Physics and biophysics of the Dynamic Indoor Rower

[floatingbones]

I just viewed Dick and Peter's video of the Dynamic Rower. I was going a bit crazy trying to figure out how the device could work without the footrest being connected to the power train. I now understand how that connection works!

I liked the cutaways to the Model E on the ground and mounted on sliders. It would be cool to cut a video showing the three different machine options in panels on top of each other. Footage with the same rower pulling at synchronized cadence would be good: about 45 seconds at full speed and then about 30 seconds in slow-motion.

This would make an interesting lesson for a high-school physics course: what impact do the different frames of reference have on the amount of work being done? Students could attempt to explain any difference or to explain why the amount of work should be identical or very close. This is a sterling example of frames of reference, and I don't think that students get enough real-world examples of that concept.

I believe this machine would be attractive for Pilates studios. Since both the seat and the footrest move, there is an added component of balance/stabilization not present in the standard D or E models. Most aerobic machine strive for a stable nonmoving base; this machine has all three points of contact moving relative to each other. That is similar to the Pilates philosophy on the Pilates Reformer: the base platform slides and is linked with a line of tension to the hand/foot straps. On both machines, the forces must be balanced. Studios would also be happy with the smaller footprint of this machine.

[tarverator]

Can you link the video, please? I have the same question: how is the footrest connected?

[Citroen]

There's a video here: http://www.concept2.com/indoor-rowers/dynamic

[tarverator]

Thanks, but the official video doesn't answer my question, which seeing the Dynamic up close would probably answer at a glance: what is the linkage (there must be one!) which connects the footrests to the flywheel? Is it built in to the bottom rail? So, are there two cords going to the flywheel, one from the handles and one from the footrests? That's what I really want to know.

[Bob S.]

Thanks, but the official video doesn't answer my question, which seeing the Dynamic up close would probably answer at a glance: what is the linkage (there must be one!) which connects the footrests to the flywheel? Is it built in to the bottom rail? So, are there two cords going to the flywheel, one from the handles and one from the footrests? That's what I really want to know.

The flywheel is pulled by a chain connected to the stretcher (aka footboard).

Bob S.

[tarverator]

OK, so the stretcher acts essentially just like the handle of the static (with appropriate gearing), connected by a chain running inside the lower rail. Got it.

Then what about the cord from the handle? Does it also connect to the flywheel through it's own linkage, with the cord running alongside the chain? Or does the cord loop around the stretcher somehow with pulleys or something? Or does it just simply attach directly to the stretcher?

There are lots of parts diagrams of the static ergs, but I can't find one of the Dynamic that shows the power train, the basic geometry of what pulls what. Like I said, I am sure the answer to my question would be dead obvious if I could have even 5 seconds with a Dynamic in person.

[OarConsequences]

Try checking out the schematics.

http://www.concept2.com/service/manuals#dynamic

[tarverator]

Thanks!