Boxerworks.com

I have the 80mph speedo (1.078) on the bike with 33:11 FD now, and today I rode it to work, with a gps to "validate" the speeds against kph.

The speedo...
@ 38mph (61.1) shows gps speed 60kph
@ 50 mph (80.5) shows gps speed 80kph.
@ 63mph (101.4 kph) shows gps speed 100kph.

That's pretty close, even considering the gps in the tank bag method might add a minor error in eyeball co-relation of the speeds.

Thats close enough steve.........

When we have a ride next time I would like to compare it with mine to see how far out mine is...

50 mph = 80 kph is really OK!

Jean wrote:50 mph = 80 kph is really OK!

Can't get much better than that huh! Bear in mind, the gps was in the top of the tank bag, under a clear cover, and I had to co-relate the two speeds from the two places as simultaneously as possible, whilst riding in traffic on the tollway.

That sounds dodgey I know, but the traffic was very light at 2230 hrs. The technique does lend itself to slight error in the numbers, but close is still close regardless I think.