Model B Best of the Best

[700t]

Earlier this year I bought a model D (hardly used) for a great price. This is a great machine and is used by
myself and my wife. Now my gym has 2 Model B rowers and I find myself preferring the model B to
my D at home. I love the sound, the air blowing in my face and best of all I find it easier to pull lower splits
on the model B. I can pull 1:47- 1:49 splits continually for 20-25 min on the B model but at home I can't seem to get below 1:50 for long pieces. Feel free to comment. thanks

[TabbRows]

As an erger on both a Model B (at home) and D(at the gym), my first guess is to check your drag factors. You should strive to get similar drag factors on both machines. Aim for 120-130 range. Maybe a little less for your wife (110-120). Some heavy weights on these boards go up to 150. A slightly heavier drag with similar effort/technique, can produce a slightly faster erg time for the same spm. Make sure the fan and grill cover in you D at home is clean and the chain is oiled. If the Bs at the gym have speed rings, the chain should be on the smallest (outside) cog and the speed ring opened about a 1/2 inch or so. You may have to play with this a bit. Next check the location of your D at home nad the B's at the gym. If either are near a wall or a corner, you'll get a different drag factor than out in the open. If you're getting a lot of breeze on the Bs it sounds like they may be against a wall and blowing the air back to you. Get a C-Breeze for your D at home to get the same cooling effect. If the B's in the gym seem "easier" to row (lower drag factor, inside larger cog), then you may be also erging at a faster rating, that also will reduce your splits a bit. With drag factors adjusted and erging at similar ratings, you should find your splits fairly consistent between machines. And welcome to the B fan club!

[700t]

Thanks for the reply, on the B model there is no speed ring, I row with the 15 sprocket and the vents closed,
do you know what that would equal on my D model(DF) ?I'm not close to any walls and I took my cover off and cleaned all
around on my D. Also I wonder if the flywheels are a different weight between the 2 models and would explain the different feel?
I also notice the PM1 reacts quicker to changing pace than the PM3. anyone else notice that? thanks

[TabbRows]

I also notice the PM1 reacts quicker to changing pace than the PM3. anyone else notice that? thanks

Ah! That explains all your differences. A PM1 can't display drag factor. And as I recall, there are some subtle calculation differences as well. Plus you need to be on the smaller 13T cog, with proper setting that'll be much more comparible to the D at home..

There's a comparison chart on the Concept 2 site under Service>manual, schematics that'll help you make a good comparison for the settings between how you are set up on your D and how to set up the B at the gym.

[Leo Young]

I find myself preferring the model B to my D ..... I find it easier to pull lower splits
on the model B. I can pull 1:47- 1:49 splits continually for 20-25 min on the B model but at home I can't seem to get below 1:50 for long pieces. Feel free to comment. thanks

One of the reasons you fell like you can pull lower splits on the B, is because the pace/500m displayed on the B is a truncated score, whilst the the C,D & E displays a rounded pace/500m. So 1:49.9/500m pace displays on the B as 1:49 and on the D as 1:50. Despite that the actual scores achieved in terms of time or distance for a set piece are calculated exactly the same. The watts score or the B however is calculated using a far more complex and and accurate formula that takes into account the rate of acceleration.

Secondly, the model B is geared higher than the model D. On the B the small 13 tooth cog with the vent 1/2 open is approximately the same drag as vent setting 10 on the D and the vent closed approximates 8. On the large 15 tooth cog, open approximates 6.5, 1/2 open is similar to 5 and closed matches about 3.5. With the speed ring and large cog, open approximates 5.5, 1/2 open about 3.5 and closed about 2.

[700t]

Anyone have the number of Model B rowers produced during its 1986-1993 production by Concept2?

[luckylindy]

Anyone have the number of Model B rowers produced during its 1986-1993 production by Concept2?

73

[Slidewinder]

700t wrote, " Also I wonder if the flywheels are a different weight between the 2 models and would explain the different feel?"

The Model B and the Model D flywheels are very different in weight and design. I own a Model D and two Model B's (which I've cannibalized for my mechanical projects). The Model B flywheel is a heavy aluminum casting with straight radial fins. The Model D flywheel is a light weight plastic squirrel-cage design. I don't think any amount of tweaking could render them identical in "feel". By virtue of the greater mass of the Model B flywheel, there will be a larger inertial component to the resistance on the old machine. The Model D flywheel being lighter, has less inertial resistance, but the vaned squirrel-cage design would be moving a greater volume of air, creating higher air resistance on the Model D.

Is one "better" than the other? My (untested) hypothesis is: the higher inertial resistance of the Model B flywheel would more accurately replicate the inertia of a rowing shell at speed. If true, then rowing replication fidelity has been partially sacrificed for the sake of lower manufacturing and shipping costs.

[700t]

To me it seems the D flywheel is heavier than the B. Even though the D has lightweight plastic fins, the wheel is made from steel as compared to the aluminum on the B. Another variable might be that I always use the 15 sprocket on the B
as compared to the 14 sprocket on the D. In my opinion I think Concept2 should have contiued with the 2 sprocket options for vthe D model. I find the B model a better workout and I can achieve lower splits for some reason and I'm still trying to analyse the difference.

