Comparison test done PC vs Regular cranks

Triathlon Forum
34

Not a PCer wrote: You’re also fooling yourself if you think that pulling the leg up using the hip flexors somehow adds more driving torque to the rear wheel than just pushing the leg up by pushing down on the opposite pedal. That would be true only if overall energy expenditure increased, but if that’s the case then the same thing could be accomplished by simply stomping down harder as well.

Its simple. Let’s say for arguement’s sake, that I push down 40lbs with my right leg, and I use up 2 lbs. of that push to lift my left leg with that right leg. That leaves 38 lbs. of push to the drivetrain.

On PC’s, you CANNOT waste any of that power to lift the left leg, so you get the entire 40 lbs. of force to the drive train. More force to the drivetrain equals more speed, right?

At the moment, I apparently haven’t made an adaptation great enough to accomplish this for long periods of time. I’m willing to work at it for quite a while to see if I can do it. If I can exceed just lifting my left leg and actually ADD, let’s say 1 lb. of force to the stroke by lifting my leg plus 1 lb., I’ll now have 41 lbs. of power going to the drivetrain instead of only 38 lbs.

I really don’t see what’s so hard to understand about that.

Furthermore, to say that unless I get an almost immediate improvement, then I won’t get an improvement, is absurd. Think of it like this…If I wanted to high jump 6 feet, and I started at only clearing 3 feet, then worked hard for two months and could only jump 5 feet high, does that mean I’ll never get to 6 feet? NO! It means I still have more work to do. I may or may not ever jump 6 feet, but it doesn’t mean I’m doing the wrong training for it.

You throw around several comments about track sprinters that I’m not sure are really true, but I have no way of knowing what is actually happening with a track sprinter’s power system. I will say that unequivocally, if a sprinter did more effectively use his pulling up muscles while maintaining his same pushing down muscle force, he would have more power applied to the drivetrain.

There was also a comment that Mr. Armstrong doesn’t need PC’s or use them. Have you asked him? I happened to have the pleasure of talking to him in person in December when he came through town…I asked him about PC’s as my buddy (that got me tickets to the Linear Accelerator for Brain Tumor treatment dedication) handed him a 6 pack of Shiner Bock Beer in the back hall. I will tell you he was careful with his response, and that he knows what they are. But, that’s all I’ll say, it was a private conversation meant to stay private.

I’m off to ride now. On my PC’s.

36

You still don’t get it. If 40 lbs. of force is all those muscle fiber units are capable of doing for long periods without going into oxygen debt, you can’t just push down 2 more lbs. of force to yield 42 lbs. of force for long. The answer is to recruit other muscles to provide that 2 lbs. of force. Hip flexors, in this case.

That’s not an apples-to-oranges comparison.

38

It is true that one can pedal efficiently without Powercranks. Just as someone can swim without a coach, but that does not mean that Powercranks or a coach are without value. People can debate whether to race on regular cranks or Powercranks.

Few can honestly debate whether Powercranks assist one in learning to, at the very least, eliminate resistance on the upstroke. This in itself can create more speed for a given effort.

I haven’t yet heard anyone debate whether Powercranks can help improve one’s running. Isn’t this a triathlon board? If so, wouldn’t Powercranks have value even if they did not improve one’s bike leg at all, but only helped with the run?

I doubt that many of the pro’s “need” Powercranks to simply improve their bike, perhaps their greatest immediate benefit is on the run. I would still think that valuable.

People can debate the relative cost of Powercranks, no different than the cost of a top fitting, an expensive bike, a masters’ swim program, or coaching. Let each decide where the cost/benefit lies.

I’ve been on Powercranks for the past 3 months and wouldn’t return or sell them for the world. I’m not paid in any way by Mr. Day. I just think that people should realize the possible benefit. How much will you pay for a set of race wheels? What do these give you, maybe 0.5 mph benefit? Between the bike and run legs, I guarantee that Powercranks offer more.

Regards,

Daniel.

39

Francois,

First of all, my doctorate (when I get it in june) is a clinical medical degree, not a phd. However, I do have a masters (and significant work towards a phd) in molecular genetics. So I have a pretty good idea of how science works, and pretty good BS filters. I do not take everything I have learned as gold, but I do take it as a good place to begin. That is how science works. You are always building on the foundation of others. I was trying to keep my response pretty basic, because I know many of the people here do not have an extensive background in physiology and there is no reason to be difficult to read. So I will be more direct this time.

