Powercrank results ... Are they any good??

[mlocke]

I think a few guys in the club have them.

What the verdict? Are they worth the ££?

Can you / do you use them regularly (in the unlocked position)?

Hoping to look at purchasing some nthe near future but they are a bit pricey to just splash out on based on the info from the website selling them.

Would a powermeter be a better investment?

Cheers

Locky

[-Adam-]

power meter!

pedalling isn't that hard! Just do some specific cadence work and you'll get the same benefit.

[Keith]

[quote="mlocke"]Would a powermeter be a better investment?

[Paul H]

I have both and would definately go for Powertap first.

The Powercranks do help but not as much as their silly advertising reckons. The first time I used them, I trashed my legs after about 10 mins and it would be very hard to get the same benefit any other way. Its like doing one leg riding all the time.

[Ivor]

powercranks always seem gimicky to me. I'd think you can get the same sort of workout pedalling one legged and practicing riding a fixed.
I used a polar power meter for a while and found it was pretty useful and interesting to see my power usage and how it changed.

[huw williams]

For your requirements Mark - Powertap would be more suitable

[Paul H]

[quote]I'd think you can get the same sort of workout pedalling one legged and practicing riding a fixed.

[George]

They really help you to get more power in your pedal stroke and you just start accelerating without knowing it by pushing a massive gear.
I commuted on mine every day for 3 months and I was cycling everywhere in 54/12
You really feel the lactic acid burn in your legs at all times.
Mine don't have the lockout so you have to build up to riding for more than an hour, once you really master them try doing the clubrun on them and boy thats tough.
People who tried riding on my bike couldn't last more than 5/10 mins
Come n ave a go if you think your ard enuf

[nick de meyer]

George is right, and to improve efficiency and remove dead spots you really need to perservere with Powercranks. It can be 1-3 months before you started seeing the benefits and results, have a look at www.powercranks.co.uk for more studies and info or follow powercranks uk on facebook. You want to start using powercranks in small doses, and gradually building up the time on them. Even the pros find them hard at first, eg, Levi leipheimer, george hincapie.

interesting article below

Effects of short-term training using powercranks on cardiovascular fitness and cycling efficiency.by
Mark D. Luttrell, and Jeffrey A.Potteiger

This is our most popular crank. It will fit 99% of all people out their and adapt to 99% of the bikes out there. It is built to give many years of service. Crank length is adjustable from 165 to 182.5 so it will be right for almost everyone

ABSTRACT

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 (O2max) and anaerobic threshold (AT) during a graded exercise test (GXT), and heart rate (HR), oxygen consumption ( O2), respiratory exchange ratio (RER), and gross efficiency (GE) during a 1-hour submaximal ride at a constant load. Subjects trained at 70% of O2max for 1 h/d, 3 d/wk, 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 O2max with O2, RER, GE, and HR determined at 15-minute intervals during the ride. No differences were observed between or within groups for O2max 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 O2 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.

Comment

This was the first study ever published on the PowerCranks. To be perfectly honest I didn't expect that such large benefits could be demonstrated in such a short period of time. Until this study the only way it had been thought that it was possible to improve cycling efficiency was through long term training to change muscle fiber type from fast twitch to more efficient slow twitch fibers. To see an overall 10% improvement in efficiency (21% to 23% is a 10% improvement) in 6 weeks is just huge. How this was manifest in terms almost every cyclist can understand is the PowerCranks group lowered their HR 15 bpm (from 165 to 150) at the same power in the post study test. While unexpected before we saw this result it can be explained. there are two ways we can hypthesize improved efficiency, changing the pedaling coordination and, as mentioned before, changing the muscle fiber type. Six weeks is enough for both these changes to start to occur.

Link to study: PubMed or at The Journal of Strength and Conditioning Research: Vol. 17, No. 4, pp. 785–791, pdf

[Ivor]

Alternatively:
Cycling efficiency and performance following short-term training using uncoupled cranks. - Andrew D Williams et al.
Int J Sports Physiol Perform 4(1):18-28 (2009)

CONCLUSION: Our results indicate that 6 weeks (18 sessions) of training using an uncoupled crank system does not result in changes in any physiological or performance measures in well-trained cyclists.

*Edit, added links*
Recent paper, with control and well defined groups:
[url]http://ecite.utas.edu.au/52288/1/Williams-et-al.--2009-.-Cycling-efficiency-using-uncoupled-cranks.pdf[/url]
In it they also speculate on the reasons for disparity in the Luttrell and Potteiger paper.

Another interesting one with some ideas about how powercranks affect the pedalling stroke:
[url]http://w4.ub.uni-konstanz.de/cpa/article/viewFile/3226/3028[/url]

[Dombo]

Alternatively, fit a dynamo powered light. Once oncoming cars start flashing you you're doing ok

[Dombo]

[quote="marco"]Nick, that study would be great if there was a control group to compare against otherwise it is unfortunately completely worthless. Its a shame because they've gone to the trouble of setting it up and putting the powercrank users on a particular training schedule so it wouldn't have been too hard to put a control group without powercranks on the same schedule and compare results.

[Andrew G]

[quote="Dombo"]Alternatively, fit a dynamo powered light. Once oncoming cars start flashing you you're doing ok

[-Adam-]

Or, stop f*****g about looking for quick fixes and shortcuts and do some painfully fast cadence work on a normal bike with normal cranks and small gears.Thats what I do, and thats what the pro's do who aren't being paid to bullsh*t on about how great power cranks are!

[Ivor]

Nicely put Adam.
although I do rather like Doms dynamo idea.