[Bob S.]

To me it seems the D flywheel is heavier than the B. Even though the D has lightweight plastic fins, the wheel is made from steel as compared to the aluminum on the B. Another variable might be that I always use the 15 sprocket on the B
as compared to the 14 sprocket on the D. In my opinion I think Concept2 should have contiued with the 2 sprocket options for vthe D model. I find the B model a better workout and I can achieve lower splits for some reason and I'm still trying to analyse the difference.

The C, D, and E all have more effective damping than the B, so the extra gearing is not needed to give a wide drag factor range. The drag factor should be major effect on the feel of the machine. If the drag factors are the same, the machines should feel the same. The major problem with the B is that most of them have the original PM, which doesn't show the drag factor, so you can't tell where you are. This can be taken care of by equipping a B with a PM 3 or 4 (or, I suppose, with a PM2+).

Bob S.

[Slidewinder]

One of the Model B flywheels is sitting loose in my shop. I weighed it a few moments ago with a spring fish scale - not accurate, but that flywheel is close to twenty pounds. It's a substantial hunk of metal. I am confident in asserting that it is much heavier than the Model D flywheel. Of course, the weight of something is not arguable. It's a matter of fact, not a matter of opinion. Jon Williams at Concept 2 could positively answer this question.

[Carl Watts]

The PM2, PM2+ and PM3/4 all display the drag factor.

There is something wrong if you cannot acheive better times on the Model D, especially for the 500M as it is ergonomically a better rower and far smoother at higher ratings.

The Model D/E is the best rower made by C2.

[Slidewinder]

Curious about this flywheel weight question (and not meeting with the duchess and her entourage until later in the day), I removed the flywheel from my Model D and weighed it. By my cheap spring fish scale it weighs 12-13 pounds, as does the Model B flywheel (earlier posting included some attached bits and pieces that weighed more than I thought). So we both guessed incorrectly.

My curiousity is not so great however, that I will re-assemble my Model B to experience the difference between it and the Model D, which I'm sure exists. It's not just a matter of more effecive damping on the Model D. The vanes on the flywheel are a different design, which is going to contribute to a different "feel".

[c2jonw]

The model B flywheel is a single piece of cast aluminum incorporating momentum, resistance and bearing hub into one hunk- a great idea at its inception but over time the price of aluminum increased and led us to the model C design flywheel which has worked well through production of the C, D, E, SkiErg and now the Dynamic erg. This flywheel uses a 1/8" thick, 17" diameter steel disc as the momentum component, a custom design injection molded fan for the (air) resistance and a steel hub for the bearing and axle interface. The weights of a B vs C/D/E flywheel are all about 8-9 pounds, though it's not the weight that matters, but rather the moment of inertia, which is determined by the weight and it's distribution about the center of rotation. A 1 pound flywheel can have a higher MOI than a 2 pound flywheel if it's weight is distrubuted further from the axle. MOI is checked and adjusted on every flywheel to achieve comparability between machines of +/- 1/3 of one percent. I think the main reason for the difference in feel is the sprocket size and different drag factors. Check out the chart at: http://www.concept2.com/us/support/manu ... arison.pdf
C2JonW

[Bob S.]

Check out the chart at: http://www.concept2.com/us/support/manu ... arison.pdf
C2JonW

Jon,

That chart shows 10 damper settings for the D/E, numbered 1 - 10, but there are actually 11 different points on the scale. In the mostly (but not completely) closed position, the lever is at a zero point of the scale. There is space below the #1 on the scale and above the #10, so when the damper is open all the way, the lever is above the 10. C2 seems to have gone out of its way to make the scale difficult to read. With the aid of a flashlight shining at the right angle, I was able to see that the numbers have an alternating character. The odd numbers are smooth and set in a slightly raised, rippled area of the plastic cover. The even numbers are raised and rippled in a smooth area of the plastic cover. With a felt tip pen, I have marked my own Model D at the top of each of the (approximately 1 1/8') blocks of alternating smooth and rippled plastic. The lowest mark is at the end of the range of movement of the lever and I consider that to be zero. The highest mark, at the other end of the range of the movement of the lever is what I would call 10. It is at the top of the smooth area that has the raised an rippled figure 10. Each of the other marks are at the dividing lines between the alternating blocks of differently finished plastic. I consider the top of the block containing the number to be the proper number setting for the lever. If one uses the center of a number for the lever setting as a guide, it leaves half block gaps at each end of the scale that would imply a range of settings from 0.5 - 10.5.

Sorry for the wordy mess of that first paragraph. I find it hard to find the proper words to describe the situation. Almost as hard as it is to read that blooming scale on the plastic cover.

Do you have any comment? I would like to know what C2's take is on this issue (these issues?). It is a great machine. Why did they make the numbers so hard to read and why is there this ambiguity of the settings?

Regards,

Bob Spenger