Brand new SkiErg..clunk noise on double/single poling

[Keef]

Very new SkiErg, just delivered to home. 2days ago. only 12,500 mtrs so far
Not happy. Clunk noise from low down in body of SkiErg. Happens either on double or single poling.
Wall fixing bolts x4 just fine, both screws on mounting plate tight and no movement.
Base fixed to wall, no movement.

I have not noticed this clunk on the one I use at the gym, so far 1,090,501 this season. So would have noticed I guess.
Does yours make this noise from new?
Could this be some kind a bearing side 'slap' . Sort of thing you can get on a badly fitted bottom bracket bearing on road bike??

[Citroen]

Tomorrow, pick up the phone and call Concept2.

[Keef]

grrr ffs....removed R/H side panel.
place right hand on forward spool assembly (PN 2784)
set damper to max
pull down on right handle to 'catch' the flywheel but not spin.
notice upward movement of spool assembly.
SO its looking like forward 12mm bearing ( PN1315) is out of its cup (PN1013) ???!!
I am, to say the least, a trifle incandescent. Out of the box and not performing.
Citroen...yes certainly will call.

[johnlvs2run]

Let me know if you discover the cause. and a possible resolution.

[Keef]

I have short video clips which show the movement...but cannot seem to attach to post at the moment. ?

My observations:
Loose bearing at front of erg, this is the one that had detached itself. The rear bearing also has considerable movement in its cup.
I have hopefully effected some kind of fix, reducing the bearing movement by using a non solid packing material.

Spool Play: lateral movement in the spools on the axle, note no raised flange - is there an intended 3mm lateral play ?
If not, I will introduce a couple of packing washers to reduce this to about .25mm
The phosphor bronze spacers have no flange as shown in C2 maintenance movie clip.

As to what caused the front bearing to detach itself from its cup I still have no idea.
I can only think it was never assembled correctly.
When I have the time I will see if I can replicate this fault.

As a mechanical design it does not help having a non interference fit as is the norm in this type of bearing function.
This ensures bearing and cup remain in position during assembly and adjustment. As per Shimano HollowTech2 bottom bracket axles.

[Concept3]

I maybe have the same issue, also on a brandnew SkiErg. 100k onto it so far, have never used one before so i don’t know if this is normal or not. Now I guess it’s not.

https://m.youtube.com/watch?v=DCJOIZQoL7o
https://m.youtube.com/watch?v=-dkmxXi9VJI

[johnlvs2run]

Concept3,

My Skierg has that same movement with the spools, plus a double knocking sound, one at the start, and one at the end of the drive, which I think is due to the clutches catching up with the axle then releasing. I called C2 Josh about that soon after getting the erg, but there has never been a solution. Recently they sent a wave washer to add to the back of the axle, but it didn't make any change.

Regarding the spools, I had considered to add washers to lessen the distance they moved back and forth. C2 was not encouraging about doing that, but I still might try it at some point. The knock knock still is there but isn't loud or annoying. The noise on yours appears to be something different though, perhaps one of the swivel pulleys knocking at the top when it goes back and forth.

[Concept3]

Hello johnlvs2run,

Thank you for your reply. It’s not the swivel pulleys, it‘s the double knocking sound you describe. In the video i posted, at the beginning, you can hear the two knocks very close together. That is because i just pulled the handles a few centimeters at first. I also thought it must be a kind of a clutch sound. But i don’t have a sound like that on the rower when catching the flywheel. I’m overly happy with the skierg, it’s such a nice movement like on the rower. I just want to be sure it’s working correctly.

Cheers!

[Keef]

First off, excellent, as expected, communications and response from C2 UK.
Great, detailed support from the guys there. Talked me through a check list and at every exchange of mail, ended with the comforting ' we will send out new one if you want....then came the 'LockDown'

HOWEVER THERE IS A DESIGN FAULT
The clunk is definitely the result of the two bearings (PN1315), front and rear moving within their metal chassis cups.
If i could attach images ??? says 'too large' images are jpg 245kb 500 x 500px ?? better to explain.

anyhoo...
The 12mm bearings (PN1315) are first mounted in a hard 'neoprene' cup (PN1013), this in turn is then mounted in the metal cups welded to the chassis front and rear.
First I removed the fan housing, held the fan (PN2789) at sides and moved up and down. Result : movement.
I then removed the rear bearing cover PN1010 pulled down on handles, rear cup PN1013 with bearing moves up - drops down when handle released.
As does fan at front.

Next I removed side cover, held both spool/clutch assemblies (PN2784), moved up and down, found i could produce movement in axle.
Removed rear bearing thrust washer, dissembled pulleys, clutches etc.
Pulled the fan and axle out. Both bearings dropped out of their metal chassis cups.
Offered front bearing into chassis cup and found there is a two mm movement in the cup.
Repeated same with the rear bearing. Found same movement.
To prevent this movement I made two packing bands of 1mm hard rubber, 8mm wide with a length of the circumference of the neoprene bearing cup.
These are placed inside the metal chassis cup and the bearing and cup pushed hard into it.
Result no movement of the bearing.
Reassemble and now soak testing.
So far, from delivery on March 13 to March 29 have put in 87,227m. Usual mix of distance (@150W) and intervals (@312W)
No clunks noticed as yet.
I will disassemble and check packing fix @100,000m

This season I began with the SkiErg in the local gym. Total season 1,161,183m, did not feel any movement on that erg.
Fortunately bought my own just in time to be 'locked down' this past month.Phew.
Anybody from C2 tech care to comment please.

