A Modest Proposal – The Case for a Parabolic Speedometer

[daisy]

Originally Posted by TestDrive

I definitely don't follow the part about rise.

I've simply found that it's hard to judge intuitively how much speed will be required to coast to the top of a hill. I've come to realize that this is because the vertical distance is not a function of velocity, but of velocity squared.

Originally Posted by TestDrive

Let see how well I'm doing with the rest.

Let's assume the scale of your regular dial speedometer reads 0-110 mph.
Let's also assume that the needle sweep from 0-90 mph is 90*.
What do you want the needle sweep from 0-60 mph to be?

1. 60*
2. 40* (my understanding)
3. Some other number of degrees. (If so, what number?)

If the answer is 40*, I'd don't see why you'd need/want any additional scale markings other than km/h.

Yes, 40 degrees.

The speed markings (both mph and kph) would be on a parabolic scale. They would start out squnched together and spread apart as the speed went up. The rise (in feet/meters) would be a linear scale, just like the current speedometer.

What I think I'm going for is trying to get a better intuitive grasp on how much kinetic energy I have and how much drag I'm experiencing. Maybe it won't do a whit of good, or maybe I'll be surprised.

[wagonman76]

There are so many things that depend on getting to the top of a hill besides starting speed. Air temperature, wind speed and direction, tire pressure, road surface condition, current viscosity of lube in tranny/bearings/engine etc...

[daisy]

Originally Posted by wagonman76

There are so many things that depend on getting to the top of a hill besides starting speed. Air temperature, wind speed and direction, tire pressure, road surface condition, current viscosity of lube in tranny/bearings/engine etc...

This is true. And when I can 'feel' my kinetic energy, it will free up brain for thinking about them.

[daisy]

I just made my first mockup in Inkscape.



I can't remember the last time I exceeded 80, so the range shouldn't be a problem. It's already 15 mph over the highest speed limit here anyways!

[daisy]

I realized something else as I was explaining the merits to a friend: it also tracks the relative braking distance at that speed.

[daisy]

Eliminated the crowding on the lower numbers (anyone ever see a <15 mph limit?)

[Bicycle Bob]

Yes, I see sub-15 MPH limits, but not a lot of speed traps to go with them. I'd trust my estimate of my running speed.