On Sat, 22 Jul 2017 23:42:24 -0000 (UTC), Mad Roger
wrote:

On Sat, 22 Jul 2017 11:43:15 -0600,
rbowman wrote:

It's a given that the speedometers on Japanese bikes are 10% high. The
theory is the manufacturers have no control over what tires will be
fitted in the future and are covering themselves over any legal
problems. "But the speedometer said I was doing 65..." On either of my
Suzukis that means I'm doing 60 and well under the posted speed limit.

The Harley speedometer is accurate. Obviously if the Japanese wanted
accurate speedometers they could do it.

The main point for bringing up the otherwise unrelated issues of
speedometer accuracy and repeatability is that some people here seemed to
think if they ran a calculation more times, that the "accuracy" somehow
(magically?) gets better because (magically?) their reading is low as much
as it is high.

Fact is...
The accuracy might get better.
It might not get better.

In the case of the speedometer, it will never get better because, often,
they always read high (on a given set of wheels and gears).

So just assuming that the gauge reads randomly below the actual speed as
much as it reads randomly high above the actual speed isn't going to get
better accuracy even if you run a billion speedometer runs.

It will always be wrong (by a certain amount high).
and exactly how is that germaine to the issue at hand? The speedo
means NOTHING. All we care about is the ODO - which will ALWAYS be
consistent, even in inaccuracy - so can be easily compensayed