Speedo Error

Got the GPS bike mount today so went out for a ride to compare the GPS speed
against the speedo on the 2001 Bandit 1200.

At a speedo reading of 100 the GPS showed 89.9. I thought the days of 10%
speedo errors were decades ago! (The gearing is standard).

The cage (Peugeot 406) is a litle better at about 5%. I had to hire a car
(Vauxhall Vectra) for business a few weeks ago and that seemed to be about
3% out.

Mark

 

To add some more figures, the new pig ugly Megane reads spot on right
through to 100, my SO KA is at least 10% all the way through the range,
the T595 is around 8% at 30 and gets better as it gets faster, and a sigma
thingy (paging Lozzo) was around 5% out

 

IME all vehicles will read over,infact it may be the law ....

Also cable and cog systems (which I think the bindit has) , IMO, are more
innacurate than the electronic ones one the cars you mentioned.

FWIW, my 406 showed 2mph under at 80/90/100/110 mph

 

Ovenpaa says...

My Sigma is fitted to a SOHonda250. It's only there to satisfy the MOT
man.

 

I think 5% is good (1) and predicatably the electronic speedos are the
most accurate

(1) £9.99 - yup that will do the 'mini beast'

 

If it's 5% inaccurate, why don't you just change the wheel
circumference that it's set to? Given how much adjustment they have
I'd be surprised if you couldn't get it bang on.

 

My AX-D read about 10% over as does my Skoda. SWMBO's Saxo is about spot
on.

The HD was under-reading by about 10% - before checking I worked on the
basis that I had to be doing 88 to do a real 80, but 88 actually turned
out to be about 97 so it was actually a lot quicker than I credited it
for.

 

If it's the law, why do they sometimes allow +10% + 2 for speed check
purposes? And how do they allow for ageing of the instrument? Or is it
only a requirement for a new vehicle?

I hope it's not a general rule 'cos the Guzzi reads low by about 8%
across much of its speed range, AFAICT.

 

I am happy with 5% as it is only to passify the MOT man, however it is
quite limited in features so I will trade up to a trailtech unit
shortly(1) It is more suited to my application, has a bigger display, is
less likely to fall off and has buttons that can be easily prodded with
gloved hands whilst on the move.

(1) it had better be acurate given the price!

 

In fact I have a feeling the MOT does not require a speedo, however the
police do.

 

It would be interesting to find out how much mine is out. When I go
through speed cameras, some cars are the same speed, some are slower and
others much quicker through them. I put this down to driver
cautiousness/recklessness but if the speedos are that far out it would
not only through into doubt one's speed, but if you were really anal
about it, your fuel consumption as well.

 

YTC#1 wrote

I am happy to take what it says on the dial.

Well not exactly happy as such, more like resigned but you know what I
mean.

 

The Japs build in the +10% error very accurately. It's to make you think your
bike can keep up with a well screwed together Norton Comnmando.

 

See, see?

You're doing it to yourself now.

 

If you can't beat 'em, join 'em.

 

I've always calibrated speedos this way (well, since I had a GPS
anyway). They're pretty much consistent ~10% high - certainly the
Sprint ST, the gixxer thou, the Volvo V70 and the Peugeot 206cc, which
between them vary from +7% to +11%, depending on speed.

Dissapointing when you realise that the indicated 175mph was actually
only 162, though.

 

**** me - did you never think of getting out of 1st gear?

 

Ace wrote

See, I am not that sort of poseur me and I quite like the adventure of
going to new places with a just a glance at the map and a few detailed
directions for the home stretch so I don't have the benefits of all this
GPS crap and so I do it different.

Lorries are good. Get behind a convoy on the M1 and it will be doing
spot on 56 miles an hour on the flat bits.

At a Standard 18 wheeler 56mph The Pacemaker could be doing pretty much
anything between 15 and 80 depending on when you happen to look at the
needle.

 

Hmmm. Joke or whoosh?

 

Try reading it again, for values of (cough) equal to 100.