Tippo Meter

Has anyone any ideas on creating one?

Imagine being able to review a ski and produce comparable figures on the tippiness, the angles for primary and secondary stability and even an optimum paddler height/weight.

I'm not sure if all this would be possible, BUT, I've seen some very scientific responses in the surfski.info threads so I guess it is.

The design must be simple (think of the golf Stimp meter for green speed).

I'm thinking along the lines of a significant weight, cantered over the lowest point of the seat to be the the 'paddler' and a tripod that fixes to the foot block and back of the seat, with:
a vertical bar that can be set to various angles; and
a small weight that can be moved up the bar to make the ski tip.

As the small weight is moved up and out, the ski should start to tip and, in theory (?) provide the angles of stability. Various 'paddler' weights can provide a table etc.

I could be wrong and if so, I'm sure to find out, BUT, it may even get people to check in five of more times a day!!

Skis are basically unstable. There is no righting moment on a ski shape once it starts to heel, so it will capsize without a live paddler once it tips fractionally to one side or the other. A bit like a bicycle really. That is why tippiness has to be a subjective measurement and depends a lot on the shape of he paddler.

That's not a bad idea Richard, although Stuart is right. The stability of a ski & paddler combination is very dependent upon the height of the Centre of Gravity of the paddler. If we assume its near the belly button of the average person, then yes, most ski's are near neutral, slightly stable, or slightly unstable depending upon design.

However, in terms of a measure as you suggest, this could be done I think. Instead of dumping 80-90 kg of weight directly into the seat, the boat could be supported in a rig that applies a specified load and allows the boat to roll about a specific point (quite low down, simulating a low CoG). One could then measure the righting moment over a range of angles. Obviously this would be a relative measure, against a 'standard' or benchmark case, but potentially quite useful I think.

An interesting study in physics , hopefully it wouldn't be construed as a solid basis for chosing a ski. Way to many variables in body shape and CG.If there is a new ski paddler looking for a ski this might serve as a distraction from their need to actually paddle those skis they are interested in. If you were to buy the ski soley based on the results of the hypothetical tippometer you would probably get some very real lessons in applied physics. Sandy