by Andy Rose, edited by Joe Grogan and Andy Mapple
There are a total of nine slalom "Pull Type" settings. They are: A1, A2, A3, B1, B2, B3, C1, C2, and C3. Following is a brief review of how the system works and the information you need to select a setting.
Once the boat is stabilized at target speed, the primary factor causing it to deviate is skier loading and unloading. The system will respond to a negative speed deviation (e.g. skier load), by increasing engine rpm. Conversely, the system will respond to a positive speed deviation (e.g. skier release), by decreasing engine rpm. This rpm change varies in both rate and amount. The settings of A, B, or C primarily determine the rate at which engine rpm is modified in response to speed deviations, while the settings of 1, 2, or 3 spread the load resulting from those rpm changes. At the same time, the system works to achieve its goal of maintaining the average speed down the course as close as possible to the target speed.
The best and most consistent results can be obtained by matching your skiing style with the system’s programmed response to speed changes as shown below. A recommended strategy is to first select a letter, then a number. The types of pulls can be summarized as follows:
A -Slower engine response out of the buoy, but the boat will tend to move ahead as the skier approaches the buoy. B -Moderate engine response compared to A and C. C -Faster engine response out of the buoy, but the boat will tend to hold back as the skier approaches the buoy.
1 -Requires the lowest amount of load before the system initiates an rpm spread. This provides for a softer pull behind the boat. 2 -Provides for a moderate pull behind the boat as compared to 1 and 3. 3 -Requires the highest amount of load before the system initiates an rpm spread.
(Note: If you are new Zero Off user or not sure, a recommended starting setting is B2.) (Note: If you are transitioning from a previous tournament approved version of Zero Off, use your letter + the number 3. For example, if you have been skiing with letter A, then use A3 in order to receive the most similar pull to the 2008 version. The same rule applies to B and C.
Examples of when a lower letter and/or number might be appropriate:
• Skiers primarily concerned with getting the softest possible pull behind the boat. • Those who are light or lightly load the line. • Skiers who tend to break, overturn or have less than optimum body position out of the buoy. • Deep shortline skiing as a lower setting helps counteract the natural robust acceleration of the pendulum swing. Examples of when a higher letter and/or number might be appropriate: Â• Skiers primarily concerned with being released from the boat coming into the buoy. • Those who are heavy or heavily load the line. • Skiers who tend to be in good skiing position out of the buoy.
Other considerations include strength, conditioning, proficiency, attempting a new line length, etc. Experiment with various settings to find out which works best for you.
ZERO OFF CHARTS
Zero Off ver Q (my theory by Dave Satterfield 5/14/2009)
Here are my thoughts. It is much more complicated than the below, but in it's simplest terms, here is how I interpret the ZO descriptions. The boat is constantly trying to stay at a steady speed, but for this discussion, I am keeping it simple.
The problem I have with their descriptions is that they reference 'when the skier rounds the buoy.' Well, we all round the buoy at different times and usually different times at each turn. We also all load the boat at different times. Some load right out of the turn, some don't load until behind the boat.
For this reason, I reference the 'moment of load.' The boat does not know to do anything until it senses it's speed slowing down. This 'moment' could be right out of the buoy, behind the boat, or free skiing. It's just when you start to slow the boat down. Once that moment of load occurs, the boat must compensate by increasing RPMs. How it does that is where we get the ABC123. The letters (A, B, C) are the difference in time where the boat starts to increase RPM. 'A' will have the most delay and 'C' will have the least. This means at the moment of load, C will start increasing RPMs the quickest, while 'A' will have the largest delay.
The numbers (1, 2, 3) are the intensity and duration of the RPM increase. '1' will have the smallest amount of RPM increase, but for the longest duration (long and soft). '3' will have the highest RPM increase, but for a short duration (short and hard).
A1: Will have a delay after you start pulling. It will have a long soft pull. A3: Will have a delay after you start pulling. It will have a short hard pull. C1: Will start pulling right after you do. It will have a long soft pull. C3: Will start pulling right after you do. It will have a short hard pull.
Please note that this is my theory from my experience and talking with others, which has not been confirmed by ZO. I welcome input from everyone.