[Citroen]

Anybody from C2 tech care to comment please.

They don't usually visit this forum. It's run by volunteers.

Call Concept2 directly for support.

[johnlvs2run]

The clunk is definitely the result of the two bearings (PN1315), front and rear moving within their metal chassis cups.

The 12mm bearings (PN1315) are first mounted in a hard 'neoprene' cup (PN1013), this in turn is then mounted in the metal cups welded to the chassis front and rear.

To prevent this movement I made two packing bands of 1mm hard rubber, 8mm wide with a length of the circumference of the neoprene bearing cup. These are placed inside the metal chassis cup and the bearing and cup pushed hard into it. Result no movement of the bearing.

Well done on the great detective work and results! I wonder if that's the same issue with mine.
Has the movement become any easier and/or faster? What did you use for the 1mm hard rubber strips?
Skierg2 schematic

This season I began with the SkiErg in the local gym. Total season 1,161,183m, did not feel any movement on that erg.

If you haven't done so, you can add all of those meters to your log.

[Keef]

The clunk is definitely the result of the two bearings (PN1315), front and rear moving within their metal chassis cups.

The 12mm bearings (PN1315) are first mounted in a hard 'neoprene' cup (PN1013), this in turn is then mounted in the metal cups welded to the chassis front and rear.

To prevent this movement I made two packing bands of 1mm hard rubber, 8mm wide with a length of the circumference of the neoprene bearing cup. These are placed inside the metal chassis cup and the bearing and cup pushed hard into it. Result no movement of the bearing.

Well done on the great detective work and results! I wonder if that's the same issue with mine.
Has the movement become any easier and/or faster? What did you use for the 1mm hard rubber strips?
Skierg2 schematic

This season I began with the SkiErg in the local gym. Total season 1,161,183m, did not feel any movement on that erg.

If you haven't done so, you can add all of those meters to your log.

Hey, lost log metres ?? your concern is much appreciated..but no worries . I have a USB stick 'log book'. Carry everywhere I go, friends house, gyms at hotels etc. You never know when you might find a C2 erg hiding. BTW also a spare formatted USB stick that i can quickly swop out if any issues. I relay on USB stick hardware rather than wireless to tablet/phone. Have had dropouts and random glitches.

FYI: Shakedown Testing: so far since 'rubber strip' fix the last 80k has been clunk free?...I will strip down and check at 100k. Thats the SkiErg not me!
What type of rubber? its Weldtite 0.6mm Thick Butyl Rubber Repair Patch Sheet (155mm x 95mm) search for cycle/tube/repair/sheet should find it.
Note: do not use any adhesive.
Ask all children to leave the room.
Now, insert 12mm bearing (Part Number 1315) into plastic bearing cup (PN1023) then wrap the strip around cup and push into chassis bearing cup...patience ..you will need several goes!!! it will shift..or try putting the strip inside the metal cup..again patience and watch your language !!
Be aware you will need to fully remove pulleys, spools, clutches, fan etc to get to the front bearing. There good service videos on utube here.
https://www.youtube.com/watch?v=8g9PYn57hAA
Tip before removing green cord, clip clothes peg close to pulley, do not release the green and let it go, release gently. . It will spring up and fly off one or more of the tension pulleys.

[Concept3]

First off: You are very fit Sir with pulling that numbers at 65yo/78kg!

Thank you very much for the investigation work and reporting it here, great help. I‘m a bit scared to disassemble a brandnew machine and also i find it a bit disappointing. i have to think about whether or not i disassemble or get in contact with them for a new one. And if they send a new one who says it doesn’t have the same issue again. At least enough time available atm with the lockdown.

You can upload photos to an external host and copy the link in here if you don’t mind.

Cheers!

[Keef]

First off: You are very fit Sir with pulling that numbers at 65yo/78kg!

Thank you very much for the investigation work and reporting it here, great help. I‘m a bit scared to disassemble a brandnew machine and also i find it a bit disappointing. i have to think about whether or not i disassemble or get in contact with them for a new one. And if they send a new one who says it doesn’t have the same issue again. At least enough time available atm with the lockdown.

You can upload photos to an external host and copy the link in here if you don’t mind.

Cheers!

By the look of your video you have the optional stand, fine, this means you can swing the erg around and access the rear. Pull off the plastic bearing cap, you will then see the rear bearing. Do what you did with the spools, lift up and down and look for vertical movement in the rear bearing seating? or Have someone pull on the left handle hard several times to 'catch' the flywheel but not spin see if it moves
Thats for the external host tip...will do. Watch this space...
BTW, thanks for the big up, I come from a background of middle, long and ultra distance running. So,thats 20% body and 80% mind...or maybe lack of it??

[Concept3]

https://youtu.be/K3NX3v7KjiY

The rear bearing is not moving in it’s cup, i think the „clunk“ on my machine comes from the spools moving back and forward on the axis. In the video my woman is pulling with ~100W. When the right sidecover is dismantled the „clunk“ is less or even not noticeable but with the cover screwed on it is there again. Like a body of resonance. At the end of the video you can see an empty threadhole in the upper left corner. Here was/is a screw missing, from the inside it looks like this thread is not necessary. Just to mention.

Cheers