Seat problem - concept2 model D rower

[dragos]

Hello,
rower model D was purchased in November 2020.
So far there have been no problems with it. Recently problems with the seat began. The seat swings left and right. There is no problem when you row slow or you just ride on the monorail up and down and lean left and right. But when you start rowing for real, after a while it starts to happen as if the seat starts to rise and after you pull it always hits somewhere and stops, so you can no longer row normally.
Rowing technique should not be a problem, because I never had a problem with rowing technique.
Seat rollers, lower and upper, have been replaced.
I tried re-tightening screws in case that made any difference, but they are tight enough.
I also tried to put the lower seat roller in the front hole, which is supposed to affect the seat being fixed, but nothing helps, the seat wobbles just like if it is in the center hole.
I really don't know what could be wrong now.
Does anyone know how to fix this?

Thank you

[NeilMac7]

Good question. My equipment is less than a year old. I too have noticed a wobble.

[WayHand]

Contact Concept 2, they will soon diagnose the issue. I had an issue that was technique related, which I realised before sending C2 film clips! My issue was not the same as yours. I was applying power too early and just before the catch leading to the pivot becoming unstable. C2 were excellent in examining photos to check the machine over. Hope you find the issue, best of luck.

[dragos]

Thank you!
I hope it's just something small, but I can't figure out what the culprit is.

[Joebasscat]

While I was warming up this morning my seat stop moving abruptly as well, dang shirt tail… Hope you get yours sorted out soon.

[dragos]

Hello,
here is supposed to be this problem: the frame is supposed to be slightly bent, which is then causing the seat of twist and bind up in some cases.
Well, I already looked at this once and it seemed to me that one was a little bent.
Does anybody knows what could be the reason for the frame to bend?

[Ombrax]

Does anybody knows what could be the reason for the frame to bend?

To answer this we'd probably need to know what the bend looks like.

Is it bent down, as if a 300 lb weightlifter jumped onto the rail?

Or bent laterally? (in which case the cause would be harder to guess)

[Tsnor]

By "frame" do you mean the rail? The rail is in two pieces horizontally stacked. One is a very thin stainless steel track surface that the seat runs on. The other is the monorail -- sort of an i-beam / box beam that holds up the track. The steel track is taped and riveted to the monorail.

A string will tell you if there is a bend in either. Given it's enough to upset the seat (!!!) it has to be a big bend.

Looking at it will tell you if the steel track shifted, or it there is a problem with the monorail beam that holds the weight. I can't imagine what could shift that beam (car hitting it? blowtorch?). Given the seat bumps and twists, is the stainless steel track on top of the beam somehow deformed or shifted off the track, maybe displaced vertically (gap between track and monorail) ?

Might be good to get a video of the problem. It's not clean why the problem would only happen when you are rowing for a while vs pushing the seat over a bent part or binding every stroke you take. ---> " But when you start rowing for real, after a while it starts to happen as if the seat starts to rise and after you pull it always hits somewhere and stops, so you can no longer row normally." Your rowing will not bend that monorail. Maybe the track gets loose after it warms up ???

(@ jackarabit I'm spitballing again, want to jump in and say what is wrong ?)

[dragos]

When you just move the seat a little, it goes left and right. It is possible that when rowing slowly, the upper roller can still line up with the monorail and drive back without problems. But when you start rowing harder and faster, this pressure is created, which then prevents the upper roller from being able to align with the rail. And because the seat goes left and right, it is on the monorail at that moment and because of this pressure it cannot align itself with it and it just wants to continue straight and because it cannot continue like that, then this jamming and stopping occurs.

Here is the link of the video: https://drive.google.com/file/d/1kBluhR ... share_link

[dragos]

Ok, I have tried with my friends frame in my seat assembly, but it's not that the problem.

[fischmeister]

What I see in your video looks pretty normal to me, at least it looks totally similar on my machine. Never caused me any problems. It only happens when I press on one side of the seat, never when I row and have my body weight centered.

[dragos]

I didn't have any problems either until recently. Now this can only be a problem as mentioned by Tsnor - the track gets loose after it warms up, while the track came off and then these problems started.

[jackarabit]

Transverse rocker is absolutely normal. You don’t want the under-rail rollers snugged up to the rail. You do want to center your weight and attempt a bilateral equivalence of effort and effort vectors from both sets of limbs.

I have no experience with delam of SS rail cover from the rower beam. If a loose rail top cover created a moving swale, I can imagine that might produce a wedging action between upper and lower rollers and create a stoppage. And the postulated separating rail is out of the chain of causality because your buddy’s beam is intact and the seat, transferred to his machine, persists in stopping or rocking or both? How about a video of your butt on the seat rowing in preference to hand palpating.