  1. Which muscles are better anatomically adapted to the motions of cycling? The extensors.

  2. Which muscle group is operating at a better place on it’s length tension curve? The extensors.

  3. Are you recruiting every muscle unit in the extensors while riding? No. (although I don’t remember the percentage, you are nowhere near full recruitment until you are in a full on sprint)

  4. Does it make more sense to use a muscle inefficiently (the flexors) in a range of motion that is not optimal given their origin, insertion, and angle, when there is a very well developed, very efficient extensor group on the opposite side of the bike that is NOT HAVING ALL OF IT’S FIBERS UTILIZED? No.

  5. I may or may not be correct about the pull across the bottom of the stroke…an anatomist once explained to me that there are significant gains to be made their through use of the glutes as they are still in a good place on their length tension curve. I was told cyclists are often more powerful in a more rearward position for this reason. I have never read on this myself.

Again, the power crank argument makes sense only when you have used every single motor unit in the extensor group. At this point, added units from the flexors, even if they are being inefficient, are helpful. The germane argument is this: are you being more efficient if you are putting out 200 watts from a given leg, and twenty of those watts are from the flexors, if you still have fifty watts of unused potential in the extensors? No, because you are using a relatively weak muscle in a range of motion outside it’s optimum, and you have the potential to get a lot more work out of another muscle group which IS in is best range of motion.

And your argument re: forearm muscles is ridiculous, I am sorry to say. The forearm muscles are nessecary to fix the wrist during the catch and pull phase of the stroke. There are no other muscle groups to use. In the bike, there are OTHER, better developed and better adapted muscles in use, which are NOT being used to full potential. Period. Your argument re: the forearm would only make sense if there were other muscles to use.

and finally, I don’t know what kind of doctor you have over there, but over here it is pretty well known that surgery is generally not the best management for chondromalacia.

Philbert

41

I can’t believe I’m posting since I hate the debates on this topic. You know the ones where everyone becomes an instant expert? So all I’ll do is post some assumptions and some questions.

Assumptions:

I always assumed that PC’s helped develop a more efficient pedal stroke, not necessarily a more powerful one.

I also assumed that the role of using the hip flexors in the manner the cranks force you to is NOT to add more power to the drivetrain, but to make it more efficient since more (all) of the force generated by the powerful extending leg goes into turning the wheel instead of turning the wheel AND lifting the recovering leg.

I think it is a fair assumption that as a cyclist’s pedal stroke becomes more efficient, it sets him up for increased speed. (Much like swimming efficiency.)

Questions:

PCs are a technique tool. Why jump all over people for trying too improve their cycling technique (instead of just their power or endurance) but not do the same for swimming?

If training with PC makes you more efficient, why is this bad?

Do those who are bagging on PC’s also feel that the Spinscan feature of a Computrainer is stupid? Why / why not?

I look forward to more of these reports from ktalon as I’m interested to see if he becomes more efficient on the regular cranks over time. Of course this will be anecdotal, is not a controlled test, and there will be some training effect, but I’m interested nonetheless. I really don’t care how one performs on the PCs versus regular cranks. I care about how the usage of regular cranks improves over time and how this may be benefitted by PCs.

43

i have a question for the “extensor” crowd. that is: why do you think you use your extensors LESS with PC’s? that is not my impression riding them at all. if the extensors are " all that" that is fine- i use them as much with PC’s as i do without. the differnce is now that i have developed better and more efficient use of the flexors i can now use the extensors for fully driving the wheel, as opposed to driving the wheel and lifting/moving the other leg. how can this be seen as worse ? what am i missing in your biomechanical argument?

the swimming anaolgy keeps coming to mind. if i get more slippery in the water do i use my driving arms less ? no. then why would i use my extensors less as i pedal more fully?

45

oh, and one other thing - have you guys ever used them? i am not claiming to be anything other than guy who spends way too much time enjoying his bikes - but i think the issue of whether you have actually used them or are simply posing theoretical quandries is apprapo. most everybody who has used them loves them, or at least will say they did notable good for them. this is significant, given that thse same guys could have sent them back after two months. for those still on the fence i would weigh this fairly significantly. . . . . . . .

