Speedo cable revolution per wheel turn?

Guys, can anyone help me & measure how many revolutions the speedo cable turns per wheel rotation?

Im setting up my electronic speedo & i have no cable to disconnect at the clocks to find this out myself. Im running a 100/90-19 tyre & i know the rolling circumference is 2106mm but i need to divide that by the number of times the cable rotates per wheel turn to get an accurate speed measurement. I have no GPS sat nav to take with me on the bike or i could do it that way. I don't think a 77 750B2 Twin is capable of the 184.6mph i was doing yesterday!! :laugh:

You guy's using MPH instead of KPH?
Can you post the Brand/ Model of the Electric speedo, maybe a link to the company with a tech file?
If you still have the old Gear driven front hub set up, you can count the teeth, on each and get the ratio, or twist it in your hand and get a rotation #.

We're using MH & its an Acewell gauge, model no 2856 from the attached brochure. Im using the gear at the hub but with a supplied sensor cable with the gauge it makes an electronic pulse with each revolution of the speedo cable drive, if i disconnect at the hub i cant see in to count the revolutions & i have no mechanical cable to plug into the gaugh, my original mechanical cable was no good & was dumped ages ago or i'd connect it to the hum & find out for myself

Well it looks like i cant attach a .pdf file!?

www.acewell.co.uk/manuals/ACE-27-28XX-ENV3.pdf
I had to download and Install some Chinese Font stuff to display properly.
So you have a sensor that goes directly into the factory Hub speedo cable fixture? If so I would get the front wheel up off the floor, and remove the sensor. Then mark the tire, and place a piece of the old cable, if you have it, or another piece of something that will wedge into the square drive. Maybe put a small 90 degree attachment on the end of it to see better. Rotate the wheel and count the turns the cable end has gone.

Thats it, thanks dude. Im doing it correctly (the setting up) as im following the manual but i dont know how many rev's to divide the circumference by

Are you using one of these?
www.acewell.co.uk/Acewell%20Accessories%...le%20Drive/index.htm

Did you read this?


So here is from the 2856 Page, www.acewell.co.uk/Acewell%20Speedometers...tm?action=full&id=18

Motor Head wrote: Are you using one of these?
www.acewell.co.uk/Acewell%20Accessories%...le%20Drive/index.htm

Did you read this?

So here is from the 2856 Page, www.acewell.co.uk/Acewell%20Speedometers...tm?action=full&id=18

Yes i am using 1 of those instead of the cable drive, i ordered it as an extra.

From their website

Q: I'm using a cable drive converter, how do I calibrate the speedo.
A: Before fitting the acewell, it is necessary to find how far the vehicle moves with a single turn of the speedo cable.
Mark the tyre and ground, and push forward 1 wheel revolution - measure the distance travelled in MM.
Put a piece of tape on the end of the original speedo cable to produce a flag, push the bike forward 1 wheel revolution again, but this time count the number of revolutions of the speedo cable.
Divide the distance travelled, by the number of rotations of the speedo cable, and enter this number into the acewell.
e.g. If the bike moves forward 1700mm and the speedo cable turned 3 times, then enter 567 into the C screen

Did you get it Sorted?
Bump