Force curve for OTW rowing?

[Nosmo]

.....the rowers I know who really are fast (and do not just think they are) do not, in fact, have left-leaning force curves. Instead, they set the blade rather deliberately at the catch, build pressure on the face of the blade throughout the course of their drives and finish "hard." This is more uniformally the case among single scullers and more debated among those who row primarily in 8s, but it is generally true for all of the fastest rowers I know.

I don't know what the force curve looks like for the fast scullers I know but they do say that one should not have a very hard catch.

I was taught to row with and explosive catch in an 8+. After switching to sculling (1x & 2x), my speed improved quite a bit when I learned to deliberately set the blade at the catch (initially matching the speed of the boat) and accelerate smoothly through the drive. If I try to "finish hard" I tend to jerk my arms which does slow the boat. Still when I erg my force profile is still left leaning. The person I rowed with in a 2x was very smooth but his erg profile is triangular shaped but he does open his back early. Clearly in a faster boat one does have to accelerate at the catch quicker. It does seem to me that the catch has to be much subtler and more deliberate sculling then sweep rowing.

Frankly I don't know what to make of the various force profiles, but for me thinking about a hard catch slows me down and thinking of smooth acceleration through out the drive (without a particularly hard finish) makes me faster.

Edit:
Also by far the most important thing is not slowing the boat down. the people who are really fast can do some very quirky things but they don't slow the boat down.

[johnlvs2run]

Those with poor flexibility tend to compensate by setting the footplate to be less upright
(with the heel more toward the bow and the toe more toward the stern) and by setting it lower in the boat.

... both struggle when it comes to generating boat speed in part because (in the opinion of their coach) they have
very tight achilles tendons and can't get into a good position at the catch, and this despite quite a bit of fiddling with the foot stretcher.

I'm in that same boat, with relatively tight achilles and find the footrest angles way too steep, especially rowing barefoot.
This is easier to deal with on slides as I'm able to push the erg away with my feet, whereas the erg without slides doesn't move.

From my experiments, a higher footplate position make any angle easier to achieve.
For example if the feet were flat on the floor, then it would be difficult to raise them to a 45 degree angle.
Conversely, if the legs were extended directly in front, achieving a 45 degree or even a 90 degree angle with the feet would be easy.

Thus a 35 degree angle with high plates would provide a stronger base than a 47 degree angle with low plates.

I took my homemade wood footplates off the erg today, and will see about lowering the angle in the next couple of days.

[Byron Drachman]

Hi John,

A question for you, Spretzzatura - do you happen to know the range of angles of the foot plates used by single scullers?

From the FISA basic rigging manual:

http://www.worldrowing.com/medias/docs/media_350410.pdf

It has been found that a good position for the angle of the footstretcher
(see figure 5) is between 38-42 degrees. It has also
been found that a good position for the height of the footstretcher
(the vertical distance from the seat down to the heel of the footstretcher,
see figures 2 and 3) is about 15 to 18 cm.

There is also a lot of good information at Mike Davenport's website:

http://www.maxrigging.com/

Byron

[johnlvs2run]

Byron,
Thank you very much!
For comparison, the modelB was 40-41 degrees, the modelC and D are 46-47 degrees.
Cheers,
John

[Snail Space]

Also by far the most important thing is not slowing the boat down

How true. When I coach kids I spend most of my time persuading them to avoid trying to make the boat faster, but rather to avoid movements that slow it down. This is especially important for the boys who find muscle power irresistible!

As for force profiles, I'm not bothered whether it's central or left-leaning as long as it is smooth. If they ever turn into Olympians I'm sure the niceties of the curve will be ironed out - but not by me!

