The original value gives a length of 7.67 miles. The newly measured value would give a length of 7.72 miles.
However, after reading up on this subject here, I think the original value might be more accurate, since I didn't load the bike during the measurement.
I also measured the course using Google Earth. The start line is easy to spot, since it's marked by the edge of the fire station driveway. The turn around looks like a small smudge on the road when viewed from space, it's just north of the second driveway past the woods. Here's a view.
With Google Earth, the course length I measured is 7.65 miles. However, that number has some uncertainty. It's calculated using an idealized spheroid model of the Earth. That doesn't include the terrain and the relative roughness of the road. Also the path I marked using Google Earth is a rough approximation of the route that a cyclist would take on the road and is probably slightly shorter than an actual rider's path.
So after all that, I still don't know how long the route really is. In fact, there's probably not a way to answer it definitively. I'll stick with the original value.
2 comments:
Over the years I have had TONS of guys ask me what the "actual" length is. I always tell them that it is whatever you make it. The length doesn't change at all so, being a time trial, you are only comparing the times and not the course. Besides, everyone comes up with a different answer as you found out.
It's one of those classic problems, like "how long is the coast of England?"
The length of the course is about 5,900 revolutions of my front wheel. So if the circumference measurement is "off" by 2 mm, that's 38 feet by the end of the TT!
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