DW

There was a remarkable increase in security at the 2002 Daytona event. Lots of air power constantly flying over to guard the area. It was pretty cool to watch.

Not that it is a big deal to those on this forum, but terrorism ended the Dakar Rally before it started. Instead of running through Northern Morocco right now, I am bag home in the USA (without 2 bags that were lost thanks to the airlines, one on the way and one on the return) lamenting the fact that I will get no race fix for a while. The Dakar rally is the first sporting event to get cancelled by a terrorist threat, it was made directly at the rally by Al-Queda #2 leader, so the organizers had to cancel the rally. Four French tourists and 8 military guards have been killed since December 24 in terrorist attacks in Mauritania. A written threat was then posted on the Al Queda website, denouncing "the cross" and the infidels and the focus of the ruling elite on the rally. Several of the race teams focus solely on the Dakar rally, it is the main race program for several manufacturers and the level of investment for this rally is staggering. Many teams spend several millions for this event, Mauritania was poised to benefit to the tune of $30 million Euros, etc... Sad day indeed. Might be some food for thought on making sure we can keep them from entering the USA and causing similar disruptions.

Yes, called canting in the snow ski world. Most snow ski bindings have a provision to cant the boots to roperly align your legs with the ski. Before that, hence the idea of using the washers, was to put plastic shims under the bindings to do the same thing. As Chuck mentioned, I did it to get a more natural stance on the ski and even out the on/off side turns. If you try it, you will need to get longer screws to attach the plate. I think for hardsells, I would cant the boot on the plate itself.

15" of snow in Michigan overnight! Lake is frozen, skates and sleds.

Trying to think positively, the HANS is now mandatory for all drivers in many series because of, particularly one of them, but actually 4 fatal accidents. There has not been one since with a HANS. In open wheel racing, moving the drivers legs behind the centerline of the front axle pretty much eliminated lower leg injuries. What is the device or innovation for waterskiing that will reduce or eliminate the lower leg injuries. That is what we need to focus on going forward.

I am always amazed at posts like that, IMO if you can't say it face to face, don't post it. A couple of comments to think about in no way incriminating the ski in question because I have no experience with one. Perhaps we should also realize where in the product segment most of the skiers on these forums reside, the very upper end, high performance area of the product mix. At that end of the spectrum, when the product is used at it's extreme's sometimes failures will occur. Sometimes those failures are related to the manufacturing of the product, but the reality is the failure rate on a high end ski will be higher than that of the average ski. It is in all other product lines. That is not an excuse for a defective product, but I certainly can't imagine any company that is passionate about thier product intentionally sending out something defective. I certainly don't condone sending out a defective product, but I also realize what I am getting in to when I strap on the ski and push it to the limit. What positive items can come from this incident: What caused the injury and how could it have been prevented assuming the ski broke? Should we mandate a binding plate to force bindings to stay together? Has the company been able to analyze the broken ski to determine root cause? If not, why not? Would a change in binding type have prevented the injury?ÂÂÂÂ

Just to add that other element to switching skis, mentioned by Ham, is ski to ski variability. You can certainly be on one ski and switch to the identical ski and not do well at all. So, how does one factor that in to the equation of when to buy a ski. Similar thing happens in other industries, many racers have their "favorite" car or motorcycle and they are actually all a little different. It becomes a real bummer when that favorite is destroyed in some manner and can't be reproduced. That gets to the quality control aspect of building skis. I also agree with Ham, my experience is that when a ski goes (the definition being when I notice a difference or think I notice a difference) it seems to deteriorate pretty quickly.

Dartfish is a really good tool, but it does require a separate operator to assist. We use it frequently in my line of work and it does help out. I got an interesting lead on some data aq. stuff at a recent trade show, more to come on that when we get something to share.

What's more interesting, driver musical chairs in F1 or skier's jumping brands, Stepneygate or Dr. Jim, Williams fuel temperature or Big Dawg rope length? Jayski devotes a whole webiste on Nascar rumors and gossip!

Intersting subject. Here is a little quiz, free ski behind three different boats then decide it you can or can't feel the difference. The wakes on the boats are all different and I think it makes a difference but might not show up in buoy count, as the skier will adjust to the given wake. Once skiing through the course and focusing on that aspect the wake difference seems to disappear. If you look at pictures, the skier cutting through the wake, the ski gets totally airborne. That is not a good thing to make the best wake crossing possible. Certainly, the pull has just as much effect as the difference in wakes so it all matters, just how much is the question.

That was a very nice boat, skied superb. My wife really liked it.

When Flint has better rock stations than Detroit, it's pretty bad. The reason XM was invented. Last time I checked, Walgreens in Mooresville was all sold out of the JV album (I am only repeating JTH's use of the music format). Did see an 8 track player in a restaurant in Baja earlier this year.

