Racing a 2-

bmcgraw · Post by **bmcgraw** » April 3rd, 2008, 11:22 am

Hi--

Recently started racing a 2- (2000m) and have a question:

In a pair with a notable power difference, the "weaker" rower is in bow, which I was told is the initial step to try to even out power differences. The boat in this case still turns to the starboard side.

Our pairs have steering hooked up to one of the four shoes. Steering, from what I've been told, is far from ideal as it offsets the boat, etc. Is it better to leave the steering engaged for the majority of the race to help even out the balance or to have stroke seat row with lighter pressure?

Also, if anyone has links to articles or even book suggestions where this is covered in greater detail I'd appreciate it.

Thanks

PaulS · Post by **PaulS** » April 3rd, 2008, 12:35 pm

You need to get some form objective speed feedback in the boat (SpeedCoach, Garmin Forerunner 201, etc...) and determine what effects your speed the least.

Slight constant rudder is not optimal, but can be countered if it's little enough.

The first thing to try would be easing up to what is required to simply go straight with no rudder, observe the speed, then add power and countering rudder in small increments to see if speed can be increased.

There may well be some rigging considerations that could help the bowman, and most of that can be done by changing only the oar (relatively easy to do), but will require it's own set of testing.

Gus · Post by **Gus** » April 3rd, 2008, 7:21 pm

I was hoping Paul would know of some testing that could be referenced to help you with the decision of what to do, but was thinking it was unlikely that there had been testing by anybody of how much rudder usage affects boat speed. Obviously it slows it down, but how much in comparison to other adjustments is not something that I'm aware has been documented. It's my experience that the use of rudder to control the course usually leads to a extremely sloppy course as you use the rudder back and forth to control the boat.

As Paul said there are adjustments with the setup of the oar that could be helpful. Personally, we disconnected the rudder on pairs and steer strictly by power. In our case, the stronger rower was in the bow and through his strength advantage steers the boat as necessary through power adjustment. All the stoke had to do as the weaker oarsman is row. Bow being stronger had the reserves to take care of steering.

Another thing to think about is not just the sheer power difference but the application of power by each rower. Ideally in any boat all the oarsmen should match up their power curves identically. This is even more important in a pair. Applying power at non matching points during the stroke can greatly affect a pair. At a minimum you might want to match up power curves on the erg using the PM. Better still is Paul's Ergmonitor program which is more useful and accurate. You could also pair the ergs up on slides which will help identify differences in power application between the pair.

Good luck.

PaulS · Post by **PaulS** » April 4th, 2008, 12:10 pm

Gus wrote:I was hoping Paul would know of some testing that could be referenced to help you with the decision of what to do, but was thinking it was unlikely that there had been testing by anybody of how much rudder usage affects boat speed. Obviously it slows it down, but how much in comparison to other adjustments is not something that I'm aware has been documented. It's my experience that the use of rudder to control the course usually leads to a extremely sloppy course as you use the rudder back and forth to control the boat.

As Paul said there are adjustments with the setup of the oar that could be helpful. Personally, we disconnected the rudder on pairs and steer strictly by power. In our case, the stronger rower was in the bow and through his strength advantage steers the boat as necessary through power adjustment. All the stoke had to do as the weaker oarsman is row. Bow being stronger had the reserves to take care of steering.

Another thing to think about is not just the sheer power difference but the application of power by each rower. Ideally in any boat all the oarsmen should match up their power curves identically. This is even more important in a pair. Applying power at non matching points during the stroke can greatly affect a pair. At a minimum you might want to match up power curves on the erg using the PM. Better still is Paul's Ergmonitor program which is more useful and accurate. You could also pair the ergs up on slides which will help identify differences in power application between the pair.

Good luck.

I'd like to know of any objective data on rudder use also, but suffice to say that it adds considerable drag and would quite likely be better left to minimal use.

While the matching of force curves is an excellent thing to do, there is a single exception, which happens to be in the 2-, due to the differences in turning moment from the stroke and bow positions. If both rowers are equally powerful, it will benefit the boat for the bowman to have a bit later peak in pressure, which keeps the boat from being "pulled around". This has been documented with data from Elite 2- rowers, and also in the Book "Rowing Faster". That said, if the bowman is a bit weaker they might well overcome the issue by getting to peak more quickly (even the stroke consciously slowing to help) and see if it can be worked out that way.

We also tend to row 2-'s without a rudder to make sure to train sensitivity to course management through power application alone.

Gus · Post by **Gus** » April 4th, 2008, 3:55 pm

PaulS wrote:If both rowers are equally powerful, it will benefit the boat for the bowman to have a bit later peak in pressure, which keeps the boat from being "pulled around".

This sounds just the opposite of what I would think it would be. Due to the bow's position advantage, would not a later peak of pressure tend to pull the boat around even more so. I would think that later peak pressure by the bowman just increases the position advantage of being in the bow. I'm sure you will explain to me where I'm thinking incorrectly.

PaulS · Post by **PaulS** » April 4th, 2008, 4:38 pm

Gus wrote:
PaulS wrote:If both rowers are equally powerful, it will benefit the boat for the bowman to have a bit later peak in pressure, which keeps the boat from being "pulled around".
This sounds just the opposite of what I would think it would be. Due to the bow's position advantage, would not a later peak of pressure tend to pull the boat around even more so. I would think that later peak pressure by the bowman just increases the position advantage of being in the bow. I'm sure you will explain to me where I'm thinking incorrectly.

