Bike Computers

[Steve Fleming]

Bike computers to fit to a Seven. I know it's been done, just need some info.

Halfords have a 12 function cordless but apparently the top speed that it will

accept is 63 mph. So no good for a Seven.

 

A local bike shop has a model that will accept a top speed of 183 mph (just

what sort of bikers are there out there?!), but the sender cannot be farther

than 45 cms from the unit and with not too much machinery in between. So,

attachment to the front wheel is out of the question, and the rear wheel is not

suitable because of wheelspin.

 

Anybody out there who has fitted one? And if so what model, fitting problems if

any, and does it work?

[Nick]

The best place to start is Jason Brown's site. Sigma have recently revised their range; the BC1200 was the one to have and is still available; I don't know what has replaced it, though I was told a back-lit one is now available.

 

It's possible to hide all the wires, so need need to go for the wireless kit.

 

Nick

[SLR No.77]

I use a Sigma BC800 which works brilliant. Make sure you go for the corded type ie. not the wireless, then just extend the wire as necessary. The BC800 costs about £18 (Dave Hinde Cycles, Northwich, Cheshire). One advantage of the Sigma is the sensor being attached by a heavy duty rubber band, making it easy to reposition for different size wheels. I started with the BC1200 but found it had too many features - only any use on a bicycle (where it is now).

 

I've checked mine for accuracy with a sat-nav system, and its spot on. Better than Caterhams attempt at speedo accuracy.

 

Stu.

 

[mike ashurst]

I used a BC1200, and yes it has got to many features, but it does work really well. I also looked at Jason Brown's site - www.strangely.org - where he discusses the topic in great detail with some useful pics, and links to other sites.

 

Mike

[Steve Fleming]

Thanks to all for replies.

Certainly Jason's page explains it all and is very useful. Cordless is definitely out. Just need to decide how and where to stick it on the dashboard. I guess the R500 boys don't know what we're talking about, what with their Stack stuff!

 

Steve

[John Richens]

Steve,....we just have lots of pretty coloured lights and warp factor no.s

luv R500OLE wink.gif

[Pierre Gillet]

What drives exactly the need for a replacement?

I like the very regular one which may be optimistic, would fear to be disapointed by the actual speed.

 

Pierre

[VC]

Why not get one of the bike computers which have heart rate monitors inbuilt? Great for attaching to passengers. You can calibrate the vehicle speed to their heart rate!

[Jason Plato]

Anyone know wich make of bike computer can measure 0 - 60 etc ????? , I know they use them in sprint cycling to measure how quickley how their little legs whizz around from a standing start .

 

dave

[mike ashurst]

Slight alteration to the way Jason fits his bike computer.

 

Instead of fitting the sensor to the wing stay, fit it to the front upright, on

the vertical bit just below the upper wishbone joint. Then glue the magnet to the

back of the disk on the inset section just inside of the braking surface. Check

that it will clear the calipers, mine is a 96 dedion K-series and it works just

fine.

 

It doesn't need any more wire, and the big advantage is that you don't have to

worry about changing wheels. I've just gone to 16's for road use, and there was

no way I could position the sensor so that it worked for both sizes. Plus the

magnet is'nt glued to the wheel so you can "rotate" your wheels round the car

without fitting extra magnets.

 

Dave, I'm a cyclist as well but have never come across such a device, but if you look at this URL:-

 

http://www.race-technology.com/WebPage/Products/Accelerometer/Main_accelerometer.htm

 

you'll find a handy piece of kit that will do what you want, and not too expensive!

 

Mike

[Pierre Gillet]

Mike et al.

I am envisaging now adding a bike computer since the French regulations in terms of excess speed are getting more severe.I need an instrument more accurate than the standard Caterham one.

You wrote that you glued the magnet on the disk. Which kind of glue did you use? The magnet that I plan to use is in a kind of plastic casing. I do not know if the plastic and the glue will stand the temperature reached by the disk under braking. Did you experienced any problem relative to temperature?

The wire will probably be too short. Is it acceptable to solder an extra length of wire?

And finally, how can I fix the computer on the dash without having to drill a hole?

Your experience would be very much appreciated.

Cheers,

 

 

 

Pierre

[PACR]

I've bought a Sigma BC800 but haven't got round to fitting it yet. Checked Jasons site and the idea of fitting it to the prop shaft is an appealing one - can rotate wheels around, doesn't look odd, don't need to worry about a magnet jamming my brakes when the glue lets go at a few hundred degrees. There wasn't any detail about where it was fitted. I was thinking about on the gearbox end as it's nearer the dash... Has anyone on the list tried this method yet?

 

Pierre, the holder for the computer allows it to sit nicely on a bikes rounded handlebars. It can slide out to stop people nicking it when you leave your bike parked. However the holder for the computer I got looks crap. I'm going to use it whilst I check evrything works then if I'm happy solder the wires straight to the contacts on the back, stick velco on the back and a little bit to the dash somewhere where it's in my line of sight and a bit under the scuttle out of view. So when I want the car to look normal (well as normal as a Seven can ever be) I'll just stick it out of sight. Of course this works well in theory.....

 

Piers

[SLR No.77]

With the sigma 800, the rear body section is identical size to the switch cut-outs in the dashboard. If there's one that you don't use (eg. heater!!!) make up some contact pieces (kitchen foil works well) then glue in the unit.

