Rotor cranks VS Powercranks

velomanct said:

i have heard some good reviews about both of these cranks which are designed to make you elimate the dead spots in your pedal stroke. i am wondering if the reviews are biased. rotor cranks are reviewed on timetrial.com.

any opinions?

Here are a few other reviews:

http://www.cyclingnews.com/tech.php?id=tech/2004/reviews/rotor_rs4

http://www.mountainbike.com/gear/article/1,4823,7402_602,00.html&e=7627

http://www.totalbike.com/reviews/rotor.html

http://www.bikemagic.com/news/article.asp?UAN=3966&v=2

Gary Tingley
www.RotorCranks.com

Gary Tingley said:

Here are a few other reviews:

http://www.cyclingnews.com/tech.php?id=tech/2004/reviews/rotor_rs4

http://www.mountainbike.com/gear/article/1,4823,7402_602,00.html&e=7627

http://www.totalbike.com/reviews/rotor.html

http://www.bikemagic.com/news/article.asp?UAN=3966&v=2

Gary Tingley
www.RotorCranks.com

Here’s a couple of more links focusing on powercranks:

http://www.cyclingnews.com/tech.php?id=tech/2003/reviews/PowerCranks

http://www.fact-canada.com/Powercranks/powercranks-independent-cranks.html

The Powercranks are a training tool, not a competition/touring crank.

Each crank arm has its own freewheel bearings on the BB so each arm can one way clutch the bottom bracket forward and train the legs to operate independently and hence train to operate more optimally.

Rotorcranks are cam actuated cranks that change the effective chainring size as a function of leg position to the optimal effective size. Each leg does so independent of the other.

Rotorcranks eliminates the dead spot because the legs are no longer 180 degrees out of phase.

It is possible to eliminate a dead spot with Powercranks by backpedaling one leg or retarding a leg to change the phase relationship of the leg, but except at very slow speeds that is not a benefit.

meb said:

Here’s a couple of more links focusing on powercranks:

http://www.cyclingnews.com/tech.php?id=tech/2003/reviews/PowerCranks

http://www.fact-canada.com/Powercranks/powercranks-independent-cranks.html

The Powercranks are a training tool, not a competition/touring crank.

Each crank arm has its own freewheel bearings on the BB so each arm can one way clutch the bottom bracket forward and train the legs to operate independently and hence train to operate more optimally.

Rotorcranks are cam actuated cranks that change the effective chainring size as a function of leg position to the optimal effective size. Each leg does so independent of the other.

Rotorcranks eliminates the dead spot because the legs are no longer 180 degrees out of phase.

It is possible to eliminate a dead spot with Powercranks by backpedaling one leg or retarding a leg to change the phase relationship of the leg, but except at very slow speeds that is not a benefit.

The difference between the two systems-

How Rotor Cranks work - and the benefits:

Rotor Cranks work by increasing the force required on the drive side crankarm which propels the non-drive crank are past the 12 o'clock point ... also known as the dead spot/point. This happens 180 times a minute in a 90RPM ride. Or about 10,000 times an hour. The cyclist is now "permanently pushing" the cranks as there is no gap between when the legs take over push/recover duties, otherwise known as the dead spot/point. This elimination of the dead spot/point reduces the accumulation of lactate in the blood by 13-15%, and allows the rider to raise their level of wattage output before reaching lactate threshold. For many riders the increase in speed speed is in the amount of 2-3 minutes per 40k. Rotor Cranks also reduce cardiac effort (for the same level of effort with traditional cranks), and improve the health of a cyclists knees.

How Powercranks work - and the benefits:

PowerCranks teach your neurologic system to unconsciously "pedal in circles." By pedaling in circles, more of the energy you are now expending actually gets to the wheel. For the same overall effort, the more efficiently you pedal, the faster you go. So the cyclist gets more efficient use of the muscles he/she has already trained and, as noted above, the ability to incorporate new muscle mass into the now unused portions of the pedal stroke. Powercranks are based on "pulling" up on the pedal stroke using the weaker hip flexor muscles. Unlike normal cranks, each crank arm spins independently of one another.

Difference between Rotor Cranks and Powercranks:

Rotor Cranks eliminate the dead spot, allowing for "permanent push" to the pedals, making legs efficient at what they do best: pushing. This allows for lowered lactate levels and increased wattage at LT, which translates directly to the 2-3 minute per 40k speed increase. They are scientifically proven to reduce lactate levels, reduce cardiac effort, and improve the health of a cyclists knees by eliminating the dead spot.

Powercranks gives you an immediate feedback system as to when you start to pedal improperly so you can retrain your neurological system to fire your muscles in a different coordination changing the pedaling dynamic to improve pedaling efficiency. They are great for developing a smooth and efficient spin and are a much better alternative than one-leg pedaling drills. They improve the strength of hip flexor muscles which benefit running and "lifting the leg".

Gary Tingley
www.RotorCranks.com