Concept2 Forum

What would be an appropriate distance away from walls using a model A? I tried to find a thread on the forum, but obviously came up short. Any assistance would be appreciated..... I did read something that mentioned 3 feet away from the side and flywheel, but I can't remember where or even if that was correct.
Thx,
Brent

I can see only two reasons to care how far away your machine is from the wall. First is for safety, but the machine shouldn't move around while you're using it (if it does you need to improve your technique) so this doesn't really matter. The second reason is that distance to walls COULD change the resistance (drag factor) you feel when you pull on the handle. There are lots of discussions about drag factor in the forum you can read, but at the end of the day all that matters is that you like the drag factor you are using. And I suspect the distance will have a minimal effect on drag factor unless it is very close, so I think you can set it up wherever it fits in your room.

The Model A does not have adjustable resistance (drag factor) knob, unlike all later machines which do have an adjustment knob. So besides distance to wall, the only adjustment for drag factor is by moving the chain between the different sprockets (like changing gears on a bicycle - see the manual). If you try the different sprocket settings and still don't like the drag factor, you could try it at different distances from your walls to see if that makes a difference.

If you update to a PM5, that should show you what the drag factor for each of the sprockets and wall distance is if you want to try to quantify it.

Thank you Jag for your response. Just as you've stated I will try various sprockets and see what feels best.

The DF on the Model A can also be changed by removing (or possibly adding?) vanes. I don't believe that the gearing affects the drag factor per se, just feel of the pull. Wall distances and stray air currents will most certainly affect it.

The DF on the Model A can also be changed by removing (or possibly adding?) vanes. I don't believe that the gearing affects the drag factor per se, just feel of the pull. Wall distances and stray air currents will most certainly affect it.
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Bob S. Marathon Poster

This is not recommended at all. There are 9 fan blades equally spaced in the spokes of the flywheel so removing one or two will impart an imbalance. If you remove every third fan (total 3) you won't have the imbalance problem, but if the resistance feels too heavy even on the large sprocket then just put the machine close to a wall.

In the early days of the Model A we hadn't come across the term "drag factor". What we were searching for was a balance of resistance (fan blades) and momentum (steel rim weight), speed and gearing to come up with a flywheel that delivered a certain feel at an economical price. There was a lot of trial and error with different combinations of these factors that lead us to the Model A bicycle flywheel. It was recognized very early on that one could get an easy ride by putting the machine close to a wall or another active erg since almost any disruption in the air flow tended to reduce the drag. We were using a simple analog revolution counter at the time so scores were only felt to be comparable at competitions where machines were spaced a minimum 6 feet apart. This issue was part of the impetus behind the development of PM1.......C2JonW