Peddling in circles?!?

lotus49

ethanhayes wrote:

If I am trying to move a weight by pushing it along the floor by my self I am going to see fatigue develop quicker than I would if I shared the work load with a mate, who was pulling the load I am also pushing.
The amount of force needed won't change, but less effort is expected from the engine.

Does this idea work in terms of cycling?
Where the weight is the rear pedal with the weight of a foot doing nothing but rest
My mate is my leg, pulling up on the rear pedal
and the engine is my front leg producing power on the front pedal

I'm not suggesting it does - I'm genuinely trying to get my head around this concept.
That doesn't need to translate into any sort of efficiency gain either.

The short answer is no, it doesn't work in terms of cycling. The main reason is that it's not a good analogy. In cycling you aren't sharing the work with someone else. Your legs are not fully independent and what you do with one affects the other.

In order to make your analogy more like cycling, your mate would be attached to a long rope that would be connected to your back by means of a pulley behind you. When he pulls the weight, he is also pulling you backwards. That is more or less what happens when people try to pull hard (ie more than enough to overcome the effect of gravity on their leg and actually produce power in the stroke). The effect of pulling up is not free as it has a negative effect on the other leg. This may not seem obvious but several sport scientists have made dynamic torque measurements using different pedalling styles and found this to be true.

In addition to this, legs are very ill-suited to pulling like this so not only is there no immediate gain, you are going to tire your legs out very quickly.

marz

lotus49 wrote:

marz wrote:

Having snapped off a few pedals in my time, I would not have been able to ride home without pulling up and producing power.

That simply isn't true. You pedalled by pushing on the downstroke and momentum carried you forward until you were able to push again.
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There is very little momentum in the cranks when pedaling with one foot. Your pedaling pedal is not going to lift up unless you at least unweight on the uplift and if you can unweight you can pull with some power.

You seem to have miss-read the current research, none of which says it is not possible to pull with some limited power. What the research is saying is that the pro's and experienced cyclists don't (not can't) pull up when riding and when asked to try and pull up there was an overall net loss in performance. The additional injection of power from lifting the pedal resulted in either a decrease in pushing power or a faster metabolic burn rate.

lotus49

marz wrote:

There is very little momentum in the cranks when pedaling with one foot. Your pedaling pedal is not going to lift up unless you at least unweight on the uplift and if you can unweight you can pull with some power.

You seem to have miss-read the current research, none of which says it is not possible to pull with some limited power. What the research is saying is that the pro's and experienced cyclists don't (not can't) pull up when riding and when asked to try and pull up there was an overall net loss in performance. The additional injection of power from lifting the pedal resulted in either a decrease in pushing power or a faster metabolic burn rate.

You have misunderstood my posts (or perhaps I haven't expressed myself very clearly). Clearly it is possible to lift your leg and I obviously didn't mean that. What I meant is essentially what you just said in the above paragraph. No net useful power is produced as a result of pulling up and no-one does it.

Consequently the whole "pulling on the upstroke" thing is a myth. It doesn't work so no-one does it.

Valy

Wheew, finally understand what both sides were trying to say!

You can pull on up on a pedal with one foot clipped in and make yourself go forward if you other leg is dangling even be it form a standing start.

Pulling up during normal pedalling does not add any more power or efficiency overall.
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Though I might add that on out of the saddle big accelerations I am convinced that I am pulling a lot on the pedals as well as pushing down.

thescouselander

I think there is a lot of misunderstanding going on here. Pulling up on the pedal will definitely give more power. It doesn't matter a jot what's happening with the other foot which is pressing down - if the foot going up places any upwards force on the pedal it will add to the total amount of torque in the crank (ie all forces are additive).

I know for a fact I can move from a standing start by pulling up with one foot clipped in so to say it does nothing is nonsensical to me. The effect might not be huge but its certainly enough to make a small difference. I certainly find this technique useful for very short periods when going up a steep hill.

freddiegrubb

As soon as I hit an incline push n pull is an auto reaction, it certainly feels like it. Perhaps I'm wrong.

Valy

Yeah completely agree. Just payed attention to it a bit more and definitely there is a pull when setting off or accelerating flat out etc and it add a significant amount of force. This whole thread is super easy to read wrong, I see where the no pulling comes in as well.

chrisaonabike

I don't know enough to have any view about whether pulling as well as pushing increases the available power, but I have found that brief periods (a few seconds at a time) of pulling instead of pushing on tough inclines gives my quads just enough of a rest to carry on when I start pushing again.

Pulling also moves my foot back in the shoe, which gives my toes some very welcome extra wiggle room.

marz

lotus49 wrote:

marz wrote:

There is very little momentum in the cranks when pedaling with one foot. Your pedaling pedal is not going to lift up unless you at least unweight on the uplift and if you can unweight you can pull with some power.

You seem to have miss-read the current research, none of which says it is not possible to pull with some limited power. What the research is saying is that the pro's and experienced cyclists don't (not can't) pull up when riding and when asked to try and pull up there was an overall net loss in performance. The additional injection of power from lifting the pedal resulted in either a decrease in pushing power or a faster metabolic burn rate.

You have misunderstood my posts (or perhaps I haven't expressed myself very clearly). Clearly it is possible to lift your leg and I obviously didn't mean that. What I meant is essentially what you just said in the above paragraph. No net useful power is produced as a result of pulling up and no-one does it.

Consequently the whole "pulling on the upstroke" thing is a myth. It doesn't work so no-one does it.

You are right, I miss read your last post, my bad.

And I agree that current research seems to point towards the myth of pedaling in circles.

mike6

Yea....statistics, statistics. The fact remains, If you "concentrate" on pedaling in circles you will be faster and smoother. If you only concentrate on pushing on the down stroke you will look rough, and be slower.

briantrumpet

mike6 wrote:

The fact remains, If you "concentrate" on pedaling in circles you will be faster and smoother. If you only concentrate on pushing on the down stroke you will look rough, and be slower.

I think that you might find that this 'fact' might need a little more scientific justification to get beyond being an assertion. Not that I necessarily disagree with you, but the older I get, the less I believe in 'facts'.