Knocking, slipping during hard pulls Model C

[mattjunior]

Hi (first post, not a rowing expert pls forgive my terminology).

Trying to fix a problem with a Model C.

During medium to hard pulls there is a double knocking sound and sensation through the handle that something is catching or slipping.

I've replaced the chain, both idle pulleys and complete axle and sprocket (except r8 bearing that didnt come with the kit).

Altho there is some slight improvement with the general noise, the knocking is still there exactly the same.

I've eliminated footplate and monorail as I can replicate it by having someone hold the rower and pulling from standing.

Any advice welcome thanks in advance

Matt

[Slidewinder]

slipping then catching - maybe a gummed up roller clutch

[mattjunior]

Whereabouts is the clutch?

[Allan Olesen]

The clutch looks like a roller bearing in the flywheel. When you remove the flywheel from the C2, you will see two bearings which are easy to remove and one which appears fixed to the flywheel. The clutch is the one which appears fixed.

If it skips, it could be in need of lubrication. But other people on this forum know more about that than I do.

[Carl Watts]

Its in the flywheel.

You can see it clearly, its on the inside of the flywheel, you need to take the flywheel off again.

Try some oil to start with on the rollers but chances are the bearing is stuffed.

Its very difficult to replace unless you make yourself up a bearing puller on a lathe.

Concept 2 will simply sell you a whole new flywheel complete as fitting a new bearing is way beyond what an average person with limited mechanical ability can perform.

[Slidewinder]

The clutch can probably be loosened up with some light oil, but shine a light in there and make sure none of the little rollers are missing - it's possible, since the flywheel has been removed before, and absent the shaft, not much holds the rollers in place.
If a replacement clutch is needed, it's a standard item that can be purchased for a few dollars at a bearing supply. A puller can be made with a large bolt, heavy washers, and a short piece of tubing, but if I need to explain in detail how to do it, you should leave that operation for others. For most machine shops it would be a routine task to pull and replace the roller clutch, if that is what is required. It would probably be cheaper than purchasing a new flywheel assembly from C2.

[Carl Watts]

Whats important is you don't use a hammer at any point in the operation.

The bearing is a very tight press fit and it only goes in ONE WAY as it locks onto the shaft in one direction only.

There are different options on the bearing. I upgraded the standard KOYO bearing to the KOYO RC-121610-FS one with stainless steel leaf springs.

Search the posts, I put up some information a while ago.

[jamesg]

On Cs, the knocking can come from the lock system joining the rail to the flywheel asy. A touch with a hammer to tighten it can sort that immediately, if we hit it in the right direction.

[johnlvs2run]

For most machine shops it would be a routine task to pull and replace the roller clutch, if that is what is required.

IIRC, that's what I did with the model B, and it was quick and easy.

[johnlvs2run]

Here is the post:

I took the model B flywheel to a local machine shop.
They pressed out the old clutch for $20 and put in the new one.

I didn't do anything else to the clutch.

By the way I'd done at least 24 million meters with that clutch in the flywheel.

[rakserv]

if you take a video of it and send it to concept2 support they are most helpful.

rowing@concept2.com

i had a similar problem with a drive train upgrade for a Model C, they had me replace parts that they sent me.

see video: https://www.youtube.com/watch?v=nylOVDrrWlc

[froque]

Hi rakserv

what was the reason for the poping noise?

cheers

[rakserv]

hello -

when pulling on the drive it felt like and sounded like the clutch was slipping before engaging on the axle
since i had replaced the entire drive train (flwheel axle, bearings, sprocket, chain and idler pulleys) with new components ... it was a mystery to me and i thought it was something to do with the clutch since i had not replaced that. so to experiment i replaced the flywheel as a troubleshooting step ... behavior was still there ... i recalled that it was a very snug fit getting the flywheel onto the axle so i ended up replacing the flywheel axle and sprocket ... problem resolved.

so i am not certain if it was the sprocket or the axle but the popping nose went away ... my suspicion is that it was the flywheel axle but i don't have definitive troubleshooting to tell me that was the case.