. In fact, it's the least efficient, since the rider will very seldom be in either the most desirable or efficient cadence. The minuscule change in drive train friction losses is unnoticeable beside the much greater physiological losses.

RollCNY

Thank you. That is all I asked. I have no question about sustainability or impact on energy stores, and I don't think anyone here disagrees about that.

I didn't mean to diverge into the SS conversation, which has nothing to do with the OP. However, your statement of an SS being least efficient is incorrect, even by your own logic, If 55 rpm is maximum GE, then it is maximum GE on any bike. At any given cadence, for a given rider, an SS is more efficient than the same cadence on a geared bike, because it doesn't have the minuscule losses. Now I am not saying that is the optimal power output, or that it makes for a desirable cadence, and perhaps "can achieve the highest efficiency" would be a better way of saying what I mean.

I will end my thread diversion, and apologize OP. I meant no derail, and thought it went in conjunction (except of course for the SS crap).

cyclezen

this is all ishtar

mash makes juice

SethAZ 

I've been thinking about cadence lately. I haven't been road cycling all that long, and learn a great deal by reading, that helps me understand what I'm doing while I ride, if I pay attention and observe. I read this thread with interest, and put it into context with what I've read in other sources about high cadence riding, why it's done, what it does for a rider, etc.

It's likely you guys are all thin with optimum cycling body types, and maybe this belongs in the Clydesdale forum, who knows. I'm a big guy at 6'3" and around 270 lbs (and falling, albeit slowly now). I used to be 380lbs. I dropped from wearing size 53/54 pants to currently wearing size 40 pants. What does this mean? It means I've got very large legs compared to the "ideal" cyclist.

So how does all this cadence talk change for people with large legs? It takes a certain amount of energy just to spin one's own leg mass. With zero resistance, there's still going to be a limit to how fast a person could spin just because accelerating one's legs up and down as they spin on a bike takes effort. The larger the legs, the more effort.

A few months ago when I configured my bike's computer to display cadence, I noticed I was riding a lot in the mid to upper 70s. After reading a lot about higher cadence, I've pushed my cadence up a bit and found some benefit, but I still max cruise at maybe 85 rpm. 90rpm definitely is red line for me. There's just too much leg to contemplate spinning any faster than that.

So I'm definitely more on the masher side of things than the spinner side. Even climbing, last weekend, when we did a 7300 foot climb up Mt. Lemmon in Tucson, Arizona, in my lowest gear I was mashing along at cadences generally in the 50s, but on the steeper grades it could get into the 40s. I'm still changing my gear configuration, with a compact crank on order that will arrive in a couple days from PBK. That will boost my RPMs during climbs somewhat, and I'm interested in seeing how that impacts my climbing endurance.

Anyhow, I'm starting to think that with my body type, I'm destined always to ride at a lower cadence than you thin guys, and instead of reading what you all do and trying to do it myself, I might be better served trying to optimize my bike and riding style for the type of body I have. I'm thinking of moving from a 175mm crank to a 180mm, for instance, to complement my lower-cadence mashing style and perhaps improve my endurance by reducing the effort those fast-twitch muscles have to put out for each rotation.

Anyhow, mashing has certainly made me stronger. But it has had to, because mashing is what I'm stuck with.

bonz50

with regard to the bolded portion..... are you suggesting that you will build additional capillary in your muscles?? i'm not quite understanding this

rumrunn6

be kind to your knees, or maybe you want a torn knee meniscus

https://www.google.com/imgres?sa=X&bi...27&tx=84&ty=52

Carbonfiberboy 

You bring up interesting points. Allow me to reason by analogy. Auto racing engines have long pursued ever higher RPM's in the quest for horsepower. Since power = force X speed, the faster the engine spins, the more horsepower. With reciprocating engines there are obvious limits imposed by the strength of the parts being accelerated. With turbines, there are again limits imposed by the strength of parts due to what is commonly called centrifugal force. Dealing with reciprocating engines, there are frictional losses in the bearings, gears, and in the pistons sliding on the cylinder walls. However, the losses due to rotational speed are limited to air friction in the crankcase and don't involve the acceleration of the rods.

So, back to cycling. This fellow on the podium:

has pretty good-sized legs, yet he can spin them very fast indeed, being a champion track racer.

