TECH: Setting wheelsize on Sigma Sport TARGA bike computer

[David Marsh]

Hi all,

I have a Sigma Sport TARGA bike computer, and the battery
has just died, and as luck would have it, I've temporarily
mislaid the instruction manual.

Luckily, the manual is available for download from Sigma
Sport's website.. (once you find the damn site, given that
it's a mess of Flash and therefore is virtually invisible to
search engines: mega-d'oh!)

..but it's not quite the complete manual. Bah.

I've sussed out how to re-enter my total distance [1] and
the current time, but no amount of semi-random button-
pushing on my part seems able to let me get into the mode
where I can re-enter the wheelsize into the computer.

Is there anybody out there who has this computer and can
help me out?

And while I'm at it, I need to make sure it's in the right
mode to measure in km, too..

Cheers,

David.

[1] I wish these things would give some warning as to when
the battery is about to die: as it is, I've had to re-
enter only a rough guesstimate as to what my total
distance is. As you know, These Things Matter!

--
David Marsh, <reply-to-email is valid at time of writing> |
Edinburgh, Scotland. [en, fr, (de)] |
http://web.viewport.co.uk/ |
>Please help me by correcting any errors in my foreign
>language posts!< Please trim & interleave quotes otherwise
>your posts will not be read<

 

[Anonymous]

David Marsh posted ...

> Is there anybody out there who has this computer and can
> help me out?
>
> And while I'm at it, I need to make sure it's in the right
> mode to measure in km, too..

I used to have a Sigma, can't remember if it was this
particular one, but ISTR that pressing and holding the
buttons in for 3 seconds got you into the menu for wheel
sizes, km/mph etc etc ...

--
Paul

(8(|) Homer rocks ..

 

[Msa]

In article <[email protected]>,
[email protected] says...
> David Marsh posted ...
>
> > Is there anybody out there who has this computer and can
> > help me out?
> >
> > And while I'm at it, I need to make sure it's in the
> > right mode to measure in km, too..
>
>
> I used to have a Sigma, can't remember if it was this
> particular one, but ISTR that pressing and holding the
> buttons in for 3 seconds got you into the menu for wheel
> sizes, km/mph etc etc ...
>
>
>

I have a Sigma but no the same model. To set the wheel
calibration I have to push the pin in on the back for x
seconds. Alternatively, what if you take the battery
out...doesn't it run through a set up mode when you put the
battery back in...i.e kph/mph, wheel size etc?

--
Mark (MSA) This post is packaged by intellectual weight, not
volume. Some settling of contents may have occurred during
transmission

 

[Zeeexsixare]

> Is there anybody out there who has this computer and can
> help me out?

You need to be in a mode other than the "CLK" clock mode.
Then you hold the button on the back. If you're in CLK mode,
it will set the clock.

By the way, the online PDF is pretty much the full manual. I
have the paper version right in front of me, and the only
thing it's missing is the wheel size chart and the list of
functions, which by now you should already know.

> And while I'm at it, I need to make sure it's in the right
> mode to measure in km, too..

You do that part while you set the wheel size.

--
Phil, Squid-in-Training

 

[Jobst Brandt]

David Marsh writes:

> I emailed Sigma and they emailed me back a spreadsheet
> with the sizechart the very next day. Excellent service!

> It's a bit strange: the manual's instructions say to
> multiply the wheel size in mm * 3.14, yet this gives a
> notably different answer to that in the sizechart. I went
> with the value in the sizechart since it seemed to sound
> vaguely familiar to what I'd entered originally (I'm using
> a slightly different tyre size now).

So why not just measure it accurately as is the method used
by those who want their speedometer to register correctly?
Because the rolling circumference of a bicycle wheel changes
with tire inflation pressure and load, to be accurate, this
measurement must be made with customary inflation pressure
and under normal user load.

To measure rollout circumference, place the wheel with its
valve stem directly over a mark on the floor and roll it
forward until the stem is again at the bottom while sitting
on the bicycle. Measure this distance as accurately as
possible and enter the number (usually in
mm) as the calibration number of the speedometer. This is
far more accurate than any table lookup or formula using
tire size.

Jobst Brandt [email protected]