JTH, I don't agree with your thought that good / bad sides would swap. IMO a skier is by body geometry going to be able to have one side be better than the other and style and technique can't change that, only minimize it. Pure and simple, if you look at the ability to angle the ski relative to your hips, it will be much easier to do that by not crossing your legs. The technique only serves to reduce the body's limitations to twist or rotate in the less favorable direction.

John, When you go to Mooresville or Charlotte I can set you up with all "them" NASCAR country stations. BTW they have the John Boy and Billy show too. Thier version of rock is Lynard Skynard and Jazz just doesn't exist.

That is why I was thinking of using an accelerometer, it will keep up and have good fidelity. Add the GPS element for positioning. Might be able to input the balls as targets.

Don't underestimate your ability to use the data. A simple overlay of two runs will allow you to easily see what makes one run better than another or more specifically what section either improves or hurts any particular pass.

Strain gauge the line would give the rope tension, probably the second or third step in this process, right after JTH's hip angle measurement. That one should be soooo simple!

I would say the JB record is pretty big because it points out a big flaw in the process of running a tournament. The requirements to validate a run are prone to human error and it happened twice with the ultimate record in recent years. That needs to change so that records are approved, not disallowed due to lack of video, boat path or things outside the skiers control. You don't see too many timing errors in track and field or car racing, judging out of bounds on a football, tennis, baseball game is done routinely so there should be ways of validating a ski run pretty routine.

You might have seen some comments on the ZO system on another forum and some feedback from JTH here on his experience behind ZO, but here is possibly an explanation concerning the feeling behind any totally GPS based speed control system. We are using a data acquisition system on a race car and it uses a GPS to track vehicle speed with all other sensors direct wired in the the data acqusition system. Due to an interesting need to document vehicle data to one of the tech inspectors at a race, I discovered that there is about a .2 second lag in the GPS speed signal compared to direct sensor signals on the vehicle. I verified my findings by comparing the GPS speed signal to longitudinal acceleration, so I am pretty confident in the findings. Thinking about it and checking with a couple of people that deal with GPS systems, they concurred with my findings. It all has to do with pure and simple physics, the time it takes to get the signal from the object to the satellite and back which is about .2 seconds. With that in mind, a GPS controlled speed controller will at best react to speed adjustments .2 seconds after the change unless some sort of software is built in to compensate. I think that is probably the Stargazer approach to their system, use GPS for position, but engine data for actual speed adjustment or compensation from set point. I am not commenting on the importance or need to correct since ZO appears not to be correcting their signal and several people think it works, just providing insight on my findings. I feel that since the times are good for the ZO system the lag time does not hurt actual boat times.

There are several race car systems out there and the range in cost is quite dramatic, basically entry level at $500 up to F1 standards of $40,000 per car commercially (5 times that for unique systems (Ferrari / McLaren)). I don't think the data acquisition part is going to be the difficulty, it is determining the correct application, waterproofing and knowing what we really want to see / read. That usually takes some trial and error. I think we can find a light minimal channel system that will get us what we are looking for. I think once this gets going the expansion and next steps will really become interesting.

2 three axis accelerometers will do the trick. Not messy just need to orient 90 degrees from each other so they catch all six axis. Comments on data rate, I think we need to be more in the 100 Hz rate to get good data. One has to always remember that there are "bad" data points and if you get a peak between the points you miss it. I just think the relatively short time frequency of a ski run justify's more than 5-10 Hz resolution. Don't worry, I'm a cheap ba_t_rd so I will look for the low cost options out there. On the race car stuff, we allow low frequency for things that we feel won't change much or very fast, such as atmospheric conditions, oil pressure and temperature and things like that. Accel's. shock positions and things we end up being really interested in we usually go for 500-1000 Hz data fidelity. Shocks in particular, high speed is needed. For a short run like a ski pass or even several, memory won't be a big problem, we have a slightly bigger problem when we are storing a bunch of stuff for a long race.

Is there a hero like Evel in today's society? He captivated an entire nation with his stunts on a bike, who is there like that today? Nobody that I know of.

I think once you start to look at and analyze ski path data, you will really open up a minefield of information about not only yourself, but also if you expand and do comparative analysis with other skiers. This data will also tell you a lot about different skis and then as you get more detailed should tell you how a fin change works out, curing an area of concern or lack of optimum performance.

Drivers thought data acquisition when in it's infancy was ridiculous, now it is standard on every race car, used for car, engine and driver analysis. It could not only tell a lot about the ski but be a great training tool for skiers and ultimately ski schools. In engineer speak, data is king.

The key would be to attach a six axis accelerometer to the ski and you will have all the data you need off the ski. The interesting addition would be to track the handle and/or the CG of the skier to really see what is going on. Starting point would obviously be with the ski and progress from there. I really don't think we care if it is GPS based or not, if it can detail the path that works. Part of the trick will be the waterproofing of the sensor itself.