All that said, as the previous discussion indicates, efficiency does go down for human cyclists as cadence goes up, I think due to losses involved in the rapid contraction of muscles, nothing to do with accelerating leg mass. And it may very well be that cyclists with higher leg mass lose efficiency more rapidly with increasing cadence than cyclists with lower leg mass. That's an interesting supposition and I wonder if there's any evidence for it.

In any case, an 85 cadence is totally reasonable. I know a very strong long distance racer whose self-selected cadence is closer to 60. He's very unusual, though he can also spin very fast. It is advantageous to be able to ride at cadences inside a wide power band, whether they are more efficient or not. I suspect that with a bit of concentrated training, you could easily ride at cadences over 100 for short periods.

My advice, though it is not asked for and thus is dangerous to give, is to try holding a lower gear for a few minutes at a time. On the flat, spin up to where you start bouncing in the saddle and just stay there for 2-3 minutes. You'll be going slower than you would in your self-selected gear and cadence. Repeat a few times during a ride. Relax your legs and concentrate on cycling using the uppers on your shoes, with a cushion of air beneath your foot if possible. Concentrate on your feet. I think you'll see benefit from doing this in a couple of weeks, even if you don't change your normal self-selected cadence.

Carbonfiberboy 

Much of this depends on your pedaling technique. I understand that you were climbing out of the saddle in a very low gear. I never stand in a gear that low, i.e. in a gear in which I have no momentum to keep the bike moving. The next time you climb a hill like that, sit it. Hold your body still and just rotate the pedals, pushing and pulling on the pedals all the way around the circle. Don't allow the bike to decelerate and accelerate. That's how you build strength as is being discussed in this thread. Just dropping your weight onto the pedals costs you energy and doesn't build the same kind of muscular, cycling-specific strength.

SethAZ 

True. I'm not 100% clear on the physics of this, but, just to consider the ill-fated and oft-joked about "Shake Weight", there's work involved in reciprocating a mass up and down. The more weight, the more work involved. The rider pictured above is so massively muscled that it could also be argued that his muscle mass includes enough muscle to be able to accelerate his own muscle mass up and down that fast. Well, that much is obvious. I guess what's not obvious is whether massive-legged "normal" folks, ie: people not as athletically specialized and supremely developed as that guy, are better served by spinning faster, or by mashing more. I honestly don't know.

And, to be honest, I did take my 75 rpm and convert it to 85 rpm high cruising speed by thinking about it and working accordingly. I can't say for sure that just because I cannot now spin at 95 rpm for longer than a few seconds that I couldn't develop the ability. I just don't know.
That's very interesting. I've been thinking of converting some of my mundane 25-mile typical rides into more valuable rides including some intervals and whatnot. I will have to experiment with this and see whether or not this 85rpm max cruise really is max for my body type, or just the max so far based on how I've trained and ridden.
Thanks for that advice. I'm still relatively new to cycling, so what I've done so far is just what I've figured out thus far, not what there is to know or do. I'll do as suggested and see, over a few weeks' time, how it affects my riding.

rousseau

Just trying to keep up here. Surely you mean high gear? He said he was mashing up a hill at a very low cadence, indicating that he was in a higher gear. Or am I missing something?

Either way, doesn't mashing up hills in higher gears somewhat mimic the squat machine in a gym?

Drew Eckhardt 

It usually doesn't. For all but the shortest durations your limits come from lactic acid accumulation with your lactate threshold substantially (I get there cycling with a heart rate around 162-164) lower than VO2max (192) and your heart and lungs have plenty of headroom to deliver more oxygen.

OTOH, the higher cadence can allow higher maximum power because you recruit more muscle fibers

https://www.ismj.com/pages/311417173/...ng-cycling.asp

and lets you do that longer because you accumulate less fatigue.

https://www.ncbi.nlm.nih.gov/pubmed/8970143

Empirically you'll do best (feel better, fatigue less, go faster) if you increase cadence with power output. Riding intervals approaching my lacate threshold 85-95 RPM average feels good, at a five minute pace 105 RPM works better, and sprinting I like to shift about 120 RPM although 60 RPM is great at a recovery pace.

The specifics vary between different individuals with varying balances of fast and slow twitch muscles a plausible hypothesis.

Carbonfiberboy 

Squatchy should be the one to say.

