Pedaling in Circles
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i think i know who the quack is here... remember in physics class that thing about for work to be accomplished the force or at least a portion of the applied force must be applied in the direction of the motion?swampy1970 said:
if at 12 o'clock you apply force straight down you are applying force perpendicular to motion... i.e. you are accomplishing NO work.
If we're in a pedantic mood.....doctorSpoc said:i think i know who the quack is here... remember in physics class that thing about for work to be accomplished the force or at least a portion of the applied force must be applied in the direction of the motion?
if at 12 o'clock you apply force straight down you are applying force perpendicular to motion... i.e. you are accomplishing NO work.
Work is done if you push on the pedals when the crank is vertical - you actually push backwards. If you apply force to the pedal when it's in a position where there can be no forward or backwards motion through application of force on the pedals, work is still done, but it causes ones backside to be lifted off the seat - contrary to popular belief, this isn't when the crank is vertical when viewed from the side, it's acutally just past it and is dependant on saddle position, leg length etc etc etc....
But, nitpicking aside, this is why I put the big "?" in the reply....
nitpickicking... gime a break.. please! did you read my post?swampy1970 said:
"if at 12 o'clock you apply force straight down you are applying force perpendicular to motion... i.e. you are accomplishing NO work."
read carefully... that's not describing the same situation that you are... the situation i describe in my post (and n crowley to) results in no motion since you are appyling force parrallel to the crank arms.. well no motion unless you are strong enough the crush the crank arm on itself or you are lifting youself off the seat as you describe, but you are doing no work in propelling the cranks and bike forward... i think we all are smart enought to know that we are talking about work that propels the bike forward... that's a good assumption right?
you are describing a situation where force isn't applied straight down.. you may think you are, it may feel like you are but you aren't... remember physics class again, you are wrong that can be said with 100% certainty.
[edit]
so you state why you put the "?" in you post... why did you put the "quack" in your post?
I stopped assuming years ago...doctorSpoc said:
Why did I put a ? in the post - see the highlighted contradictions on the last page.
I put quack.... because I felt like it and because it made as much sense as Norms post.
"you are describing a situation where force isn't applied straight down.. you may think you are, it may feel like you are but you aren't... remember physics class again, you are wrong that can be said with 100% certainty."
Say what again? Where did I imply that you push straight down all the way through the first 180 degrees of the pedal stroke? I know that even if you "mash" like Norm described you're not applying a purely vertical force and during more than a decade for time trailing and road racing I've never thought that I was just pushing straight down. Besides, given all the recently developed muscles in my poor aching legs from the use of Powercranks, I have a way better idea of what's going on now than back when I was timetrialing for a couple of hours at 27mph on my trusty 531 timetrial bike.
tired of arguing semantics..swampy1970 said:
the point is that if you want to impart the largest force vector to the pedal, you want to be pushing at as close as possible to tangent to chainring.. i think this is the point that n crowley was making.. if you are mashing.. higgly, wiggly you are potentially appling lots of force trying to compress and stretch your crank arms and keep yourself in your saddle instead of it actually going to moving the bike forward... not arguing for pedaling in circles... you can mash.. but how you mash, how you apply the force, the angle actually matters.
doctorSpoc said:
The point I am trying to make is that if at mod to high cadence you attempt to apply max vertical power to the pedal when it is at 12 o'c, by the time this power reaches the pedal, the pedal will have moved on to a position where this power can be effective, but of course it will only result in a small percentage of tangential power. Pedaling is all about brain signals, muscle reaction and results and these are not simultaneous, that is why the pedal will have moved on. Proof of this can be found in the emergency stop when driving a car.
what you are talking about is why the cyclist cannot "think" about pedaling. Pedaling is an ingrained reflex action that will occur whether we think about it or not. We are capable of modifying it through conscious action but such modifications are coarse and not well controlled for the reasons you specify and no one can think about what each leg is doing 180 times a minute for 5 hours or so.n crowley said:
When one is learning to pedal one learns what "works" and what doesn't based upon how fast they find themselves going at what effort. As this "optimum" coordination gets fine tuned it then continues to be reinforce and soon is totally ingrained. Unfortunately, that pattern is learned when we are not attached to the pedals so we learn to keep some back pressure on the pedals on the upstroke so we can maintain contact with the pedal the entire circle. Hence, everyone's ingrained pattern does not resemble "pedaling in circles"
Changing how one pedals a bike after the pattern is established and ingrained is a very difficult proposition. Buying clipless pedals is not enough.
When I am doing my L6/L7 intervals on PCs, (large gears) It feels like mashing to me. I dont know about vectors , angles and oclocks, but I am pretty sure there are no dead spots.
We know PC's are changing the pedaling coordination as people train with them. I anticipate that once the study is done it will show that we are also changing the direction of all the forces to make everything more efficient in addition to simply unweighting the backstroke. But, the nice thing about PC's from the users perspective is you don't have to think about anything (at least after the first day or so). It is it is like learning how to pedal all over again, just like when you were a kid, except this time you are attached to the pedals. You are again learning through trial and error what works and what doesn't and you will subtly adapt to the coordination that is best for you without needing to think about anything.Billsworld said:
People who argue that pedaling style doesn't matter have never considered how they got to the style they currently have and have, probably, never trained with PowerCranks.
i agree that there is a difference between the riders perception of what they are doing and what they are actually doing... for example i found that if i imagine pedalling almost like i am doing classic x-country skiing (forward and back) and consiously think about pushing down at about 2 o'clock and keeping constant pressure until i unweight (leg actually feels like it's doing a diagonal from 6 o'clock to 2 o'clock... not pulling up.. just float the leg up) and while each leg is pushing made sure that it is torquing (i.e. no dead spots) that results in more watts for percieved effort...n crowley said:
then i found that if i don't even think about how i'm pedalling at all, i can think about pedalling any old way that feels good at the monent but just think about making my feet mimic the action of ones hands when spinning a wheel quicly and a constant speed.. and only consentrate on spining the cranks at that constant pace that works... more watts to perceive effort...
