Bicycle Computer

Did a minor modification today.

I'm off to France next month and they use those new fangled kilometre thingies as opposed to the good old miles. Now, if you have a mph speedo you will see how small the kilometre markings are. Given that the French gendarmarie love to book foreigners for speeding I have been looking for ways to make knowing my kilometre speeds easier to see.

Finally chose a Sigma 509 bicycle computer. I had to extend the wiring between the sensor (that fits to the fork) and the head (the actual computer) by about 18" but as there are only two wires and all they do is send a pulsed signal everytime the magnet (attached to the wheel) passes the sensor it wasn't rocket science to solder an additional piece in line.

Didn't bother with the Sigma magnet, which is designed to fit onto a spoke on the wheel, but chose instead to glue a flat earth magnet onto the rim. I actually glued it by the valve but that was only so I could see if it was still on without having to hunt for where I had stuck it. The magnet is about ½" in diameter and less than 1/16th" thick. The sensor was tie-wrapped (zip tie over the pond) to a slightly flexible piece of metal. This metal was then placed on the two bolts on the inside of the front mudguard. Being slightly flexible allowed me to bend and form it so it sat in the correct place. It had to be with 5mm of the magnet to pick up the magnetic field.

The actual computer was fixed to the dash between the speedo and the rev counter using a strong rubber band (actual it is an 'O' ring). It slightly obscures the speedo but the speedo is clearly visible after 20 mph. As the computer can be swapped between mph and kph I can always see my speed on the computer.

Calibration was a doddle, Marked the tyre, laid a tape measure on the floor and rolled the wheel one complete revolution, read the distance anf entered that into the computer (1650 mm). But it all back together and went for a test ride using GPS to show correct speed. I adjusted the size to 1675 mm and it is accurate to within a couple of tenths of a kilometre. Close enough to keep me within the legal limits.

Next job is to fit one on my mate's CBF1000 which will be a lot easier as the wiring doesn't need to be extended.

No excuses now for those 200 euro speeding fines!

Cheers,

Thanks for great info on something that works....Sounds good to me as I can fit it even higher....I have the new Givi Airflow screen and am thinking of fitting it between the two clamps so its much closer to my line of view without having to glance down

tarmacburner2 wrote:

I'm off to France next month and they use those new fangled kilometre thingies as opposed to the good old miles.

Welcome to the 21st century. The Imperial system makes no sense and is for Luddites and Americans only :lol!:

A digression:

I was just beginning my teaching career when the Metric System was being introduced into the UK - in fact I was in the middle of my final Teaching Practice when currency changed from £sd to £ & p.

It was supposed to make everything so much easier for the children; Base 10....or is it Base 100......!

At the same time, the experts decided that children needed to learn different Bases - computers were rearing their ugly heads.

So instead of children acquiring the skills in the course of their daily learning - the Imperial system includes the use of several different bases in the same sums - we were forced to have separate 'lessons' for learning how to use different bases.
This proved difficult as learning such skills in a vacuum is far more difficult than learning them for some specific, everyday purpose.

One minor point for me as a teacher was that there was no suitably-sized unit to use when teaching young children to use a ruler for measuring; the centimetre is too small for their inexperienced fingers and the decimetre, not accepted in schools, is too big.
The inch is perfect.

Curiously, last week I had to buy a new inner-tube for my bicycle. It's an English bike with imperial measurements on the tyres.
I converted them to centimetres to buy the tube in the Belgian town in which I live.

I looked at the tubes and, lo and behold, the measurements on the box are in inches!

I think it was a French king that introduced the metric system as far as measurement is concerned. Isn't the metre supposed to be something to do with the distance from Paris to the North Pole?

Tried it on the motorway this morning and it works a treat.

Cheers,

tarmacburner2 wrote:

I think it was a French king that introduced the metric system as far as measurement is concerned. Isn't the metre supposed to be something to do with the distance from Paris to the North Pole?

Tried it on the motorway this morning and it works a treat.

Cheers,

Actually.

1 Km is one ten thousandth of the average distance from the equator to either Pole!!! This is because the Earth is an oblate spheroid!!! (Not round - more squashed at the poles!!!).

So speaketh the Ex Navigator!!!

Edited bit;

http://en.wikipedia.org/wiki/Oblate_spheroid

And there was I thinking the Earth was a geoid!
(there speaketh the pedant)

Cheers,

I don't think that Napoleon was a king.

Jon

tarmacburner2 wrote:

And there was I thinking the Earth was a geoid!
(there speaketh the pedant)

Cheers,

Whatever!! It ain't round!

Looks round from where I'm sat!

Cheers,

Kinda flat looking to me. You must go to 'Spec Savers'.

It was during the reign of Louis XVI that the system was commissioned and devised but officially adopted in France when Napoleon took over.

I was completing high school when we switched from Imperial to the Systeme Internationale (SI). At the time the only benefit I could see was that gasoline suddenly got cheaper, or so it seemed. We went from $1.25/imperial gallon to $.25/liter. How wrong I was!

Today, when I travel to the US, at least I understand the temperature, distances, and weights that they use. When Americans come here, their understanding of the metric system is rudimentary at best. I suppose one day they'll see the light........ or not.

joncallihan wrote:

I don't think that Napoleon was a king.