I have not pulled enough skiers to recommend one setting for a certain style yet. We are all experimenting at the moment. I can tell you that as a 'new school' skier, I do not get wide enough with the 'C' settings. I seem to get the earliest and widest with A3, but I am not in good enough shape to hold the pull sometimes so I usually end up on A2.
Another case we ran into yesterday. Skier (on A2) was making a good turn, pausing, giving up some angle, then accelerating. It looked like what would happen with the ski turning too hard, but it wasn't. We moved him to C2 and it completely went away. C2 picked him up earlier, which for him, eliminated the pause.
Below is a graphical representation.
The vertial plane for each curve is the amount of RPM increase. You can see that the '1s' will have the least RPM increase and the '3s' will have the most.
The horizontal plane is the duration of the RPM increase. This is not representing any buoys. Remeber, different people pull at different times, intensity and duration. It is a general time representation from the moment you start pulling.
Dave's ZO Chart
Steve, (by Shelby Coke)
This past winter and spring there has been non-stop internet chatter as well as dock talk regarding the new Zero Off settings. After combing through as much information out there, we had the idea to try and graphically represent what these words mean. With this in mind, our graphs were spawned to create a starting point; especially considering a picture is to be worth 1,000 words.
Our intention was to visually represent the ZO: ABC-123 settings from the Zerogps website FAQ, skiers inputs, Freddy K’s descriptions and a few other documents. So with that said, we created these theoretical graphs in Microsoft Excel based on information, skiing various boat & sites as well as talking to different skiers. Everything is subject to change but at least it’s a starting point. These graphs have been sent to ZO for feedback; they checked them out and conceptually agreed with them but they are not an “end all, be all” nor are they “official” from ZO.
A problem with all this is assuming a fluid smooth ideal skier. We all get behind sometimes in our passes and occasionally excessively pull on the rope, which changes things.
An additional problem faced is the debate of a 34mph skier vs a 36mph skier. Do we run the same settings? Do we need a different setting to “maintain more speed” or need a different setting to help us “decelerate into the buoy”?
Regarding the graphs, I showed everything to the same exact scale on the graphs. One Ball and Two ball were shown to graphical scale in relation to each other and the centerline of the course. Star Gazer shown on the graphs is shown from three ball to 4 ball as that’s when it was supposed to “engage” in older versions.
One thing we believe to be true has Star Gazer(SG) picking up the skier earlier and ending the skier later. This causes the RPM to be spread across a longer band of time therefore the skier does not feel the jerk of the pull as much as well as a skier can get behind and make their position back up.
From the documentation and pulls behind the boat, the letter settings of A-B-C directly represent moments “in time” when ZO will react to the skier. The setting of A should be reacting to the skier “later in time” in relation to the setting of C. Therefore, C can react to the skier immediately out of the buoy. B will be incrementally later than C with A setting being eligible to activate the latest of the three settings.
Again, from the documentation and pulls behind the boat, numerical 1-2-3 describes the threshold of when ZO reacts to the skier. A setting of 1 has a lower amount of input before it engages: as soon as you load the rope, it reacts. A setting of 3 has a higher amount of input before it engages: if you load the rope, you must load the rope enough to break the necessary pre-set higher threshold, and then it engages.
The B-2 of ZO shown in my graph has the same similar curve as SG but notice a few things: 1) It is shorter in length; which means it will have to be more powerful to still maintain the same split times. It has less "time/length" to do its work to keep the boat timing exactly correct from buoy to buoy.
2) It is higher, which is a function of the rpm having to be applied in a shorter length.
For the comment of having one master graph, I tried that but it ends up with a complex of unreadable matrix lines, considering it will be 9 options, +1 for SG, +1 for PP Classic. It didn’t work very well but I can do combinations at the individual’s request.
All these graphs are theoretical based on documents, subject to change as more information comes to light as well as P101 now "Q100" being officially released AND of course the weather warms up with everyone skiing again!
Whether the graphs are “right” or “wrong”, the goal is try and visually represent words on a page that affect all skiers. Getting skiers thinking about what the words mean is a great side product.