Model B - rebalance flywheel or get a Model D?

[jim70]

I have a Model B that I bought new in 1989 and have used it only moderately off and on. When I bought it, I felt the flywheel was wobbling or vibrating too much at higher speeds. It was replaced under warranty but the new one also vibrated, although less than the first one. So here I am some 28 years later and have a renewed interest in using the rower. The vibration is annoying and my question for the forum is twofold:

Does anyone have experience with having the flywheel rebalanced at a machine shop?
And does anyone who has moved from the B model to the current D have any regrets or comments?

NB The flywheel is tight in the bearings, it is a dynamic balance issue, not worn bearings.

[Citroen]

It's a no-brainer. Sell the old B on eBay - someone will buy it.
Buy a new model D with PM5 and start rowing in the 21st century.

[Cyclist2]

Or keep the B, play with it as desired, but get the new D as Dougie scolded.

I have a model B, 1987 version, and still row it a little, wouldn't think of getting rid of it. Most of my meters are on a mere 20th century model C on slides with an upgrade PM3. Works for me.

[Steve1960VA]

I know nothing about Model Bs, but if you think the flywheel is out of balance (sort-of hard to imagine that it's out of balance much - though C2 does add balancing weights here and there, I think), and if you're handy with hand tools, checking the balance of the flywheel might be easy enough.

I balance my motorcycle tire-wheel combos by placing the bike's wheel axle through the wheel bearings, suspending the tire-wheel combo on a couple stands, and noticing (marking) the light side of the assembly (the side that will rotate upwards to the top). A small weight of some sort is applied to the light spot, and the process is repeated until no point / side consistently goes to the top. At that point, it's balanced (or well enough - never a vibration issue).

I don't know how easily that process could be done on erg flywheels, but it should be possible with enough effort.

My guess, though, is that the flywheel's not out of balance - or not enough for you to detect it.

Anyway, if you're looking for a small project, and are otherwise happy with the Model B, and are interested in trying to save some money, this might be worth a try.

[Allan Olesen]

I balance my motorcycle tire-wheel combos by placing the bike's wheel axle through the wheel bearings, suspending the tire-wheel combo on a couple stands, and noticing (marking) the light side of the assembly (the side that will rotate upwards to the top). A small weight of some sort is applied to the light spot, and the process is repeated until no point / side consistently goes to the top. At that point, it's balanced (or well enough - never a vibration issue).

Your method can only solve static balance problems, not dynamic balance problems. The OP suspects a dynamic balance problem.