Flywheel wobbling/shaking

[Jbaggy]

Hi guys,

Just got myself a Model C- I’m new to rowing machines so please bare with me. The flywheel shakes once I start rowing, causing the whole machine to vibrate. I’ve opened it up and given the flywheel a clean, the balancing weights look like they haven’t been touched either. There is also very little play when I move the flywheel by hand.

When rowing I can see the flywheel shaking, and I can see one edge of the flywheel pulls further out, does anyone have an idea as to what this could be caused by? Unfortunately it won’t let me attach a video.

Thanks

[Carl Watts]

Its thrown a weight off the flywheel at some point and someone probably just threw it away.

It only needs one missing and its going to vibrate badly, especially while your in the recovery phase and its slowing down from the peak rpms.

You said there is no play so as long as the bearings are okay. The flywheels do not run perfectly true so you may see a wobble in the outside of the black nylon edge of the blades. This is normal but the balancing is critical. I could not believe the difference just one weight missing and it only weighed like 1.5 grams. In the end I drilled and tapped holes in the steel and replaced all the weights on the inside edge of the blades with button head cap screws. The screw filled the hole and the "Head" of the screw weighed the same as the weight. I now only have one weight on mine on the outside edge and its marked on the blade with a bit of white paint the position of it should it ever come off.

[froque]

I suggest buying a new flywheel. Flywheels are expensive so do your research first.

If you can, you could try another flywheel to confirm that indeed the flywheel is out of balance ( from a friend or from your rowing club), they are pretty easy to swap.

I have tried to balance flywheels, but I have never been happy with the results, and eventually I have replaced them.

Make sure you mark with permanent marker the weights in the plastic blades of a new flywheel, those fall off especially when you are cleaning.

Cheers

[Carl Watts]

Yes they are very difficult if not impossible to re-balance using only the rower.

I put up a post a while ago recommending that everyone with a new rower take the 10 minutes it takes to mark the position of the flywheel weights and preferably ID it as if you look closely you will notice they have different thicknesses and hence look the same but the weights are different.

Failure to do this means your pretty much up for a new flywheel if one falls off.

[johnlvs2run]

I used to balance my bicycle tires with copper wire, a trick learned from a retired motorcycle racer who did the same thing with his bicycles. I simply turned my bicycles upside down on the garage floor, and spun the wheels around slowly. As the wheels sped up, slowed down and always stopped the same place, marking with tape made it very easy to see where to wrap the wires on particular spokes. Once balanced, the wheels would spin around with no deviations. Although this made the riding quite smooth, I never saw nor heard of anyone else doing this. I wonder if something similar could be done with fan cage flywheels to see where a balance would be needed.

[froque]

I used to balance my bicycle tires with copper wire, a trick learned from a retired motorcycle racer who did the same thing with his bicycles. I simply turned my bicycles upside down on the garage floor, and spun the wheels around slowly. As the wheels sped up, slowed down and always stopped the same place, marking with tape made it very easy to see where to wrap the wires on particular spokes. Once balanced, the wheels would spin around with no deviations. Although this made the riding quite smooth, I never saw nor heard of anyone else doing this. I wonder if something similar could be done with fan cage flywheels to see where a balance would be needed.

The flywheels can be balanced using similar method but will never be like balanced from factory.

When I have tried to balance using similar method, for example, at 2:00 pace they seem Ok, at 1:45 there is small noticeable imbalance and at 1:30 the rower starts to shake too much for my liking. Perhaps it is me not been very good at balancing, but I can tell that without specialized equipment you cannot fine balance the flywheel.

And by the way I have used lead tape (sold for golf clubs weights), the same lead tape strips work perfect for balancing bicycle wheels

[johnlvs2run]

by the way I have used lead tape (sold for golf clubs weights), the same lead tape strips work perfect for balancing bicycle wheels

Awesome.

[Carl Watts]

Balancing the flywheel is a bit more involved.

Like you car wheels if you have ever taken the time to look they can have weights on the inside and the outside edge due to the width of the wheel.

You C2 flywheel will have weights in the inner edge of the nylon blades and sometimes on the outside edge as well.

I suspect your C2 flywheel is doing more rpms than your bike wheels are as well and also its pretty heavy. All factors combined means I think you will find its balanced by Concept 2 to a very tight tolerance.

Probably not a good idea to try and compare the balance of your bicycle wheels (something I never found I needed to ever do) and that of the Concept 2 flywheel. Like I said before, you loose just one weight and you instantly know you have a problem.