Concept2 Forum

I'll be moving into a condo shortly and plan on taking my Model D with me.

I like my sprints. I like making that Erg as loud as possible. However, I'm not sure my neighbors will enjoy it

I remember seeing a cover of sorts a few years ago that reduced the noise. It covered just the wheel if I remember correctly.

Does anyone know where I can find it? Or does anyone know how to reduce the noise?

You are probably thinking of the "C Breeze", which is primarily designed to cool the user , I dont know if it has any noise reduction side effects..

http://www.ps-sport.net/

The model D doesn't make much noise, so it shouldn't be any problem.

If you're on the 2nd floor then maybe put a rubber pad underneath, or get some rubber from an old truck tire innertube and put that under the feet.

I've covered the fan cage of the model B with black roofing paper, and then with rubber from an old truck tire innertube and either of those reduced the noise quite a bit.

John,

It's off topic, but I saw your signature,
and there was this 'my weblog'!
I clicked!!

What do I get:

You are not allowed to access this Diary.

Is it just YOUR weblog, or can I/We read the log?

Awesome stuff, thanks guys!

Yeah, the c-breeze was what I was thinking of.

I guess when I move in I'll find out how thin my walls are

Hi Tyn,

You are certainly welcome to access my diary.

Try again.

John,

When you cover the fan cage on your Model B, did that affect the drag factor settings?

For the most part, I reduce the noise by taking out my "ears"...
Quiet enough for me but probably not anyone else.

With no hearing aids on, I can't hear the Model D at the club it at all, but can still hear the Model C, albeit not as loud as the Model B at home.

ST

TabbRows wrote:John,

When you cover the fan cage on your Model B, did that affect the drag factor settings?

I can't speak for John, obviously, but I did some of my own experimenting with a cover on my old model B. With the original PM(1), there was no way of knowing the drag factor and I had no idea that there was such a thing. Then I acquired and installed a PM3 and gradually found out what it was all about. With the damper of the Model B fully closed, I was getting a draq factor of over 150 and that was at high altitude, so the DF would be even higher with the higher density of air at lower elevations. Since I was using a 15 cog gear, instead of the 14 cog gears of the later models, it would be like having a DF of about 140+ on a C or D. I also had the option of using a 13 cog gear, but that would make it feel like a much higher DF. I found a convenient cardboard box that neatly fit over the wheel, effectively covering it except for a narrow opening on the back end (i.e. the end where the monitor, support, and chain are). This reduced the drag factor by a full hundred points. I was getting readings in the low 50s. I never did work out with the covered wheel. I had been using it uncovered, damper set in the middle, on the 15 cog gear, mostly at sea level for about ten years. I was used to it and saw no need to change except to close the damper down. A few months later I bought a Model D and decided to get used to using it at a more conventional DF, under 140. Currently, I leave the damper at 6, which gives me a DF of 115-125 depending on local temperature and pressure.

Bob S.

TabbRows wrote:John,

When you cover the fan cage on your Model B, did that affect the drag factor settings?

Yes, definitely. Most of the reduction is due to the speed ring on the side though, then the perimeter covering just reduces it a bit more. My model B has a drag factor range of 65 to 200, with a model C 14 tooth cog. I changed to a 14 tooth cog soon after getting a pm2+.

However, you can compare the resistance from a model B 15 tooth to that of a model C 14 tooth cog by dividing the reading by the difference of the cubes of the number of teeth on the cogwheels.

The formula is:
[15 tooth df] x [14x14x14] / [15x15x15] = 150 / 1.23 = [model C df] = 122

This is a formula that I came up with a few years ago, then decided just changing the cogwheel was easier.

Thanks John and Bob. I take it that had my wheel been fully covered to block out the wind last week, my effort in the 1/2 marathon might have pulled a slightly better time. I've noticed that when I do intervals at home and the the next sessionof intervals on the club's Model D, I have to back off a bit at the club because it seems like I'm pulling at a high wattage than at home for what has been comparable drag factor read outs on both machines. But it's not the case in reality.

Anyway, we're drrifting a bit off topic so I'll stop here.

ST

If you're using the small 13 tooth cogwheel on the model B and are getting, for example, a drag factor of 120, this is the equivalent resistance of a 150 df on a model C or D.

120 B13 / [13x13x13] x [14x14x14] = 120 / .80 = 150 C14

If the df at the gym is 120 on a 14 tooth model C, then the equivalent resistance with using a model B 13 tooth cogwheel would be a drag factor of 96.

120 C14 x [13x13x13] / [14x14x14] = 120 x .80 = 96 B13

If you're using the small 13 tooth cogwheel on the model B and are getting, for example, a drag factor of 120, this is the equivalent resistance of a 150 df on a model C or D.

Well that certianly explains why I was having problems maintaining a 1:52 AN effort on a 5x2' workout on Monday at home (lack of time for more) but was swinging over 300 watts average (1:44/500!?) at the club last night on the same workout but up 2 beats in rating. Both drags were 115. By your formula, I was pulling 144 on the B but 92 on the C.

TabbRows wrote:

If you're using the small 13 tooth cogwheel on the model B and are getting, for example, a drag factor of 120, this is the equivalent resistance of a 150 df on a model C or D.

Well that certianly explains why I was having problems maintaining a 1:52 AN effort on a 5x2' workout on Monday at home (lack of time for more) but was swinging over 300 watts average (1:44/500!?) at the club last night on the same workout but up 2 beats in rating. Both drags were 115. By your formula, I was pulling 144 on the B but 92 on the C.

There is no need to do any conversion from the C reading of 115. The more significant difference is the +2 in rating. (about an 8 second swing at the paces involved).

TabbRows wrote:Well that certianly explains why I was having problems maintaining a 1:52 AN effort on a 5x2' workout on Monday at home (lack of time for more) but was swinging over 300 watts average (1:44/500!?) at the club last night on the same workout but up 2 beats in rating. Both drags were 115.

Right, 115 with the B on 13 is equivalent resistance to 144 on a C.

To have the same resistance as a C at 115 drag factor, put the B/13 on a drag factor of 92.

You can lower the drag factor by covering the fan side of the erg, which can be done in various ways.