Cheers
Dave

[spretzzatura]

Point(s) well taken, Nosmo. What we THINK we're doing and what we are REALLY doing are not necessarily the same. It would be possible to think "soft catch" and still have a left leaning power curve. Somewhat apropos that general problem, Mike Teti tells a story about riding his rowers for a whole practice, telling them he wanted quicker catches. Finally, in frustration, he told them "OK, give me slower catches" and got what he was after. The only technology I am aware of that shows power curves OTW is put out by WEBA Sports. My one exposure to that seemed to confirm, at least for single scullers, that a soft catches and a deliberate build into the drive generated more boat speed.

It is also true that yanking on the oar at the end of the drive is not productive. Perhaps "firm" or "strong" would have been a better adjective for me to have used in relation to the finish than "hard." In fact, as far as I can tell, a powerful finish comes more from effectively timing the end of the leg drive, the body swing and the arm draw than by consciously applying extra force to any of those individual elements.

[johnlvs2run]

[anthonysemone]

Gentlemen,

has anyone devised a force measuring device for OTW use? If not, how is "force" measured OTW? I'm impressed with iBike for cycling which can be seen at www.ibikesports.com

tony

[anthonysemone]

http://www.weba-sport.com

tony

[Nosmo]

http://www.weba-sport.com

tony

What that is missing is a sensor for slide position/speed. Looks pretty cool though. Wouldn't mind having one. Wonder what it costs.

[anthonysemone]

2200 bucks US less VAT (?) and shipping.

tony

[mikvan52]

This is definitely not a hard catch, and the fast scullers that I've talked to in my club do not recommend a hard catch.

Comments on this advice?

Note to self (years later!)
Once the boat is at speed, it seems that meeting the actual speed of the water with the blade at the catch makes for an efficient use of power that does not disrupt the run of the boat... After all, we want to enlist as many of those watts as we can! More 'translated' watts means more boat speed.

[mikvan52]

Quite interesting observations (?)

I am sorry that the postings to this subject have died off .... (snip)

The reasons given, some of which have been touched on previously, are:

(1) While it is true that the legs are stronger than the trunk or arms, they are not all that strong in the compressed position at the catch. Only after the rower gets a few inches down the slide can the legs really start to exert their power.
(2) Efficiency is generally more important for racing than maximizing boat speed on any given stroke, so even if a hard catch were faster in the short term, it is very tiring and difficult to sustain, except perhaps for the very strongest rowers.
(3) If too much power is applied too soon in the drive, it is hard to continue to accelarate the oar handle and, as a result, the air pocket that forms behind the blade tends to collapse toward the finish and the blade tends to get "bogged down", making it hard to get a clean extraction. Messy finishes slow down the boat.
(4) Trying for hard catches tends to lead rowers to engage their backs too early in the stroke, principally because they are trying to maximize power quickly but also because that helps avoid "shooting the slide." Frequently, it also causes rowers to "miss water" because taking a hard catch requires exquisite timing. Both of these faults effectively shorten the stroke, which reduces boat speed. The timing challenge associated with hard catches also tend to cause rowers to put pressure on the footboads too soon, before the blade is in the water. Rowing the blade into the water causes boat "check," which slows dows the boat.

One final observation: If someone wants to throw a baseball as fast as possible, he or she would not be well advised to put maximim effort into the first few inches of the throw and let the last part tail off. The same would be true for hitting a golf ball as far as possible or jumping as far as possible or throwing a shot put as far as possible. In ever case, acceleration needs to build from the strongest muscles to the smallest, and in every case the last motion, whether it is the snapping of the wrist or the pressing of the balls of the feet on the ground, needs to be the quickest. And, that final quick motion needs to concentrate power from the initial efforts of the larger muscles into moving the ball or the body -- or a boat.

[igoeja]

I recently read Rowing: Olympic Handbook of Sports Medicine, http://www.amazon.com/Rowing-Olympic-Ha ... 1405153733, which you might find illuminating. It discusses the various stroke types, Adam's, Gringko, Rosenberg, etc., as well as the power profiles and the merits of each. My, very informal, take is that the front-loaded Adams/Rosenberg strokes have more power, but require more control on the recovery, while the Gringko stroke, using more leg drive and a later open, is easier for control.