No resistance just after Catch.

[GeoffreyDuP.]

I have just obtained a Model-D indoorrower and i noticed that the resistance is not right there from the Catch.
Only at around 1/10-th in the Drive, i feel the resistance picking up.
As i am used to rowing on water (where the resistance is instantly there at the Catch) this feels very unnatural and also causes an upsway of my back in the first phase of the drive.

Is there anything that i can adjust on my Model-D (or PM-5) so that it mimics more the real rowing feeling; instant resistance, right after the Catch?

Thanks in advance for anyone responding or recognising this,
GeoffreyDuP.

[Citroen]

If it's a second hand machine you probably need to replace the shock cords.

If it's a new machine (or one with low mileage) then try opening the damper a bit. Get the drag factor higher (120-130 or more) and look at your rowing technique.

[Bob S.]

Using the C2 slides helps to some extent.

Bob S.

[Carl Watts]

The effect of the one way bearing in the flywheel is that the sprocket with the chain on it doesn't begin to drive the flywheel until the rpm of the sprocket exceeds that of the flywheel.

So if the drag factor is too low with high stroke rate or spm the flywheel is still spinning very fast so there will be an increased dead zone at the start of the drive.

Make sure the cage for the flywheel/fan is clean, check this with the damper at 10 and look at the drag factor on the monitor, you should get 280 or there abouts.

The other problem that can occur is if the one way bearing is stuffed it is not locking up and is slipping on the shaft

[jackarabit]

Carl writes:

The effect of the one way bearing in the flywheel is that the sprocket with the chain on it doesn't begin to drive the flywheel until the rpm of the sprocket exceeds that of the flywheel.

The most succinct and accurate description of this phenomenon that I have ever seen on this board, certainly including several awkward attempts by yours truly! Anyone beginning to consider optimizing their erg stroke should consider all the implications of this window of temporal opportunity hidden in the deceleration of the flywheel. Jack

[GeoffreyDuP.]

Thanks to you all replying and in particular to Carl. His description of the inner workings of the drivesprocket and flywheel perfectly makes sense.
I now also understand how increasing the dampersetting would make the flywheel decellerate quicker during the recover, thus shortening the dead zone at the start of the drive. This would however also increase the overall resistance during the drive. I choose not to do that as i am having trouble enough keeping my heartrate down when rowing at an acceptable strokerate
It would set an interesting engineering challange to remedy this phenomenon...

[Bob S.]

It would set an interesting engineering challange to remedy this phenomenon...

C2 has already done it by making the dynamic model. There is probably some lag, but I can't detect it. When I use a grounded model D for time trial, the first stroke comes as a surprise. There is much less feel of resistance than I get on my dynamic.

Bob S.

[InlineJinn]

The effect of the one way bearing in the flywheel is that the sprocket with the chain on it doesn't begin to drive the flywheel until the rpm of the sprocket exceeds that of the flywheel.

Oh, so that's how it works. I have been wondering. I've been going onto my toes before the catch so that I'm not pulling hard for that slack interval, and then increasing the drive once I feel the resistance. I'll try experimenting with the damper too, but since I'm not strong (my ranked times are always close to, if not at, the very bottom) I really feel it when I increase the damping.

Thanks,
John B.

[Cyclist2]

This would however also increase the overall resistance during the drive. I choose not to do that as i am having trouble enough keeping my heartrate down when rowing at an acceptable strokerate

It just changes the feel of the stroke. YOU set the level of your workout by how hard you make the drive. If you want to decrease the slack time, then increasing the drag factor works, as mentioned. Just don't put as much effort into the drive and you can keep your heart rate where you want it. Your stroke rate will be slower than at a lower drag factor, but ultimately you are the controlling factor in how hard you work, the damper just affects how it feels (like changing gears on a bicycle).

[hjs]

This would however also increase the overall resistance during the drive. I choose not to do that as i am having trouble enough keeping my heartrate down when rowing at an acceptable strokerate

It just changes the feel of the stroke. YOU set the level of your workout by how hard you make the drive. If you want to decrease the slack time, then increasing the drag factor works, as mentioned. Just don't put as much effort into the drive and you can keep your heart rate where you want it. Your stroke rate will be slower than at a lower drag factor, but ultimately you are the controlling factor in how hard you work, the damper just affects how it feels (like changing gears on a bicycle).

Proberly better to work the other way. Lower the drag, that way you are forced to drive faster. If you after a while go back to a normal drag, your stroke will be a lot better. Using a high drag for normal rowing only makes your stroke more lazy and slow.

[Cyclist2]

True, for general rowing proficiency. The OP was about the slack at the catch, and my reply was based on that. I don't like real high drag, but it does slow the wheel down and reduces the slack until the sprocket catches up with the wheel. I think that after a while, you just get used to that brief slack spot and set the drag where it's comfortable for you, or set it to match that day's workout plan, or whatever.

Whatever drag factor you use, the level of effort is determined by the rower, not the machine.

[Carl Watts]

Its a compromise, more drag and a slower rating equals less of the resistance at the catch problem.

Its all very well to say increase your legspeed at the catch to quickly get the one way bearing to engage but it depends on you physically being able to do that.

There are also other things to consider like your height and weight, if your really short then with your reduced travel on the slide you really don't want a big dead zone but if your really heavy then getting the speed is also going to be a problem. If your really tall then you clearly have a massive advantage, the advantage appears to be disproportionate and those extra few inches make a huge difference.

have to admit I have developed a bit of a problem due to all training and fitness and no racing as all my rowing is now at sub 20 SPM and my body no longer likes racing up and down the slide, probably because I'm too heavy to keep it up for a longer row.

The one way/clutch bearing also needs lubrication now and again to help extend its life. Well maintained and you shouldn't have to replace it. To avoid the confusion because "Clutch" and "Grease" do not appear to go well together the needle bearing actually performs its function by a cam in the rollers and leaf springs for it to lock up and the grease has no effect on it "Slipping", quite the opposite no grease and the rollers can bind up and fail to grab the sprocket shaft.