 

I is also possible to cut down the mount, drill it to accept a couple of thin countersunk bolts, eg.M3, then bolt it to anything, eg. triangle at end of dashboard.

 

The wire can be easily extended to reach the front wheel with no problems. Not +/- dependent either, so fine for most of us.

 

 

 

[Mat Norris]

I have fitted a raleigh pro 12 which can inadvertantly measure 0-60. Basically you set a time of 5 seconds and then blast, as the computer starts only when the wheels begin to turn. The computer records the maximum speed reached within the five seconds! You can also measure a standing quater mile properly.

Initially I mounted the sensor on the front wheel but it required regular adjustment and looked abit dodgy. I have looked at mounting it on the propshaft, but in order to get the correct speed I have to enter a wheel circumfrence 3.61 (diff ratio)times less than the actual size. The problem is that this value falls below the minimum settable value of 1000mm. If anyone has any ideas I would appreciate it! Otherwise I think I will mount it on the axle with the sensor mounted on the rear drum, because the drums are next to useless so shouldn't get too hot!

[Pierre Gillet]

Thanks you all for your inputs. I understand that soldering a longer wire should not be a problem. Location of the sensor and magnet on the car I understand is not so obvious as each method has its pros and cons. For a rear location I figure that it is not so easy to get the wires from the rear to the dash through the cockpit in a tidy and invisible manner. On the screen, the issue of preventing the computer from being nicked is worth taking into consideration too.

OK, another interesting work during week end!

 

Pierre

[aideen]

Haven't looked at this in detail but:

 

There's also a "Sigma Targa" which claims to have a reinforced TI-Metal casing and an extra thick wiring harness. See:

http://www.ishop.co.uk/ishop/22/shopscr223.html

 

[Mcalvert]

I don't suppose that any of these computers have timing facilities that would allow you to get an estimate of lap times are there?

[Nick]

The Sigma BC1200 always shows current speed (up to 183 mph); it can also display:

- time

- distance logs up to 99,999 km or miles

- trip distance

- travelling time with auto stop/start function (ie it stops recording the time when the vehicle stops)

- max speed

- average speed

- comparison between current and average speed

- 2 odometer logs: handy for different sized wheels, though I use one to show road miles, the other to show track miles.

- total distance (adds the 2 logs)

- total travelling time

 

So, travelling time is the closest that comes to it on the BC1200, though the BC1400 does more. There again, timing's a no-no at trackdays and the use of this sort of thing could result in a year or two of insurance sanctions of some sort.

[Pierre Gillet]

Yep, this is the one I have. A Sigma Sport Targa with the titanium casing. Matches very well my SS Motolita wheel and ali gear level knob ( James Whiting).

Just visited Jason's site. It's great.

 

Pierre

[Pierre Gillet]

Yep, this is the one I have. A Sigma Sport Targa with the titanium casing. Matches very well my SS Motolita wheel and ali gear level knob ( James Whiting).

Just visited Jason's site. It's great.

 

Pierre

[Pierre Gillet]

Still trying to find the right place for the computer on the dash. Have thought to install it just above the rear mirror.

Question: Is the sigma Sport really waterproof?

 

Pierre

[Pierre Gillet]

Hi Nick!

I visited again your site "Rhubarb" and found the neat installation you did. How is the copper bracket fixed to the scuttle? Did you glue it, or it just stays in place because of its length?

 

Cheers,

 

 

Pierre

[Nick]

Pierre - the copper bracket stays in place because of its shape - try experimenting with a bit of plastic plumbing tubing, with a diameter of about 2cm. Cut a bit about 3 cm long. Make a lenghtways cut to 'open up the tube'. Bend one edge back, making a flat - so that from 'end on' the shape is like a question mark. The flat bit goes between the scuttle and dash. The curved bit curves around the scuttle, and the computer bracket attaches to that.

 

For added stability, a bit of glue can be used to hold the copper tube in place.

 

As I say, its easier to experiment with plastic tubing, then get the saw and file out and attack a bit of copper tubing.

 

Please let me know if you want a better description of what I've done - though note that I'll be out most of this weekend.

 

All the best

Nick

[Pierre Gillet]

Thank you Nick for the very precise thumbsup.gif fabrication instructions. This week end is dedicated to the computerbiggrin.gif .

Will keep you posted!

Best regards,

 

 

Pierre

[Pierre Gillet]

I have almost completed the installation of the my Sigma Sport bike computer. I have installed the bracket just above the rear mirror using a small hinge. One of the "wing" of the hinge is fixed on the windscreen frame using the black rubber double face which was originally at the back of the bracket (it is easy to remove and use again). The other wing of the hinge is fixed to the upper horizontal part of the bracket using a small screw. The electric wire " follows" the winscreen frame. In fact, I have splitted the double wire into two single conductor wires. Each of the wire follows the frame, one by the right, the other by the left. The wires go into the cockpit through the holes of the windscreen heating system wires.

The magnet is epoxy glued to the left fore disc very close to the hub.I used some "ali cold welding : resin into which one adds ali powder as a catalysor and load. It can stand pretty high temperatures.

The sensor is fixed to the vertical part of the upright.

The system seems to work well.

I have dismantled the bracket waiting to fix it next week on the new windscreen assembly that I have ordered from caterham.

 

 

Pierre