Jon

The pedant in me is coming out today!

Napoleon went from 'First Consul' to 'Emporer of France', but he was 'King of Italy' from 1805 to 1814.

Metric and imperial systems come together in this country when dealing with wood. The section is done in millemetres (e.g. 50 x 75) and the length is stated in feet. So you will hear someone ask for 100 ft of 75 by 1000 softwood - and to us it doesn't sound daft!
Cheers,

We Americans are FAR behind the curve on the metric system. I have worked enough internationally to realize that the metric system is quite superior.

Unfortunately it is difficult to change how people think. We have it in our heads how far 100 yards is, how far a mile is, how much an ounce weighs, etc.

At least we are not as bad as the British, who apparently still tell weight by "stone," only recently abandoned "shillings" and are bravely sticking to pounds instead of euros.

Incidentally I love the bicycle computer modification and might take a shot at that one myself, when I get my Swing back from the shop.

DuggleBogey wrote:

At least we are not as bad as the British, who apparently still tell weight by "stone," only recently abandoned "shillings" and are bravely sticking to pounds instead of euros.

Dam right. That's what makes us what we are.

Wait until we start on about 'groats' and 'hectares'!!!!!!

Then there are the nautical measurements. Nautical miles, longer than a statute mile. 'Cables' and fathoms,

Uniformity would make so many companies panic.

Easy modification to do - one thing I did do was fed the wire through the right hand vent on the sloping bit of the dashboard just above the handlebars. The wire had to be cut and an extension length soldered in so the wire was routed before it was rejoined. Remove the right hand 'cubby box' to get the wire to the front fork.

Sometime I'll take some pictures and do a 'how to'. It does give you an accurate speedo.

Cheers,

Waspie wrote:

DuggleBogey wrote:

At least we are not as bad as the British, who apparently still tell weight by "stone," only recently abandoned "shillings" and are bravely sticking to pounds instead of euros.

Dam right. That's what makes us what we are.

Wait until we start on about 'groats' and 'hectares'!!!!!!

Then there are the nautical measurements. Nautical miles, longer than a statute mile. 'Cables' and fathoms,

Uniformity would make so many companies panic.

When someone saw our volume system they were heard to exclaim 'Firkin Hell'.

Cheers,

Er, shillings went out 40 years ago!

Am I correct in thinking all denominations of US banknotes are the same colour or has that changed?

This is not an 'anti' post but why do Americans talk in pounds when describing large items - 'tons' are much easier to picture.

We say pounds when we want things to sound big, and tons when we want to make them seem smaller or stronger.

Here in the UK it's illegal to sell stuff in pounds and ounces, has been for years, and traders have been fined for selling in Imperial weight. We also buy fuel in litres, and by nature still convert it mpg.

We abandoned ''shillings" for metric currency in 1971, so is 40 years ago recent? As for the £ Sterling v the € Euro, even Germany would bin the Euro if it could. Racehorses are still traditionally sold in guineas, 21 shillings in old money terms.

We do our weight in stones and pounds, as well as kilos, we don't measure it in pounds like you do. Traditionally we enjoy pints of warm beer which isn't true, but in the US you all seem to think that's what we like

Then again you're calling one-cent coins ''pennies", what's that all about then.

I see you're from Tennessee, mention that to some Brits and they'll you all wear straw hats, checked shirts and dungarees, and you're whittling a stick on a porch somewhere, spitting streams of tobacco juice into an empty moonshine jar.

Is that 'tons' or 'tonnes'?

I have trouble with 'newton-metres', much happier with 'foot-pounds'.

I have a few florins, half-crowns, shillings, sixpences, thrupneybits, pennies, ha-pennies and farthings in a tin - for when we come out of Europe and go back to £sd. (Oh and a couple of ten bob notes and some groats as well).

Cheers,

Meldrew wrote:

I see you're from Tennessee, mention that to some Brits and they'll you all wear straw hats, checked shirts and dungarees, and you're whittling a stick on a porch somewhere, spitting streams of tobacco juice into an empty moonshine jar.

That's because we are, unless we are messing up public restrooms..

Whenever I watch BBC America my wife asks me how much a "quid" is. I tell her it's the same thing as calling dollars "bucks" but she can't seem to remember.

All American bills are the same color and shape pretty much, but that's just a practical joke on blind people that went overboard.

I managed to collect one of each pre-decimal coin, including a farthing, with the last year of minting on.

Hectares is metric, Doug - did you mean 'acres'?

Don't forget rods, poles and perches.

MikeO wrote:

Hectares is metric, Doug - did you mean 'acres'?

Don't forget rods, poles and perches.

Ha Ha - probably!!!

I don't know what I mean any more Mike. Time for bed I think!!!!

(Been caught up in cleaning my PC from some malicious gits idea of money making)

"Traditionally we enjoy pints of warm beer which isn't true, but in the US you all seem to think that's what we like" wrote Meldrew. "warm" is relative, the piss made here has to be nearly frozen to be palatable. Besides which, Lucas (the prince of darkness) has never sold a refrigerator here.

Jon