Speedo accuracy?

[clogan]

I am the new owner of a 2010 Connie, and am wondering about the accuracy of the speedometer. On most other bikes I have owned, the speedo typically displayed a speed somewhat greater than that actually being traveled. This sort of error rate has created a market for a device known as the speedo-healer.

In today's ride on my Connie, I came across one of those radar machines that displays the speed limit, and then "your speed". The radar machine and my Connie's speedo were nearly identical: 45 indicated vs. 44 per radar. I was very surprised at the apparent accuracy of the Connie, and wondered if other Concours riders have found the speedo to be accurate over a wide range of speeds.

[ARS]

I once owned an old Yamaha with a broken speedo and timed the mile markers on the highway (i.e. at 60 mph your running a mile / min), then I just memorized the rpm's for different speeds.  You could do the same or bribe a trooper with some donuts 

[VirginiaJim]

Roughly 4.5%....as the crow flys.

[stevewfl]

gps

[Son of Pappy]

55s on the rear and she is dead nuts on using Steves method