Concept2 Forum

Right I have to admit I have stuffed up recently by putting too much grease in the clutch bearing but it was still a learning experience.

Not a big deal but at the beginning of rows it completely failed to engage, not much fun when you try and come out of the blocks fast !!!!

Still having thought it was stuffed some research on the Torrington RC-121610 bearing used revealed its the one piece acetyl resin spring version rather than the stainless steel leaf spring version.

Used the airline to remove all the grease and problem solved. Should it ever fail, the move will be to the RC-121610 FS version.

Probably a combination of too much grease, the cold weather causing the viscosity to be too high and it hampered the resin springs by "Sticking" the rollers.

"RC-121610 FS version"

I assume this is the stainless steel leaf spring version.

Interesting. Thanks.

Put too much on mine after a "clean" and it caused the flywheel to feel very unbalanced as it was slowing dowm on the recovery phase. Cleaned it all out and oiled it rather than grease and all good.

In two threads dated several yrs. apart, c2Jon posted first a recommendation of a "light grease" and later 3-in-1 or other 20wgt oil. I have applied heavy mineral oil once in 11MM meters of service and had no problems with delayed locking or noise during chain retract.

Steve1960VA wrote:"RC-121610 FS version"

I assume this is the stainless steel leaf spring version.

Interesting. Thanks.

Yes its the stainless version. The stainless version is also considerably more expensive but it will last longer and has what may be a clear advantage in your rower as stated in the data.

"The stainless steel springs permit higher rates of clutch engagement and achieve greater spring life"

Google Koyo RC121610FS. Anything that engages faster on the drive will give you a clear advantage.

The issue will be that its actually pretty difficult to replace. You would need to make yourself a bearing puller that remains dead centralized and use a long bolt through it to draw it out and then make sure you put the new one in the right way and then draw it slowly back in. These are NOT the kind of bearing you use a hammer on. No doubt Concept 2 have a custom setup involving a proper press.

"The stainless steel springs permit higher rates of clutch engagement and achieve greater spring life"

Noting that by "higher rates of engagement" they mean hundreds or even thousands of cycles per minute. These units are used in conveyor and other industrial applications where the cycles can be very high and the steel springs might make sense. We started using the plastic caged version in the Model B (price difference was not that much and not really a consideration) and found it to be a little quieter than the stainless version. Have never looked back and are still using the same unit in the C,D and E. Both units will have engagement issues if the lube gets too thick. C2JonW

A bit more research for anyone interested, the full Koyo catalogue is here.

http://www.neita.nl/pdf/koyo-torringtoncat.pdf

There is two pages of relevant information, pages 131 & 133 are worth reading.

Which of the two clutches better simulates a water catch with modern sculls?

jamesg wrote:Which of the two clutches better simulates a water catch with modern sculls?

I will let you know. Basically you want a very smooth and fast transition from it doing nothing to locking up. The Model C really has no noticeable "Dead band" where there is no resistance before it engages.

To be honest I don't think the clutch bearing in the Model D has ever been 100%, I have been running what is a very soft grease which is actually oring chain lube without any issues in the Model C since 2001.This is designed not to affect the orings and also resist fling.

The change to something thicker sure didn't help but even removing the grease it has not really helped so the bearing is toast.Its had a pretty hard time over the last 5 years or so with all the sub 20 spm rowing

Carl Watts wrote:A bit more research for anyone interested, the full Koyo catalogue is here.

http://www.neita.nl/pdf/koyo-torringtoncat.pdf

There is two pages of relevant information, pages 131 & 133 are worth reading.

I took a look at this. Interesting, though I might never have to actually go down that path. I presume an easier-to-replace item / assembly is available from C2.

Please forgive my ignorance - I've never opened the fan cage on my rower. Are these bearings / clutches pressed into the (steel ?) flywheel ? Thanks.

Yes the clutch bearing is a press fit, the two R8Z bearings are retained by internal C clips.

The steel bearing assembly is then held to the steel flywheel by 3 torx screws. They are torx because they are not to be removed or there is a good chance you will upset the balance of the flywheel.

The Clutch or one way bearing can be removed by making up a press tool as detailed in the data sheet.

I have successfully replaced clutch bearings in the past, be it much smaller ones in model cars. Once you have the right tools its not that difficult.

Will have a go at it, if all else fails its easy just to slip on a whole new flywheel.