Model D - too much resistance?

[johnlvs2run]

I got a slightly used 2015 Model D last August, used it for a few months, then gave up and was planning to sell it but have been giving it another chance this past month. The issue is that it seems to have too much resistance, & slower paces, compared to my previous use of model BCD rowing machines, and it's at least 10 seconds slower than my current pace on the Bikeerg.

If there's a glitch in the machine, then I'd like to resolve it.
I have kept the chain lubed with sewing machine oil since getting it last August.

Most of the resistance feels like it's coming from the sprockets and they make a lot of noise, much more than the flywheel. When I stand beside the housing and pull the chain very slowly just a couple of inches, the sprockets make a loud clack-clack-clack-clack noise. This makes me feel the sprockets are causing a problem, since the shock cords are not involved at that speed. However maybe there's an issue with them too.

If possible, let me know your suggestions of possibilities and what to look for when checking inside.

[Ombrax]

What DF do you get for various positions of the damping lever?

How does that compare to other rowers you've used on the past?

[johnlvs2run]

The machine is clean and well taken care of.

The drag factor range is 80 to 220 and I'm using 130 (position #5).

This range compares well to the rowing machines that I've used in the past.

[jamesg]

Have you checked the one-way bearing? To make that noise it would have to be completely dry, so maybe the grease was replaced with oil, which is easier to apply.

My C is about 15+ years old too. When cold at times it failed to engage, so a year ago I took the flywheel off and doused the bearings with oil before refitting. No prob since, at least down to about 15C (60F).

I also got a complete new flywheel, so now I have a spare.

130 df is too high for me too, so I use 90-95. I have a filter over the damper, so the fan stays clean for years, with constant drag factor. Even at low force (350N) the pull time is short, so I get plenty of rest time before the next one.

[johnlvs2run]

Have you checked the one-way bearing? To make that noise it would have to be completely dry

Thank you for that suggestion. I will check the bearing asap and hope it hasn't been damaged.

[Tsnor]

When I stand beside the housing and pull the chain very slowly just a couple of inches, the sprockets make a loud clack-clack-clack-clack noise.

There is a plastic cover on the bottom of the chain path. This slides in, and is easy to dislodge if something presses up on the bottom of the chain path. The plastic cover will make that sound if it is push up inside the chain path as each chain link hits the plastic.

Look at any of the youtube videos for replacing chain on model D. (e.g. https://www.youtube.com/watch?v=kA-rW268Ils ) They will show splitting the unit and then removing/installing this cover. Follow those steps to see what your chain is hitting. If its not your plastic cover hitting the chain then it will be something that fell inside the chain path.

Assume the sound is coming from the chain path area and *NOT* coming from the flywheel housing. If there is a chance the sound is from the flywheel use the instructions for cleaning the flywheel to get inside and check for debris.

EDIT: there is also a chain guide, part 1003 in this diagram, that can get loose and hit the chain. Assume you would have seen that right away. https://www.concept2.com/files/pdf/us/i ... cParts.pdf

[johnlvs2run]

Look at any of the youtube videos for replacing chain on model D. They will show splitting the unit and then removing/installing this cover. Follow those steps to see what your chain is hitting. If its not your plastic cover hitting the chain then it will be something that fell inside the chain path.

Tsnor, thank you for sharing your ideas.

I removed the flywheel this morning.
The clutch had plenty of lube on it, so that appears to not be the issue.
I will follow the instructions above to check inside, hopefully tomorrow, and find out what is causing the problem.

[johnlvs2run]

I finally took the erg apart again and looked inside the housing this morning.
The axle looks quite clean and shows no evidence of corrosion, so I presume it is fine.

It was hard to tell, but the shock cords both appear to be moving as they should.
The shock cord on the left front / upside down is slightly worn, apparently from rubbing on the plastic cover.
Both of the closest shock cord pulleys also showed some evidence of rubbing on the plastic cover.

Most notably, the idler and traveling pulleys keep sticking when the cords are pulled.
They move a little and then stick, have to pull harder, then stick again, repeating this over and over.
There are various videos on Youtube showing this issue, and how to replace them, but why do they fail?

This was a hardly used machine when I got it last August, with right around 10 km of use in 8 years.
Since then I've put in about a million meters in 6 months of use, hardly enough to cause pulleys to go bad.
Thus, instead of replacing them with similar poorly designed pulleys, I would rather get pulleys of higher quality.

If anyone has experience with this issue, please let me know.

[johnlvs2run]

I measured the shock cord half way through the stroke distance with a kit-chen scale just now.
The result was about 6 pounds of force, which compares to about 2 pounds of force for previous results reported on here.

[Tsnor]

I measured the shock cord half way through the stroke distance with a kit-chen scale just now.
The result was about 6 pounds of force, which compares to about 2 pounds of force for previous results reported on here.

Suggest following:

Shock cord and pullies are really cheap parts. Price them direct from C2. Then order everything you suspect is bad and replace. C2 parts are very high quality. We have 2 dozen of these ergs and help maintain a bunch of high school ergs, and pullies don't fail - so if yours failed then the replacement parts won't.

Do a post mortem on your old shock cord compared to the new one. Compare the feel of the old pullies to the new ones. Look for stuff like pieces of a failed shock cord caught in the pully. Even if the new and old cord and the pullies feel identical, at the part cost you've just bought some really cheap peace of mind, and the post mortem should give you some closure.

Also, take a look at your chain. Make sure it has the brass bushing near the handle. IF the chain is the older non-plated chain then make sure that it has no corrosion. The rust fails show up in the 2-3 feet near the handle, and for a lightly used erg depend more on how the erg was stored then anything else since the last few feet are exposed. If you see anything suspect then add on a new plated chain to your part order and install while you have the erg opened up. The new plated chain will last forever. IF chain is fine then oil it when you have the erg open, you can get all the links.

[johnlvs2run]

Tsnor, then you again for your helpful suggestions.

I took the chain off the idler pulley, and the pulley spun around freely, no problem at all.
Thus I've not been able to identify any extra source of resistance, nor the source of the clicking.

Perhaps the rowing machines are just not suitable for my type of anatomy. For that reason, and also because
it doesn't fit in well with my walking & running based exercise objectives, I have listed it on two websites for sale.