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Speedo accuracy

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jonhunt
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Speedo accuracy

#1 PostAuthor: jonhunt » Wed Aug 29, 2018 9:25 pm

Since replacing the Speedo cable my Speedo has gone from optimistic to ridiculous. As I accelerate it will shoot up to 100 indicated. If it was a wear issue I’d expect to be slow not fast.

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Re: Speedo accuracy

#2 PostAuthor: deka » Wed Aug 29, 2018 9:52 pm

R u not twisting the throttle tooooo enthusiastically :D
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weaver
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Re: Speedo accuracy

#3 PostAuthor: weaver » Thu Aug 30, 2018 6:05 am

shite cable by the sounds of it :??

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warren3200gt
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Re: Speedo accuracy

#4 PostAuthor: warren3200gt » Thu Aug 30, 2018 7:49 am

either the cable inner is catching when its turning or the cable is poorly routed by the sounds of it. Speedo cable needs to be as inline as possible with no sharp bends.
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Charlie
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Re: Speedo accuracy

#5 PostAuthor: Charlie » Thu Aug 30, 2018 10:55 am

It is likely a vibration issue, given it increases to silly levels when the motor is revving hard. Check the mounting pads are good and that the mountings are not overtightened.
Why do I persist in debating with idiots ? I really should know better :)

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jonhunt
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Re: Speedo accuracy

#6 PostAuthor: jonhunt » Fri Sep 14, 2018 5:21 pm

Been trying to get to the bottom of this one. The Speedo now also doesn’t return to 0 at a standstill. If I tap it it will return, also if it’s at 0 I can make it jump up to 10 mph and stick, bike static. Seems likely the springs gone west. The replacement cable is probably a coincidence
Looks like a job for Al Marshall

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Re: Speedo accuracy

#7 PostAuthor: weaver » Fri Sep 14, 2018 7:05 pm

Remove cable turn inner by hand checking for tight spots remove inner and check condition,does inner slide freely in out of outer?

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jonhunt
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Re: Speedo accuracy

#8 PostAuthor: jonhunt » Fri Sep 14, 2018 9:08 pm

Cable is new. Checked it seems good. There’s no physical join between the needle and the drive cable it’s moved by magnetic eddy currents so even if the cable sticks the needle should fall to zero. My reasoning is as the spring holds the needle back to give the right spring if it breaks or weakens then the Speedo will be very optimistic. That’s what’s happening. Also it won’t push the needle back when the drive stops.

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Re: Speedo accuracy

#9 PostAuthor: ZedHead » Sat Sep 15, 2018 7:46 am

My guess would be lack of damping in the clock. Al Marshal is your go to man.

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alinus65
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Re: Speedo accuracy

#10 PostAuthor: alinus65 » Mon Mar 13, 2023 11:37 am

hi, I am Alessandro from Italy, owner of Z1b 900 (1975)
My speed in KPH has a needle oscillating a lot above 60 kmh. I ha been told by a specialist that it could not be repaired.
Then I bought a new speedo from Dave and I installed it.
I had to file the frame because the replica is not fitting on the original frame. Finally I managed to install it but it is very tight (tachometer can be moved by hand).
I have installed and tested but it is given much less speed (i.e. at around 100 KPH is showing 60).
I have tested the clock by connecting the cable with the drilling machine and it goes up without problems.


Could it be that the clock is too tight? (Dave is selling a frame for this clock).
Could it be that there is something wrong at the wheel hub, i .e. Gear speedometer (41059-016) or pinion speedometer (41060-012)?
Any suggestion is welcome.
Thanks in advance.

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chrisNI
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Re: Speedo accuracy

#11 PostAuthor: chrisNI » Mon Mar 13, 2023 10:33 pm

Sounds like it’s reading mph with kph on the dial :shock:

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alinus65
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Re: Speedo accuracy

#12 PostAuthor: alinus65 » Tue Mar 14, 2023 8:10 am

I had the same thought but what should I do to rectify?
ciao

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warren3200gt
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Re: Speedo accuracy

#13 PostAuthor: warren3200gt » Tue Mar 14, 2023 8:23 am

If that is the case then easiest route is to get a replacement.
For speed indication both mph and kph internals are the same only the dial face is different.
However, if that is the problem then your mileage indicators will also be wrong. The mechanism ratio for mph and kph are different.
So it's not just a case of swopping the dial face.
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alinus65
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Re: Speedo accuracy

#14 PostAuthor: alinus65 » Tue Mar 14, 2023 4:30 pm

is there anyone who wants to sell the whole case-assy speed gear (part n 41078-001).
thanks

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alinus65
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Re: Speedo accuracy

#15 PostAuthor: alinus65 » Tue Mar 21, 2023 1:33 pm

Hello,

Is the case-assy speed gear (part n 41078-001) same for miles and Kilometers?

Thanks


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