Rough pull?

[stewstar73]

I have a Model C with PM5 (my 6th machine). Just picked up a model D with PM3. The pull is slightly rough as if something needs adjusting. More of a vibration than anything but is off putting and is nowhere near as smooth as my C. Anyone suggest any obvious quick fixes. I oiled the chain

[Ombrax]

Is the roughness / vibration only during the pull, or does it continue as the flywheel spins after the stroke?

If it's the later it's possibly an unbalanced flywheel (which is probably hard to fix on your own).

[stewstar73]

Just on the pull

[Ombrax]

Sorry, I've never experienced that particular problem on either my Model C, or any of the E's I've used at the gym.

Surely someone here who's done lots of erg maintenance has come across that issue and will have some ideas for you.

[stewstar73]

Gunky chain and sprocket maybe?

[Cyclist2]

I've overhauled one Model C (same mechanism as a D). If the machine is old and/or has had a lot of use and abuse, the plastic idler pulleys can get grooved, the sprockets worn and gunked as you suggested. Those parts are pretty inexpensive from C2 and not too difficult to replace if you're handy with a few tools. C2's web site has all sorts of schematics and instructions and the parts are sold there too.

Good luck!

[Allan Olesen]

I think I know what you mean by "rough pull". I have experienced the same with my D after replacing chain, sprocket and pulleys. I got the advice to inspect for stiff chain links, which apparently is a problem with some batches of C2 chains.

To be honest, I never got around to doing that inspection, but I started using a thinner oil for chain lubrication, and it solved most of the problem for me.