47

…on a related note, after reading that last reatise. . . … where do you fella’s come down on bio-pace ?? seems to me we read an awful lot of junk sounding very similar to that buisness about fiber recruitment and percent this and angle of effectiveness that back when the brains gave us bio-pace. those dudes didn’t ride it, either by the available evidence. in the end the experiencal crowd won the day, not the theorists. round was better. in the case of PC’s i believe the experiencial crowd is in the camp that has, for a hundred years sought to pedal in circles and get the other leg out of the way. now we have a way to do that while …riding our bicycles ( imagine). try some, and then get back to me. i’m out.

48

WOW! These are quite some statements!

  1. “It deludes people into believing that pedaling a bicycle is a complex motor task that takes much practice to master.”

  2. “…and specifically that “pedaling in circles” is a desirable goal.”

And I thought Powercranks were innovative! So you’re telling me that hundreds, indeed thousands, of professional cyclists on road, cyclocross, track, mountain bikes, not to mention professional duathletes and triathletes have been doing it wrong. One-legged drills, Computrainer, fixed gear bikes, all of these are being used as tools to pedal more efficiently. Really, Powercranks are very close to providing you the experience of one-legged drills, but simultaneously for both legs, so it can be more rigorous and time-efficient.

Perhaps pedaling in the “most perfect” circles is not desirable for everyone, esp. if it reduces their very high power output. But you don’t have to pedal in “perfect” circles in order to use Powercranks. You just have to pedal more efficiently than you probably have been before.

Are you aware that some of the best cyclists in the world (Div. I pro) are using Powercranks in Europe, for at least some portion of their training? Sure, I look forward to more in-depth testing of Powercranks to determine their most effective use. Do you require double-blind study results before you buy a new bike, new race wheels, a coach, etc? Powercranks cost less than a high-end drivetrain.

Isn’t it a bit spineless to post anonymously, “not a PCer”?

Regards,

Daniel.

49

Pooks,

I don;t mean to bag on people for using PC’s, and I am sorry if it comes across that way. If PC’s cause an improvement, for whatever reason, even if only because you have to spend more time on your bike to master them, or because it makes you think about your workout more rather than daydreaming a little and not going as hard as you should, then that is a good thing. Our goal is to be faster. My real problems with them are that:

  1. there is a fair bit of pseusoscience associated with their promotion, and it might be difficult for the average person without education in those specific subjects to recognize that. Sort of like with certain supplement manufacturers promise. I just don’t think it is fair. If a person read through all of these arguments here and decided, “I understand all the scientific arguments as to why these should not work, and am willing to give them a try”, then I have no problem with that. Do you see what I mean?

  2. I am a student, and a scientist. The first means I have very little money, the second means that I would rather stick with what is known to work for the task at hand. I do not know that PC’s will be a good training aid without trying them, and if I did, I would always wonder, ‘could I have realized the same benefit by training more?’. I DO know that if I manage to save up for a Power Tap, that the advantages of power based training are well documented and that I can feel confident that I will realize those benefits by applying the proper training program. For me, I guess it is both economic and psychological: I’m not interested in being a test subject in my own little experiment. I know what IS proven today, so that is the way I feel I need to go.

As a scientist and doctor I feel I have a responsibility to practice in my own life what is “evidence-based”…a new experimental drug might work, but I am not going to try it myself, or prescribe it for you, until there is a large amount of evidence to say that it is a good idea. Power based training is largely agreed upon as the best way to go, so that is where I put my interest and $$$. But I feel everyone should be able to make an informed decision for themselves.

Francois: I do not honestly know what percentage of motor units can possibly be recruited. I will try to read on that. You may be right to assume that you cannot continually recruit more of them for long periods of time. That would be a good question for Dr. Coggan, wherever he may be.

Philbert

53

providing you guys ride, i encourage you to try some (keep that mind open , now), and get back to us.

here’s a tip on crow, provided you accept - it is best eaten warm.

54

oh hey !! this just in from the judges:

bonus points to me for correctly guessing you guys were bio=pace sympathizers. . . .

55

Philbert, first off my post wasn’t directed at any particular person, so you’ve got no reason to apologize. I guess I’m reacting to the general vibe this board tends to take on the PC discussion.

On your first point, I completely agree. There’s a ton of psuedo-science being weilded here. BUT, it’s not just those promoting the cranks. It’s from both sides.

