sigma bc1606L wheel size input for my cagiva.

[befdelta7]

hi,

i have a sigma bc1606L cycle computer, and cant get my head around setting the wheel size. anyone know what numbers to input in the computer for my wheel size?
my wheel on the bike is 110/70/17.
or know of the easiest way to calculate the wheel size? read somewhere that you position the valve at the bottom of the wheel then roll the wheel forwards untill the valve is back at the bottom, then measure the distance travelled im mm... but not sure what to do after this. take the distance in mm and divide it by 1.61(mile)??
iv no idea, anyone got any ideas?

cheers,
____________________
Dont do a wheelie in front of a traffic copper... it gets you 3pts and £220 fine.

[G]

Most push bike style speedos require you to put the size in, in mm or cm. Some do require you to divide the circumference by 1.61 if you require the output in mph rather than kph.
All depends on the model.

You can do the putting the valve on the ground and measure the distance. Someone else mentioned a dab of paint on the tyre then meausre the distance (or tippex). Alternatively a bit of string around the centre of the tyre will also do it.

[befdelta7]

thanx G

the computer i have has the option of kph or mph. i think im going to do the "roll out" test, sounds easiest. so with the computer having the option of kph-mph means that i dont need to divide by 1.61 do i??
the thing is that i dont have a speedo to compare with when setting up the computer, so i need a way to set this up quite accuratly. thanks for the replys.
____________________
Dont do a wheelie in front of a traffic copper... it gets you 3pts and £220 fine.

[G]

[befdelta7]

right it shows in the manual,
a little diagram of a bike front tyre with a measuring scale below it, it has:

km/h:
WS = mm

mph:
WS = mm

beside the diagram.

does that mean that selecting the mph option, i dont have to divide by 1.61?
____________________
Dont do a wheelie in front of a traffic copper... it gets you 3pts and £220 fine.