Model C Chain Idler Axle and Pulley

Maintenance, accessories, operation. Anything to do with making your erg work.
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GreenGiant
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Model C Chain Idler Axle and Pulley

Post by GreenGiant » January 18th, 2025, 5:07 pm

I have an old Model C rower. I bought a Drive Chain Assembly kit to replace the two pulleys, axle, sprocket, and everything else in the kit.

I remove everything up until the Chain Idler Axle and Pulley. It requires a T-27 driver to remove the second Hex screw. I screw in the T-27 spacer screw, and remove the second Hex screw. Now I am not able to remove the T-27 screw as the chain idler axle just spins.... I need to remove the Chain Idler Axle with spacers in order to replace the old Pulley. I am also finding it difficult to remove the Flywheel axle assembly with the recommended adjustable wrench and 9/16" wrench.

It rows rough, so I am hoping replacing all of this will help.

Any suggestions are very much appreciated, TIA.

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Carl Watts
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Re: Model C Chain Idler Axle and Pulley

Post by Carl Watts » January 18th, 2025, 9:16 pm

There is a trick to those pully screws.

Once you get one out you need to replace it with a longer screw with a nut on it. Screw it in and do up the nut and then remove the hard to get out screw.

Slacken off the nut and remove the longer screw. Thread is 3/16" UNC from memory.

You need two 9/16 wrenches or spanners in combination with just holding the flywheel and letting the one way bearing in it from stopping the shaft turning.

Make sure you put a drop size bit of a thin grease on the flywheel one way roller bearing before running it on the new shaft.
Carl Watts.
Age:56 Weight: 108kg Height:183cm
Concept 2 Monitor Service Technician & indoor rower.
http://log.concept2.com/profile/863525/log

alanmushnick
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Re: Model C Chain Idler Axle and Pulley

Post by alanmushnick » February 23rd, 2025, 1:52 pm

I have a model C also. Are there any photos of this. I don't exactly understand what Carl Watts is trying to explain
Alan

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Ombrax
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Re: Model C Chain Idler Axle and Pulley

Post by Ombrax » February 24th, 2025, 12:32 am

GreenGiant wrote:
January 18th, 2025, 5:07 pm
Any suggestions are very much appreciated, TIA.
1) Did you check the C2 web site? (see link below) They have lots of helpful information.
https://www.concept2.com/support/indoor ... leshooting

2) If all else fails, give them a call (or send an email) - they've always been super-helpful when I've reached out. See the second paragraph at the link above for contact info.

Good Luck

Edit: have you read this?

https://cms.concept2.com/sites/default/ ... cement.pdf

Cyclist2
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Re: Model C Chain Idler Axle and Pulley

Post by Cyclist2 » February 24th, 2025, 2:09 pm

alanmushnick wrote:
February 23rd, 2025, 1:52 pm
I have a model C also. Are there any photos of this. I don't exactly understand what Carl Watts is trying to explain
Alan
I had the same problem a few years ago, Carl explained it to me then, so I understand it now. I don't have photos but I'll try to clarify the method.

Imagine you have a rod with a bolt threaded in each end. One bolt will be tighter than the other, so when you put a wrench (spanner) on each bolt to loosen them, only one will come out. Take the removed bolt and thread a nut onto it, then reinsert it into the rod (if the bolt is too short, use a longer bolt, as Carl says). Once that bolt/nut is reinserted, take your two wrenches and tighten the NUT down against the rod. Now that side will be tighter than the other so the other bolt will come out. Now take your two wrenches, loosen the nut and that bolt/nut combination will unscrew easily from the end of the rod.

Hope that helps. I got two destroyed Model Cs put back into one functional one, still using it. Have fun!
Mark Underwood. Rower first, cyclist too.

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