I'm not sure where the emergency stop in a car analogy came from, as you normally don't drive with your foot on the brake pedal whilst driving and nearly all people use their right foot which means the foot has to come up from the gas, across 6 to 12 inches and then down again.... Unless of course you have a racing license and have spent considerable time and effort to learn how to brake with your left foot, then you keep your foot over the brake and just move it too press the clutch every once in a while. Then you just have to worry about the guy, or in my case the woman putting on makeup and talking on her cellphone, behind who's going to rear end your car in the case of an emergency stop....n crowley said:
"I anticipate that once the study is done it will show that we are also changing the direction of all the forces to make everything more efficient in addition to simply unweighting the backstroke."
After the initial 2 months of hipflexor nightmares of learning how to pull up I've found that the quads have been talking a beating on learning how to push over the top of the pedal stroke and my hamstrings are just weak. On long climbs the downward push is more like hamstring squeeze from hell. It's almost like I've gone from feeling like I was getting stronger again to putting Powercranks on and feeling like an "old man with a walking stick" despite going measurably quicker the past couple of months.
I'm not sure I want to put a regular set of cranks on now... My brain would just become completely discombobulated....
The best part is my lower back is feeling better than it has done in years.... Now if only I could stand up and pedal - boy have I tried but even on a constant 14% slope I can't do it! Weight all the way forward and simulanteously pull across the bottom and push across the top.... I end up doing one legged standing pedal drills. Thank God my saddle is way comfy!
... and I'm sure there's a way to make the Basic Adjustable cranks about 5lbs lighter per crank and still have something as rigid as a 2 ton slab of granite!
LOL
It seems to me that once you get adapted or whatever you call it, the action seems the same. Lots of downforce where you expect it and less negative torque everywhere else.Fday said:
the action may "seem the same", in that the legs are going up and down and the feet are moving around and around, but I suspect the specifics of what is causing the movement is quite different since the feet are constrained so are everything is forced to move the same regardless of the muscle forces.Billsworld said:
I guess the queston you raise are two. 1. What are the changes required to "adapt" to the PC's? And, 2. How long does "adaption" take?
There have to be substantial changes or, otherwise, it would not be possible to explain the huge benefits most users report (and the studies are beginning to confirm).
Regarding adaption, I suspect it is an ongoing process with minimal adaption requiring only a few months but further adaption and improvements occur for several years.
Time and more studies should answer the above questions.
To learn how to pedal out of the saddle perhaps you should try it on the trainer. Put moderate resistance on the bike then control pedal speed by putting most of your body weight on the handlebars. The key is controlling pedal speed while you are working on the coordination. Concentrate on not stopping at the bottom of the stroke. Once you get it the first time, then subsequent times will come much easier and will start to become natural, even at higher power.swampy1970 said:I'm not sure where the emergency stop in a car analogy came from, as you normally don't drive with your foot on the brake pedal whilst driving and nearly all people use their right foot which means the foot has to come up from the gas, across 6 to 12 inches and then down again.... Unless of course you have a racing license and have spent considerable time and effort to learn how to brake with your left foot, then you keep your foot over the brake and just move it too press the clutch every once in a while. Then you just have to worry about the guy, or in my case the woman putting on makeup and talking on her cellphone, behind who's going to rear end your car in the case of an emergency stop....
"I anticipate that once the study is done it will show that we are also changing the direction of all the forces to make everything more efficient in addition to simply unweighting the backstroke."
After the initial 2 months of hipflexor nightmares of learning how to pull up I've found that the quads have been talking a beating on learning how to push over the top of the pedal stroke and my hamstrings are just weak. On long climbs the downward push is more like hamstring squeeze from hell. It's almost like I've gone from feeling like I was getting stronger again to putting Powercranks on and feeling like an "old man with a walking stick" despite going measurably quicker the past couple of months.
I'm not sure I want to put a regular set of cranks on now... My brain would just become completely discombobulated....
The best part is my lower back is feeling better than it has done in years.... Now if only I could stand up and pedal - boy have I tried but even on a constant 14% slope I can't do it! Weight all the way forward and simulanteously pull across the bottom and push across the top.... I end up doing one legged standing pedal drills. Thank God my saddle is way comfy!
... and I'm sure there's a way to make the Basic Adjustable cranks about 5lbs lighter per crank and still have something as rigid as a 2 ton slab of granite!
Saw a fancy CF lay-down recumbent today with a "ROTOR" crankset. These was something totally new to me. The owner said it really helped him smooth out his spin and eliminate the "dead spots". Apparently they allow the crank arm to move ahead freely for a few degrees at the top, effectively "flopping over" TDC so that the arms are phased at <180*, thus allowing the downstroke to begin early.
The ROTOR website cites studies which show power and efficiency improvements (of course). Wonder if anyone has experience with these cranks? At 1300 grams and $800 USD, they certainly aren't light or cheap, but the promise of free power is always hard to ignore I suppose.
The ROTOR website cites studies which show power and efficiency improvements (of course). Wonder if anyone has experience with these cranks? At 1300 grams and $800 USD, they certainly aren't light or cheap, but the promise of free power is always hard to ignore I suppose.
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