Scooterotica

Timbo wrote:Just fitted version 2, replacing version 1, running it from a standard cable. Measured wheel circumference. The speedo is 3-4 mph higher than a sat nav. How do I adjust? Also the Rev counter seems to be showing at half the expected revs. Any thoughts?

Is your satnav connecting to the right satellites? You configured it manually to make sure, didn't you?

...so I reduced the tyre circumference by 20 and the mph went UP by 4mph to approx 8 over throughout the speed range.....logic says I should therefore increase the original number of the tyre circumference but is that right.....not checked the satellites..

Mine was reading about 3 mph fast so I reduced the number by 2 until the speedo and gps lined up. If you are reading slow then you need to go up.

Keep in mind the circumference will change depending on the air pressure in the tire.

Do you have to put wheel circumfrence in if you are using the normal speedo cable?

Yes

And the gear ratio of the worm drive

rosscla wrote:And the gear ratio of the worm drive

Any idea what that would be on a GP 200 ?

Timbo wrote:

rosscla wrote:And the gear ratio of the worm drive

Any idea what that would be on a GP 200 ?

Covered here

http://scooterotica.org/forum/viewtopic.php?f=7&t=20931

Monty wrote:3 or 4 MPH out..... are we getting picky or what
Seriously you dont say at what speed. work out what % fast it is and reduce your wheel diameter by the %

3 or 4 mph out is the difference between a speed awareness course and 3 points.
Just saying.

Timbo wrote:

rosscla wrote:And the gear ratio of the worm drive

Any idea what that would be on a GP 200 ?

.77 is what most people set it at.