Measuring toe-in. I've enjoyed the recent suggestions on measuring toe-in including using lasers, curtain rods, and sighting along straight lines. I once contributed and sent in a suggestion (June 2002- Free alignment tools) on how to make an alignment tool (tremmel) using three scraps of wood, four fasteners and two nails. This reminds me of a physics problem:

You are handed a barometer and told to determine the height of a building. I am sure you can think of others, but among solutions are:

1) Count the number of barometer-end-over-ends to get from the ground to the top and multiply by the length of the barometer.

2) Measure the lengths of the shadows of the vertical barometer and the top of the building and use proportional triangles.

3) Drop the barometer from the roof and time how long it takes to hit the ground. Then use d=16 t^2.

4) Find the building superintendent and say "I'll give you this shiny new barometer if you'll tell me how tall the building is."

I propose a new physics problem: You are handed a barometer and told to determine the toe-in of a trike.

Here are some solutions. I am sure you can think of others:

1) Lay the trike on its right side with the right front wheel horizontal and measure the barometric pressures at the front and back of the left front wheel to get the difference in heights.

2) With the trike positioned as in 1), drop the barometer from the front edge and time how long it takes to hit the ground. Get that distance. Repeat from the rear edge and take the difference of distances.

3) Ask Pearre Chase (See Friday, May 30, 2003) if he will trade his GPS sensor for your barometer. Attach the GPS sensor to the rear edge of the left front wheel with your trike aimed east. Get your coordinates. Now roll forward one half circumference so the GPS sensor is at the front. Get your new coordinates. Take the difference in the latitudes, convert to distance in mm, and multiply by two.

4) Go to an alignment shop and tell the manager you will give him the shiny new barometer if he will measure the toe-in.

Are there any other methods to measure toe-in that we should know about?

Byron