Modern bikes with electronic speedos?

Hi folks.

Just wondering, do the modern electronic speedometers have a calibration
function, like the push bike trip computers?

Or are they as accurate/inaccurate as the old style needle type speedos?

regards,
CrazyCam

 

http://www.sporttour.com/motorcycle_accessory/speedohealer.htm

 

I installed one of these gadgets on my XX. It plugs into the speedo
sensor. Only took a few minutes to wire up. They sell different kits
depending on the manufacturer of your bike.
Australian distributor is http://www.amcmotorcycles.com/

There is an Australian made alternative called Yellow Box
http://www.yellr.com/ Cost about the same, but wasn't plug and play,
and the calibration wasn't as clever.

Nev..

 

Interesting...thanks, Nev.

Since you saw fit to get one of these things, does that mean that the
original speedo wasn't satisfactory, and, if so, in what way?

regards,
CrazyCam

 

So how do you cailbrate it? ie, how do you get an accurate speed
reading to tell the speedo that is what it should be reading?

 

Well, at http://www.blackrobotics.com/yb_faq.htm there is a link to
TFM, and a good bit of instruction as to calibration.

They recommend using the speedo/odometer test signs on the various
highways for an accurate 5 kilometre run, then adjusting on a plus/minus
percentage basis.

It's actually quite interesting to read their comments in the document.

regards,
CrazyCam

 

Weird how people seem to get swept up by the 'digital/electronic'
thing; is a digital thermometer more accurate than a mercury
thermometer? Definitely less. Are electronic scales more accurate
that a balance? Again, definitely not. You /can/ get more accurate
equipment, but it doesn't follow from the fact it's got silicon in it.

The only super-accurate digital speedo I have seen uses GPS to get +/-
0.1 kph. I know a guy in Queensland that makes them. On a bike, the
only way to mount them is with strong magnets.

 

I would highly recommend you don't use the 5 km interval signs in SA. In my
experience they vary by up to more than half a kilometre. i.e. 4.5 kms
apart, then 4.8, then 5.5. Probably measured and installed by referencing to
a Guzzi Veglia odometer.

Theo

 

People became unable to adjust power supply voltages in computers when we
got digital meters. They had no trouble adjusting the 4V to 4V on an
analogue meter but the digital meter would have them carefully trying to
adjust it to 4.00, rather than 3.99 or 4.01.

Were digital voltmeters more accurate? Hell yeah, and cheap as chips. I
still have a 1/2% analogue voltmeter from the '60s, which I 'rescued' when
we went to digital measure. I think it cost around $750 in 1967, more than
three months pay.

Theo
(A 1/2% meter ccontains only 1/10% temperature stabilised resistors).

 

Do you know how the old fashioned rotating cable type speedos work?

Compared to that, the push bike trip computer, which gets a signal for
each wheel revolution and keeps fairly accurate time, then calculates
speed, was a great leap forward.

Most GPS's have a speed function, and yes it is pretty bloody accurate.

Mate has a wristwatch type GPS, strapped to the bars of his bike.

Don't think much of the notion of strong magnets... none of my current
GPSs would pay a blind bit of interest!

BTW, in case you didn't know, speedos which have a needle going round a
dial, can still be driven by digital electronic signals.
Quite a few Suzukis are apparently thusly equiped.

regards,
CrazyCam

 

In aus.motorcycles on Fri, 02 Nov 2007 09:32:43 +1100

<counts references. 3. Good! Theo's law still on track>

And the Norge. No speedo cable, it's all electronic. Although since
I've been riding the T with the pushie speedo for so long, when I
passed a digital readout on the City West Link saying "you are doing
67kmh" I was disappointed that I couldn't work out whether the speedo
was accurate....

Zebee

 

Agreed. The XX speedo reads 8.5% over but the odometer only reads 2%
over, so calibrating the speedo from the odometer will still read 6.5%
out.

Nev..

 

The result is only as good as the person who calibrates it. You could
make a complete dog's breakfast of it.

Nev..

 

The digital speedo on my z1000 over-reads by about 4%, about the same
as my non-digital ZX9

 

GPS can only measure once per second, point to point, and has +/- 3M
potential error. Super-accurate? The faster you go, the more accurate
it gets, but I doubt you'd be getting near +/- .1kph accuracy at
anything less than flat out down Gardner Straight.

Why? Hasn't gaffer tape been invented yet?

Nev..

 

Ah, now we are sneaking up on what I wanted to know.

Firstly, the mere fact that people build "fixer" boxes implies that the
electronic speedos don't, as standard, have an adjustment/calibration
option.

Secondly, the fact that folk buy these boxes implies that the standard
speedos aren't super accurate.

So a Z1000 is out by 4%, but at what speed?

Old style speedos could often be fairly close at 60 and 80 and start
being a bit optimistic as the speed went up.

In their calibration instructions, the makes of the Yellow Box quote a
difference of about 2% from new thick tyre to old worn tyre.

They also warn of a 1 to 2 % error due to "growth" of tyre, at maximum
speed of sportsbikes, and a tyre "slippage" error of between 2 to 10 %
at full power.

From this last comment, I infer that many of the electronic speedo
feeds are sourced from the rear wheel.

The more I think about this, the better the deal seems to get a pushy
trip computer anyway.

regards,
CrazyCam

 

In aus.motorcycles on Fri, 02 Nov 2007 14:43:52 +1100

As long as you can light it from the bike lighting system, or power it
from the bike, or don't care about changing batteries often.

I chose option A, it looked daggy but did the job.

Zebee

 

I seem to get 2 to 2 and a half years per batter set on the trip
computers, which I find acceptable, given they do other stuff that I
want done. Clock function being the main one, since none of the four
bikes have decadent things like clocks built in.

Lighting isn't a problem, since I try and avoid too much dark riding,
and, anyway, once you have figured out how much out the standard speedo
is, mentally fixing the number in the dark isn't too hard.

I only have the one bike (Z50) where the trip computer is the only
speedo, but it has got a rev counter, which is lit up, which is, I
believe, adequate for legal requirements.

regards,
CrazyCam

 

around 110kph if I recall correctly

Some have gear speedos

 

I found the speedo error on my CBR1100XX and previous bike the ZX12R to
both be linear. The speedohealer actually comes with a built in program
to allow you to determine whether you speedo error is a constant
percentage, or not, which verified my personal estimate of a linear 8.5%
error at all speeds.

Nev..