I think watching these debates is funny. There are a group of guys on this site that are trying out a new training tool in hopes that they’ll see some substantial improvements in their cycling. They perform some simple tests and share the results. They share their experiences, both good and bad. Basically, they’ve willingly become guiney pigs in an experiment to find a better way to train. Does anyone else here see the potential benefit here?? Rather than making suggestions to these guys about how they could improve their tests or maybe get clearer results to help us understand what PowerCranks actually do, we send abuse their way and write things off as BS.

I understand that much of what people have a problem with is the marketing claims of the cranks and how they are marketed on this site. In almost all other cases of product marketing, the posters on this forum ignore marketing and pass it off as “marketing hype”. We look past the hype and care about the product itself. Why can’t we do that in this case?

There’s this new type of cranks on the market. They’re pretty hard to use initially, but people who use them tend to believe that the cranks make them a better cyclist and runner. Rather than saying “that’s BS”, I’d rather find out if it’s true.

My take is that what these posts do is help people decide whether the cranks actually provide benefits that they would be willing to pay for.

57

no, i was trying to make a little funny directed at the extensor guys, francois, mr non and his buddy. carry on pardner.

58

Ktalon,

I find one major flaw in your test procedure. Stopping to let your HR down throws a larger error into the measurement. The only way for this test to really be meaningful is if you can maintain pedaling & keep you HR in range for the entire period. If each of the 15 stops was only 12 seconds you automatically lost a mile, without calculating the time to get back up to speed. Since you were waiting for your HR to go down5 BPM & HR has a inherent delay, I would guess that you were waiting more like 20-30 seconds. This very easily explains the difference between total miles.

I would consider your results completely meaningless until you are able to pedal the entire 60 minutes for both tests.

60

Goatboy, you are entirely correct, that was a major flaw. I’m sure that there are other flaws, it was just a first-try guess at trying to do a test.

61

Dr. Coggan is on bicyclesports.com’s forum, as am I, … do you mean to tell me you have a problem with the following … I thought that PC’s wouls make me 80% faster over 2 years with no additional training time required… I wonder where I got that idea?

The following is the most BS PC info I have ever read, hell, even I was lured to believing it at first. 80%+ power impovement in 2 years with no addition time required on the bike?

Then I researched it and found out where leg power really comes from … and it’s not the flexors. I’m back to riding at 90 RPM and pushing a 54/16 on the flats. Works best for me. I also ride in the Slam position, works very well for me. (props to J.C. on that one)

Powercranks ad copy:

“By training with PowerCranks™ one can easily train these important muscles without any additional time commitment, making the time you are now spending training, more effective and efficient. Our data indicates the typical cyclist/triathlete can increase power on the bicycle 40% (that’s 2-3 mph faster on the road for most) and the typical runner can take 20 minutes off their marathon time in less than one season. Further, it seems that second year improvement can be just as dramatic, if not more so.”

62

Not a PC’er. When you make comments like that, it simply shows me you don’t pay attention to read the whole thing. I stated that this piddly test was done at a HR of 150 maximum. It wasn’t all out. It wasn’t even at a HR that I race.

The thing you STILL don’t get, is this: Once your extensors are operating at their maximum efficiency for a time trial (not a sprint, not a dead lift, etc.), that level of work is all they are able to do without going anaerobic. Yes, you can train them to do more work before going anaerobic in various manners. AGAIN, let’s say you’ve done this to the best of you ability for years and have hit a plateau. NOW, IF you can remove the effort that those extensors are expending by LIFTING YOUR LEG with your hip extensors, more power goes to the drivetrain. If you still don’t understand, I’ll draw a picture with a fulcrum and see if that helps.

63

Gary, we get it, you have issues with the PowerCranks marketing claims. I find it fascinating that this is the only company who’s marketing you seem to have a problem with. After all, doesn’t just about every frame manufacturer claim they make the fastest frame on the planet? Why don’t you get a burr up your ass about that???

The guys on this board who are using PCs are trying to figure out how and how much PCs benefit them if at all. They are not the ones writing the ad copy for PCs. Why do you have such a problem with this???

For someone who is “outta here”, you sure make a lot of posts. Enough with the trolling already!

64

OK, a math test for Gary. 40% of a value, plus 40% of the new value, does not equal 80%.

Sorry you were “taken in” by something you don’t understand, like math. I don’t know if the claims of 40% are true, but, if they are, it was claimed for the AVERAGE rider, not someone already as fast as you claim to be. And yes, there are posters on this board that have gained 40%, or more, in one year.