The beemer final has a working Speedo again

I've finally got the beemer's speedo to work again.

Spent ages cleaning all of the contacts within the speedo unit,
cleaned the connections on the way down to the sensor, cleaned the
sensor (after shearing the bolt holding the sensor - wasn't even
being hand-fisted) When I had the unit open I found that someone had
"repaired" it before. By attaching extra wires and bypassing the
flexible circuit board thingy and stuffing a couple solder joints.
Besides the solder, the other problem was, they didn't bypass the the
dirty contacts going into the speedo cluster.

Put it all back together and suprise suprise ..... it still didn't
work. The only difference I noticed the needle fibrating slightly
while the wheel was slowly rotating. the needle became still when the
wheel sped up. After a little experiment ....... in particular,
swapping the polarity of the sensor and the speedo suddenly came back
into life

I think during the process of fixing the speedo, I stuffed up (well
duh). While fault finding, I replaced the plugs going into the speedo
and "somehow" put the plugs into the wrong spots ..... either way, I
finally have a better speedo then the bicycle speedo I have fitted as
a stop gap.
__


Cheers
The Happy Drunk
K100RT

 

Congratulations!
I fully appreciate the satisfaction of getting something old and battered
working again.
Not in the same league but I finally found the intermittent open-cct that
was making my left headlight run dull (both beams in series).
Now I might be able to see the roos on BOTH sides of the highway!

 

I fixed the trigger switch on my electric lawnmower (the plastic pivot-
post had snapped off)...


BTH

 

Surely they are wired in parallel. In series each headlight would only have
6 volts across the filament and any dodgy connection would affect both.
Also an intermittent open cct should cause the light to go out altogether
not run dull. This would be a high resistance connection. I know you cant
get a higher resistance than an open cct but my point remains...high
resistance equals dull lights, open cct equals no lights.

Years of experiance with bevel drive Ducatis' have made me a reasonably
competent MC electrician

Capt. A. L.

 

I didn't say both headlights in series!
No the earth on the left was the open-cct so on low beam the 12v was running
through the low filament and then back through the high filament to the
right high filament and then to the right earth.
On high beam it'd run high-> low to other low to earth.
So you'd always have one bright (and one dull filament that you couldn't
see) on one side and two dull on the other side.
You see the same thing on cars a fair bit.

 

Ok I see now that makes perfect sense
Very good deduction work there

Capt. A. L.

 

[embarrassed face] I ... errr.... pulled the connector and the wire fell off
the back......

 

Falcon tail-lights were like that for a long time.

Theo

 

I love seeing the number of well travelled much loved bikes with inexpensive
push bike speedo's on them (Moike?).

If you can be bothered to get fussed about entering the exact circumference
of the tyre they give you a surprising amount of useful and accurate
information for a small investment in time and cost.

The whizzz bangery on the lcd screen of the trump on the other hand requires
the finding and re-reading of The Manual, as no human brain can remember
such weird button sequences.

Oh for simple things that work ...

 

You'd already checked all the others? That's Science !

Nev..
'07 XB12X
'08 DL1000K8

 

Aye, I am seriously considering fitting a pushie trip-computer to my
Triumph.

I've fitted them to most of my bikes for the last while, and had thought
the Triumph wouldn't need one, but, as you say,Andrew, it's a
complicated dash on the modern Trumpies.

regards,
CrazyCam

 

Finding a bike computer that supports over 99.9kph can be a battle.

Cheap and large digits, look for a T9 Tigra...supports 199.9 kph. The
manual is actually comprehensible too.

Under $20, just guestimate the wheel diam and zero in with a GPS.

 

GPS? Is that some sort of new-fangled tape-measure like device
for measuring wheel diameter?


GB

 

Previously, I have used BC Sigmas quite successfully.

I only once had a problem with an el-cheapo trip computer, CatEye, on
the Z50, where, because of the small wheels, it would overwhelm the
processors counting speed. It worked upto about 75 kph then started
showing strange patterns on the display. The Sigma was quite happy up to
over 210 kph on the Hornet.

Guesstimate? A bit of chalk, three minutes and a tape measure to get an
accurate rolling diameter. How hard is that?

Zeroing in (or out) error by GPS isn't actually that easy, since a GPS
reading of speed is only accurate at a constant speed in a straight line.

I have done it a few times, but chalk and a tape work much better.

regards,
CrazyCam

 

I had a Sigma too but no matter how many times I ran a tape-measure around
the front wheel or measured out a rotation on the concrete I couldn't get it
exactly right.
Once I took it out to one of those speedo-measuring signposts on the highway
and set it it was perfect though.

 

The Sigma Sport (Don't get excited G-S) is claimed to show 300kph, but
will display speeds in excess of that.
http://www.thisstupidurl.com/sigma1.jpg

Mount the magnets and sensor close to the rim rather than the hub.

Harder than it sounds. If you're pushing the bike along unladen for a
couple of wheel revolutions really isn't an accurate way to replicate
the rolling diameter of the tyre under normal load. You'll probably
need to drop the tyres down to 10psi, or do the measurements with a
rider on the bike.

Many GPS units will have a top speed memory. Most bicycle computers
have a top speed memory. All you need to do is ride in a straight line,
no need to monitor the actual speed you're riding at. Accellerate
slowly, you need to hold the top speed for at least 1 second before the
GPS will get an accurate speed reading. Then you stop, check both top
speeds and make whatever adjustment is necessary to get the bicycle
computer to register the same as the GPS. Yes, there is a requirement
that the top speed be achieved in a straight line. That shouldn't be
too hard to arrange.

Nev..
'07 XB12X
'08 DL1000K8

 

Gosh, and there I was thinking a GPS was some kind of new-fangled Kwaka
sports model or something <snigger>

betty <running>

 

1. What's chalk? 2. What's a tape measure and where do I stick it?

3. Is it really a challenge going in a straightline at a constant
speed??

As already mentioned, tyre diameter varies with speed. However,
practically, the effect is minimal for the tolerances required here.

Alternative (and IMHO...assuming RTA have an accurate "tape measure"),
go find the 5 km speedometer test runs (Hume Highway south of
Campbelltown or F3 freeway on way to Newcastle).

Set the digital trip meter to zero and compare after traversing the
5km/5000 metres. The bike speedo prob has more sig digits for the trip
function than the odometer function.

But again, for all practical purposes, calibrating with a GPS device
(eg run Sports Chrono on a suitable Nokia phone with external or
internal GPS), whilst riding in a straightline at constant speed
shouldn't be too taxing for most post-Learner riders

 

and first one to ask which lane to use and whether inside or outside
on curves is the Designated Daily Smart ass.

 

alx wrote:

Well, I have chalk and tape measure in my garage.
I also have a nice bit of quiet, dead end road, right outside my house.

Recalibrating a Sigma is all of about three minutes for me.

Depends. Have you ever tried it riding a Z50 Honda?

<puzzled look> You are suggesting a two hour round trip for me to
either of those options, as against three minutes, right out side my
house? ...and the freeway isn't too flash an idea for a Z50, either.

Aye, right.

BTW, just so as you don't get the wrong impression, back in the early
'90s, I was using a Sony Pyxis (IPS-360) to calibrate the speedo on my
BMW, and I do, occasionally, cross check speedo against GPS, if I happen
to be carrying a GPS on the bike at the time, but it isn't the preferred
method of setting a pushie trip computer.

regards,
CrazyCam