Truth about clipless pedals, Q-rings and everything

Discussion in 'Cycling Equipment' started by jawnn, Apr 3, 2007.

  1. jawnn

    jawnn New Member

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    As a mechanical engineer and car free commuter, I am always looking for something to improve the interface between my aging legs and my drive wheels (not for racing). People keep telling me that I should use cleats to pull up the pedals. But in reality most people can’t really pull hard enough to make much of a difference.


    It ‘may’ help racers, but for most people the weight of the lifting leg is still about 20% of the push from the other side. Human legs were never developed to lift much weight; it would be better to lift the recoil side foot off the pedal momentarily if you can keep your foot in the right place (easier to do with cleats).

    Power Saver pedal pendulums reduce the lift by 40mm. But nothing is perfect, they need your foot attached to the pedals, and you can’t ‘pull up’.

    There was a test done by one of the cycling magazines about 10 to 12 years ago. They rigged a number of bikes with load cells on the pedals to read pressure pulling and pushing. The riders were a mix of everything from average Joes to Cat. 5,4,3,2,and,1 racers, Iron-Man triatheletes and pro-tour racers. Even though most of the riders felt like they pulled up a considerable amount the test showed that only a few of the very elite riders pulled up enough to make a measurable difference.

    “Spinning” with BMX pedals is easy with the crank out in front of you because gravity helps pull the foot down threw the dead zone and back, on recumbent bikes.


    The only thing that makes the Q rings different from every other asymmetrical chain ring is the degree of adjustability and more aggressive recommended position.

    Biopace works at a slower speed (about 80rpm) because they rely on momentum and actually like I’m not pushing as far. But the Q-rings are positioned to power threw the dead zone.

    After riding in the rain, my new Q-rings started oxidizing severely, I had to spray varnish on them to try to stop it, but this did not stop it, they continued to oxidize under the cheap plating, they are fixing the problem but people should refuse to pay more than $50 for each of the chain rings. In fact they shouldn’t bother with them at all until they have trained and developed a good fast cadence. Power Cranks are the best training tool; Q rings are not a training tool, they may compensate for the inability to pull up hard enough, but to what degree?

    Rotor Cranks may be useless for “Lance-wanta-be’s” but I think it may be the best thing for commuters with bad knees (other than just using lower gears); even if it was invented over one hundred years ago.

    Mechanical aids are a poor substitute for good spin technique. The only way to know for sure that your getting more energy to the drive wheel is to use load sensors on the pedals in conjunction with a Power Tap watt reading system compared with cadence and speed.

    I would like to see comparison data on the various devices, including short cranks and linier push power systems like the K-Drive that lets you push and pull at the same time.
     
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