1) I use a triple. IME, if I'm standing on a 19% grade and the bike stops when the pedal bottoms, I'm in my granny ring. So for a compact, small ring, large cog. If I were in the middle ring, the bike would have enough speed to keep moving. At 19%, I'd only climb out of the saddle in the middle ring at a sprint pace, so not more an a one minute hill, but I'm just an old duffer. If it were long, I'd sit it in my granny.

2) Somewhat. Barbell squats primarily strengthen the pushing muscles. If you sit a really steep hill, you'll quickly see you need a lot of other muscles to get involved in keeping the bike moving at a steady pace, which I think is what we're talking about in this thread. Pretty hard to stimulate all of them in the gym. I can sit a climb OK down to about a 30 cadence, keeping a steady pace. Fortunately, I've never seen a climb so steep that I couldn't sit it at 30 cadence in my granny. That's probably about 2 mph.

squatchy

Hi Bonzo.

Yes that's what I am implying. Adaptation can occure at substantial levelsa for as many as 10 years. Tha's one reason why you normally don't see many youngsters do well in indurance sports. I have read ( I think in Charmichaels book, maybe Kogen) that as we train our bodies create much more capilarie beds so as to be able to deliver more oxygen to your muscles. Not only that but as we all know our veins and arteries get much larger to accomodate this as well. The reserch suggest that when we begin to train this may go on for 10 years before we have developed as much as we are able. Lastly, we also create more mitochondria as well as the current ones we have learn to produce better results from use.

In Tyler Hamiltons book I remember a statement he said that was something I also had known for a while. If you look at a riders legs you can tell how well they are developed to a good degree by looking to see how large and to what extent his arteries and veins are crawling all over his legs on the outside of the muscle and under the skin. What I am saying is that on long time invested riders thier blood vessels are huge and scrawl all over thier legs. Compare that to someone who does nothing and you can't even see any vessels. I work with my hands and my vessels on my arms are bigger that a pencil where as most people you can't even see any except for on the back of thier hands.

I have been told this is why the younger kids are not so impressive and that this is why guys come into thier prime in the late twenties rather than in the early twenties in endurance events. Lastly once this is built up it takes forever for it to dissapear and that is why long time rides loose thier fitness much slower than a guy like myself who has only ridden for a couple of years.

squatchy

Hi CFB

I was actually in my granny gear and sitting. I always sit to climb if I'm"working out". It was so hard for me I could barely keep the bike moving. Any slower at all and I would have fallen over. It would seem to me that mimicks one legged presses in a squat machine pretty closely.

I sit on lots of pitches where most peps stand. I weigh #250 or more and it's my way of building leg strength. Of course I will stand if I can't get up sitting, or to keep up with my group (although at my weight most often I get dropped on longer climbs for a bit). I find that once I have spent my juice climbing sitting in my saddle, I really don't have far to go once I stand before I am spent because I have depleted both my oxygen and gasoline.

I doubt anyone realized how much energy we clydes have to expend to do some of what we do. My Garmin usually shows me burning 2 times the amount that my GF spends riding the same route. I have seen where I need to generate 450 watts to do what she gets done at less than half that.

Carbonfiberboy 

Thank you for the clarification. Yes, I understand about the weight completely. I've been riding a tandem with my wife, who puts out less than half my watts. We weigh about 340 all-up.

Anyway, next time you're on a steep hill, do as I described in that quoted post. Don't push down particularly. Instead, just rotate the pedals smoothly. Push forward at the top, hard, push down a little, pull back hard at the bottom, and pull up some on the backstroke. You'll find this very hard to do, but do it anyway. A few weeks of doing this and you'll notice positive results.

Another painful thing you can do is: on a slight grade, maybe 1%-2%, unclip one foot and pedal one-legged, trying really hard to keep a taut chain. Try to do that with each leg for at least 2 minutes. Ouch. But it works.

squatchy

Every spring I do a bit of one legged drills as well as a fewevery few months just to refresh my memory.

As a side bar, I have found, For me any way, that I used to ride with my saddle just a bit too high, even though I didn't rock back and forth. I have since learned that if I lower it just a bit I can really feel a difference in how easy (or not easy ) it is to get over the top of my stroke. I believe if I can get over the top a little more naturally then it surely must add to the overall fit/performance when riding in general. This is now how I fine tune my saddle height for myself and significant other FWIW

squatchy

I failed to say that it is with one leged drills that I could find the sweet spot for saddle height if that didn't seem obvious in my above post