The late peak is less efficient in accelerating the boat so lessens the effect on the turning moment from the bowmans position. There is a Rowing BioMechanics Newsletter that addresses this but I can't locate it at the moment and will have to get to my hard copies to search through them quickly. Remember, it's for equally powerful rowers, if they both had the preferred early force peak then the bow would pull the boat around and could hold some power in reserve while going straight. These "perfect matches" in the 2- are most likely a result of chance, at least prior to tools like ErgMonitor existed. And even then, there is no guarantee that once bladework is involved that the force profile will be maintained from what was measured on the Erg.

Gus · Post by **Gus** » April 4th, 2008, 7:23 pm

PaulS wrote:The late peak is less efficient in accelerating the boat so lessens the effect on the turning moment from the bowmans position. There is a Rowing BioMechanics Newsletter that addresses this but I can't locate it at the moment and will have to get to my hard copies to search through them quickly. Remember, it's for equally powerful rowers, if they both had the preferred early force peak then the bow would pull the boat around and could hold some power in reserve while going straight.

Thanks for the further explanation. It wasn't really very helpful to me as to the why until I started to think about it more. I'm not sure where my brain was earlier, but it's not the position of the oarsmen so much as the position of the blade during the stroke and at the catch the blade is in the strongest position to turn the boat and the bow has an advantage because their blade is ahead of the blade of the stroke and would be able to pull the boat around with a stronger early peak. There I think I have it. Correct me if I'm wrong.

Another aspect of this goal to balance the power properly is the need to avoid the fishtailing motion of the boat. Anything that take power away from propelling the boat forward and applies it in a sideways force is going to slow the boat down.

And, since we're the only ones using this thread, I'll take it off topic by asking what support is there for the prevailing opinion that a boat with heavier oarsmen has an advantage in a headwind? Figure you'd know since you know everything else.

Bob S. · Post by **Bob S.** » April 4th, 2008, 8:33 pm

Gus wrote:
PaulS wrote:
And, since we're the only ones using this thread, I'll take it off topic by asking what support is there for the prevailing opinion that a boat with heavier oarsmen has an advantage in a headwind? Figure you'd know since you know everything else.

Actually, Gus, I have been following this with interest, but just haven't felt that I have any comment to make. But your headwind reference inspired me to chime in. I would think that it would be a matter of momentum during the recovery. I vividly remember an experience almost 75 years ago when I was rowing a high prowed skiff against a head wind that was gradually pushing me towards the pilings of a wharf. Fortunately some one spotted my predicament and came out with another skiff with an outboard to toss me a line to pull me in. It was very frustrating to make a little headway on the drive and lose all of that plus a little on each recovery. I now wonder what my stoke rate was on that wild ride. The boat had a fixed thwart, of course, and short, gunwale-mounted oars, and I was just a little guy (9 or 10) so I suspect that it was pretty damn high.

Bob S.

PaulS · Post by **PaulS** » April 5th, 2008, 11:32 am

Gus wrote:
PaulS wrote:The late peak is less efficient in accelerating the boat so lessens the effect on the turning moment from the bowmans position. There is a Rowing BioMechanics Newsletter that addresses this but I can't locate it at the moment and will have to get to my hard copies to search through them quickly. Remember, it's for equally powerful rowers, if they both had the preferred early force peak then the bow would pull the boat around and could hold some power in reserve while going straight.
Thanks for the further explanation. It wasn't really very helpful to me as to the why until I started to think about it more. I'm not sure where my brain was earlier, but it's not the position of the oarsmen so much as the position of the blade during the stroke and at the catch the blade is in the strongest position to turn the boat and the bow has an advantage because their blade is ahead of the blade of the stroke and would be able to pull the boat around with a stronger early peak. There I think I have it. Correct me if I'm wrong.

That's an interesting way of looking at it, and very illustrative from an intuitive point of view. Though since the oar can only act on the boat through the pin, it's not technically correct. Not to worry, we describe all kinds of things in rowing with intuitive, rather than precisely accurate terms. i.e. "Let the blade fall into the water on it's own." (very common catch coaching mantra), when in fact, gravity would not provide nearly the speed at which the blade needs to enter the water at the catch (Well, for the type of catch one would want to have.). Fortunately, unweighting our hands while holding the handle results in placing the blade more quickly than gravity will do.

Rowing Biomechanics Newsletter
Particular articles of interest:
2002/4 - #13
2006/12 - #69

Gus wrote: Another aspect of this goal to balance the power properly is the need to avoid the fishtailing motion of the boat. Anything that take power away from propelling the boat forward and applies it in a sideways force is going to slow the boat down.

And, since we're the only ones using this thread, I'll take it off topic by asking what support is there for the prevailing opinion that a boat with heavier oarsmen has an advantage in a headwind? Figure you'd know since you know everything else.

This is a tough one, and I do side with the conventional wisdom for a few reasons.
1) The Hwt boat, once underway, has greater inertia.
2) Both boats will have very similar blade area exposed to the headwind, and the slightly higher body area is a very small percentage of the total exposed "wind catching" resistance.
3) It's very likely that the lwt crew would rate higher, giving them more total blade area exposure to the headwind.
3a) The Hwt crew can put in more power per stroke, rate a bit lower for a given speed, and save a lot of drag from the blades. (lwts are limited by body mass as to the power per stroke that can be generated.)

That said, in perfect conditions the boat itself is enough of an equalizer between crews, though if you can manage to get the Opens to row as well as the lwts they will come out ahead because they can put more power into driving the boat, however that's a BIG IF, as the Opens tend to rely a bit more on strength than technique, and for the most part get away with it since they don't often have to actually race lwt crews in major competition. "So what the LM8+ got a faster time, conditions were different."

bmcgraw · Post by **bmcgraw** » April 6th, 2008, 2:50 pm

Thanks for all the help guys. Will ask our coach about changings in rigging to help balance power output. Also ordered "Rowing Faster" off of amazon today.