Why does the track slope? OTW vs. erg question.

[PaulS]

Thanks Jon. Makes sense to me and I enjoy (and need!) the help I get from the slope on the erg.
Now we just need to establish whether there is or is not a slope to the tracks in shells. Some who have posted think there is, others do not. I'm pretty sure our Kaschper 8+s do not.
It could be a difference between skulling and sweep shells, or between singles/doubles and bigger boats?
Brent

I've heard of shells with flat tracks, but have never seen one in person. Of course my experience is limited to only a few hundred shells from a few manufacturers (Pocock, Hudson, Vespoli, Filippi, Fluiddesign, Empacher, Swift, Resolute, Carl Douglas, Owen, WinTech, Maas, Little River Shells, Alden, Pinert, VanDusen, and perhaps others that I've forgotten) so if there are boats being build with flat tracks, it's more of an anomally than a norm I would guess.

Just because the seat does not roll freely toward the stern, flat tracks can not be assumed, we borrowed an 8+ this past w/e that had very bad seats and in spite of sloped tracks it was considerable work to get back to the catch (for a number of reasons, but bad bearings were a contributor).

[Bob S.]

(for a number of reasons, but bad bearings were a contributor).

elliptical wheels would be more fiendish, but dirty tracks are more common. Of course they can be cleaned, but do they teach this early in the game?

Bob S.

[PaulS]

(for a number of reasons, but bad bearings were a contributor).

elliptical wheels would be more fiendish, but dirty tracks are more common. Of course they can be cleaned, but do they teach this early in the game?

Bob S.

Oh, no worries there, the tracks and wheels were disgusting, Once we got out in the rain it made for a nice bit of blackish water being splashed about. The old style seats have a stainless axle and hard polymer bearings that work well enough when new, but these weren't new, then as heat builds up (during the 5k row to the start line, they just got more gooey as we went. I'd have preferred a good old double action seat in this case, the single action seats really do need stainless sealed bearings on each wheel. My basic goal was to get through the event and remain unharmed by it and that one was met, so a victory of sorts.

[icomefrombirmingham]

Thanks Jon. Makes sense to me and I enjoy (and need!) the help I get from the slope on the erg.
Now we just need to establish whether there is or is not a slope to the tracks in shells. Some who have posted think there is, others do not. I'm pretty sure our Kaschper 8+s do not.
It could be a difference between skulling and sweep shells, or between singles/doubles and bigger boats?
Brent

I've heard of shells with flat tracks, but have never seen one in person. Of course my experience is limited to only a few hundred shells from a few manufacturers (Pocock, Hudson, Vespoli, Filippi, Fluiddesign, Empacher, Swift, Resolute, Carl Douglas, Owen, WinTech, Maas, Little River Shells, Alden, Pinert, VanDusen, and perhaps others that I've forgotten) so if there are boats being build with flat tracks, it's more of an anomally than a norm I would guess.

Just because the seat does not roll freely toward the stern, flat tracks can not be assumed, we borrowed an 8+ this past w/e that had very bad seats and in spite of sloped tracks it was considerable work to get back to the catch (for a number of reasons, but bad bearings were a contributor).

Hi Paul,
Yes, I had a good look at our boat last night and the tracks slope, quite a bit in fact....but not enough to overcome the friction of crappy bearings and accumulated grime apparently!
Brent

[johnlvs2run]

The modelB slope was quite slight, compared to the C and the D.

I leveled the railing on the B and C for awhile, and found NO difference as to ease of recovery, i.e. the slope didn't provide any significant assist to recovery.

It has occurred to me that C2 might have sloped the railing to give some assist to their low rate philosophy, i.e. so that "standing on the foot plates" would give some assist to low rates. Perhaps that is not the case but, if so, the fallacy of that is that the direction of momentum of the railing became GREATER than it was, as compared to the line of force from the cogwheel.

For that aim to be effective, the line of momentum needs to be CLOSER to the line of force. When the front of the railing was lowered, the cogwheel needed to be lowered by twice that amount (being twice the distance from the back legs) to maintain the same distance between the lines of force and momentum.

This is similar to a weightlifter lifting a weight from the floor. The closer the legs are to the weight, and the closer the lifter pulls the weight to the body, the easier and heavier the weight that can be lifted. The farther the feet from the bar, or the farther the bar from the feet, the more difficult the lift will become. It is the same way on the erg.

For the lines of force and momentum to be closer, the front of the railing would need to be raised. This in of itself brings the lines closer together. The lines on the modelB were 1.25 inches (10%) closer at the cogwheel than the lines on the C and the D! By raising the front of the railing to level, and ALSO lowering the cogwheel, these lines could be brought even closer together.

Here's an older thread about this, with a hypothetical "modelJ"
http://www.c2forum.com/viewtopic.php?p= ... model#6821

[johnlvs2run]

I lengthened the bungees a couple of inches this morning, then took a look at the connection in the middle of the erg.

The railing pieces came apart easily enough, and I put them back with the top piece moved forward to the front bolt position.

This held in place well but was too high to snap in place.

A similar top piece that sticks forward and down a bit should work well.

[Lincoln Brigham]

I wonder how many folks who have set up their erg in a garage are affected by this? The typical garage floor slopes about 1" down for every ten feet towards the door.

I'd been rowing facing out and then switched to aligning the rower sideways to the door and liked that better.

[PaulS]

I wonder how many folks who have set up their erg in a garage are affected by this? The typical garage floor slopes about 1" down for every ten feet towards the door.

I'd been rowing facing out and then switched to aligning the rower sideways to the door and liked that better.

The Erg rail typically has a slope of about 2" in 8ft, so you had added about 50% to what existed in the natural state. You could also reduce it by about 50% by having your back to the door.

I trained for about 6 months with an increase like that without thinking much about it. The rear set of slides happened to be level, but on a thick rug. The change back was noticable, but only for a short time before it became natural feeling.

[Lincoln Brigham]

You could also reduce it by about 50% by having your back to the door.

Yeah, but the view sucks!

[johnlvs2run]

I'm getting more interested to try the hypothetical modelJ.

A front rest for the fan cage should be easy to make, so the main issue will be the connection in the center of the erg.

If anyone has any ideas of how to adjust the the center connection for a hypothetical modelJ, let me know.