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Old 12-30-03, 03:18 PM   #1
bac
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Powercranks

I did a search, and read a little about Powercranks. Has anyone (Koffee - I saw that you did) used these? Does anyone own these? The videos are worth a look - even if you don't care about this product. FYI, I have no affiliation with this company, I'm just interested. ThanX!

Powercranks
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Old 12-30-03, 04:24 PM   #2
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Hey Bac-

Yeah, I seriously considered getting the powercranks. I do believe they do work as they are supposed to- increasing the strength of your hip flexors so that you have a smoother pedal stroke.

You can easily do this on your own. If you have a trainer, put a box about a little higher than pedal height next to one side (say, the right side). Then you pedal only with the left foot, while the right foot remains on the box. This forces your hip flexors to do a bit more work.

You don't need to pay $700- 1000 for something when you can get an old box or crate from the basement and get almost the same results for free.

Koffee
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Old 12-30-03, 05:14 PM   #3
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This recent study might be of use. They use the term "significant" but not "statistically significant", which might be worth noting since the SEs or SDs for GE overlap. If I had the cash I'd buy a Power Tap instead and keep doing ILT like Koffee suggested.

J Strength Cond Res. 2003 Nov;17(4):785-91.

Effects of short-term training using powercranks on cardiovascular fitness and cycling efficiency.

Luttrell MD, Potteiger JA.

Department of Health, Sport and Exercise Science, University of Kansas, Lawrence 66045, USA.

Powercranks use a specially designed clutch to promote independent pedal work by each leg during cycling. We examined the effects of 6 wk of training on cyclists using Powercranks (n=6) or normal cranks (n=6) on maximal oxygen consumption (VO2max) and anaerobic threshold (AT) during a graded exercise test (GXT), and heart rate (HR), oxygen consumption (VO2), respiratory exchange ration (RER), and gross efficiency (GE) during a 1-hour submaximal ride at a constant load. Subjects trained at 70% of VO2max for 1 h.d(-1), 3 d.wk(-1), for 6 weeks. The GXT and 1-hour submaximal ride were performed using normal cranks pretraining and posttraining. The 1-hour submaximal ride was performed at an intensity equal to approximately 69% of pretraining VO2max with VO2, RER, GE, and HR determined at 15-minute intervals during the ride. No differences were observed between or within groups for VO2max or AT during the GXT. The Powercranks group had significantly higher GE values than the normal cranks group (23.6 +/- 1.3% versus 21.3 +/- 1.7%, and 23.9 +/- 1.4% versus 21.0 +/- 1.9% at 45 and 60 min, respectively), and significantly lower HR at 30, 45, and 60 minutes and VO2 at 45 and 60 minutes during the 1-hour submaximal ride posttraining. It appears that 6 weeks of training with Powercranks induced physiological adaptations that reduced energy expenditure during a 1-hour submaximal ride.

Last edited by nhorscro; 12-30-03 at 05:20 PM.
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Old 12-30-03, 05:33 PM   #4
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I also came across this study. They don't call them Powercranks but the principle seems the same. The data is pretty similar too....and once again they don't call it statistically significant.

Med Sci Sports Exerc. 2002 Nov;34(11):1854-8.

A new pedaling design: the Rotor--effects on cycling performance.

Santalla A, Manzano JM, Perez M, Lucia A.

Universidad Alfonso X El Sabio, Madrid, Spain.

PURPOSE: To assess the effects of the Rotor (ROT), a new pedaling system that makes each pedal independent from the other so that cranks are no longer fixed at 180 degrees, on endurance cycling performance. METHODS: Following a randomized design, eight subjects (noncyclists; age (mean +/- SEM): 22 +/- 1 yr; VO(2max): 51.8 +/- 1.0 mL x kg(-1) x min(-1)) performed two bicycle-ergometer tests on separate days, one with the conventional pedaling system (CON) and the other one with ROT. Starting at 75 W, the power output was increased by 25 W at 3-min intervals until volitional exhaustion. Gas exchange parameters and blood lactate were measured for every 3-min interval. RESULTS: At exercise intensities between 60 and 90% VO(2max), delta efficiency (DE) was significantly higher in ROT than in CON (24.4 +/- 1.9% vs 21.1 +/- 1.1%, respectively). CONCLUSIONS: Although more research is needed, especially with trained riders, the Rotor system might improve delta efficiency during endurance cycling. Other performance determinants VO(2max), maximal power output) do not seem to be changed compared with the conventional system.
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Old 12-30-03, 08:05 PM   #5
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It sure is odd looking to see someone coasting with both cranks down.
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Old 01-02-04, 02:05 PM   #6
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Quote:
Originally Posted by Koffee Brown
Hey Bac-

Yeah, I seriously considered getting the powercranks. I do believe they do work as they are supposed to- increasing the strength of your hip flexors so that you have a smoother pedal stroke.

You can easily do this on your own. If you have a trainer, put a box about a little higher than pedal height next to one side (say, the right side). Then you pedal only with the left foot, while the right foot remains on the box. This forces your hip flexors to do a bit more work.

You don't need to pay $700- 1000 for something when you can get an old box or crate from the basement and get almost the same results for free.

Koffee
Koffee, A while ago you was talking about purchasing a trainer. I was wandering, Which did you finally end up choosing???...
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Old 01-02-04, 03:54 PM   #7
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I got the CycleOps Fluid 2 Trainer. It still needs assembling (I can't figure out how to do it), but I'm ready to go when I can get someone over here to put it together for me!

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Old 01-02-04, 09:44 PM   #8
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Koffee,

I have a fluid 2 also, what ya need to know about
assembly? its pretty straightforward.
PM me and I'll see if I can talk ya through it.

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Old 01-02-04, 10:47 PM   #9
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Dude, I'll pm you, but I couldn't put two popsicle sticks together to save my life. I just don't have that kind of spatial ability.

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Old 01-03-04, 01:16 AM   #10
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Looks like a really great product, but with a $700 price tag I think I'll stick to one leg drills.

A thought that just occurred to me. What if a standard left crank was mounted to match the right crank, not point in the opposite direction? This would bring both feet to an identical point throughout the pedal rotation. Would this have the same effect as one-leg pedalling, but on both legs?

Mike
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Old 01-03-04, 05:49 AM   #11
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Quote:
You can easily do this on your own. If you have a trainer, put a box about a little higher than pedal height next to one side (say, the right side). Then you pedal only with the left foot, while the right foot remains on the box. This forces your hip flexors to do a bit more work.
Couldn't this be achived on the road by alternating between the left & right legs doing intervals???...
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Old 01-03-04, 06:04 AM   #12
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Quote:
Originally Posted by meltable
What if a standard left crank was mounted to match the right crank, not point in the opposite direction?
Seems like you might hurt your nads on the back half of the pedal stroke.

-s
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Old 01-03-04, 03:07 PM   #13
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Originally Posted by Vitamin X
Couldn't this be achived on the road by alternating between the left & right legs doing intervals???...
Totally. I just tend to cheat when I do them on the road, but I definitely do that. I also advocate doing it in cycling classes too- my students do it, since we can't put a box next to each of the indoor cycling bikes.

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