Help <Sigma 600>

Alibi10 Jerry said:

I'm 1200 miles from home for the summer, and forgot to bring the
instructions for my Sigma 600 bicycle computer.
I had to change the battery and now I don't have the 4 digit wheel size
number.
Anyone know the number for a 27x23 road bike?
Thanks cause I'm screwed without the wheel chart.
...jerry

I don't know the number off hand. But if it's a four digit number, I'll
bet it's the circumfrence of the tire. Measure it out.

Put the valve stem at the bottom of the wheel mark a mark on the ground
at that point.
Roll the bike forwards or backwards until the valve stem is back at the
bottom. Make another mark at that point.
Measure the distance between the two marks.
I'll bet that number will be the number you need. Or darn close to it.
Close enough to make your cycle computer accurate enough for normal riding.

Ken
--
New cycling jersey: $49
new cycling shorts: $39
Not being a slave to the petrol pump: priceless.

Alibi10 Jerry said:

I'm 1200 miles from home for the summer, and forgot to bring the
instructions for my Sigma 600 bicycle computer.
I had to change the battery and now I don't have the 4 digit wheel size
number.
Anyone know the number for a 27x23 road bike?
Thanks cause I'm screwed without the wheel chart.
...jerry

If you mean 700x23, try 1325.

This page appears to have what you need:-

http://www.branfordbike.com/computer/comp13.html

Lewis.

*****

The Sigma booklet says 2133 (mm) but it's far more accurate to sit on
the bike and measure out what the actual distance is the wheel goes
with your particular tires and weight.

Thanks guys, got it going.
....jerry

I would second the rollout method as the best way to get a more
accurate odometer reading on a bike computer. The Sigma units don't do
any built in unit conversion for mile based readouts. If you want
metric then just enter the circumference in mm. For miles, divide the
circumference in mm by 1.61 (i.e. # km/mi) to adjust the scale.