Speedometer not showing correct speed after restoration

Begonnen von tanger911, 17 Februar 2017, 23:52:15

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tanger911

Hello, ever since I bought my R26 a few months ago, the speedometer didn't work, it just bounced around, so I had it restored.

This is the correct speedometer with a 1,0 W value but it is now reading much faster than I'm actually going, showing 50+ when actually doing 40 for example.

The restorer swears he put the right gear in the speedometer, so I'm guessing I probably have an incorrect gear ratio somewhere (maybe geared for a sidecar?).

How can I find out if I have the correct gear ratio and if not how do I install a correct one?

Thank you

tanger911



Kurt in S.A.

What final drive ratio do you have?  For the W 1.0 speedometer, the rear ratio should be 25:6.  Other rear drive ratios (typically) are 27:6 and 27:8 (probably with sidecar, though).

Kurt
Kurt in S.A.

tanger911

Thanks Kurt,

I have a 25/6 (per the stamp on the cover next to the drive shaft) and I'm using an (almost) correct size tire 3.5x18 for an R26

Could the final drive ratio be different from what the stamp says?


Kurt in S.A.

What you can do is actually count the number of turns of the transmission output relative to the turns of the rear wheel so you can confirm the actual final drive ratio.

The number 1.0 means that the cable will turn 1000 times per kilometer...this is something else you can check.  If my math is right, the cable will turn once per meter or 10 times per 10 meters.  Draw lines on the ground for a given distance, put a paper clip on the end of the cable, and count the number of turns.  That will let you know if the cable turns matches the speedo.

Kurt
Kurt in S.A.

tanger911


Borgward

you should check if it shows wrong or correct distance (i.e. drive  e.g. 20 mls and see what distance your speedometer shows). Maybe you/your restorer have only to adjust the tension of the spring of the needle

rolf

#6
"putting the right gear"...the gear is only for the distance ....so if you ride 25 km...it should show 25 km more ....they are naturally different for the different types of models....a W 1,0 needs another gear as for an W 1,2.
They have otherwise NOTHING to do with the indicate(?) of speed. this would be adjusted with the strength of the magnetism (Borgward, not with tension of the spring) inside the speedometer.
1. check your really transmission (as  said before, 25/6= 25 turns of the little gearwheel produces 6 turns of the wheel, OR OTHERWISE: 1 turn with the wheel should produce 4,16 [25:6=4,16] (roundabout a little more than 4) turns of the little gearwheel, easy to check.

2. if you have the right  transmission....your restorer has make a mistake OR(!) he can't  regulate the magnetism ....therefor he needs a special electric tool ( to increase or reduce the magnetism).
3. if you has another transmission....pay again ;D
Rolf

rolf

Forgotten:
"Could the final drive ratio be different from what the stamp says?"
yes, of course....if someone put another gearwheels in the housing...the housing is the same....25/6 ...or 26/5...or 27/6

tanger911

Thanks, I will take it for a ride and compare to the phone GPS and see if the distance travelled is correct or not.

That seems to be the easiest way of telling whether it is the needle that needs adjusting or if the drive ratio or the instrument are not what they say that are.

If that doesn't clarify it I will check the turn ratio. However please explain what you mean by the little gearwheel, where is that little gearwheel (please excuse my ignorance)?

Thank you again

4Taktix

The little Gearwheel is part of the counter within the speedo. This wheel determines the Ratio. (imprinted on the faceplate)
But nevertheless the gearwheel could have been exchanged with a different one in the past, no matter what the faceplate tells.
Regards,
Sascha
Think outside the box !

rolf

Excuse my pidgin english,
I mean with the "little" gear wheel the pevel pinion....the rear axle gear box (?....not the normal  4 speed gear box)....this thing with the ratio 25/6....there you have 2 gear wheels....1 with big diameter (towards the tire)....and 1 with a little diameter (towards the gear box)....the second was my "little" gear wheel ;D

"That seems to be the easiest way of telling whether it is the needle that needs adjusting or if the drive ratio or the instrument are not what they say that are."
No...what should be the defference of a "wrong" ratio or a bad Speedometer....both shows incorrecct distance
For sure (for me): your speedo shows too much distance or speed?

Sasacha, ich meinte das Ritzel

tanger911

Thank you Rolf,

I will check and let you know. It might be a few weeks because I'm leaving on a few trips that will leave me without weekends at home

Henry

Borgward

Zitat von: rolf am 18 Februar 2017, 09:33:34
... this would be adjusted with the strength of the magnetism (Borgward, not with tension of the spring) inside the speedometer.
For explanation:
the rotating magnets inside the speedometer produce tubulent flows in a bubble cap that holds the speed needle. In order to prevent this cap (and therefore the needle) to spin around and around a return spring produces a counter torque. The spring tension must fit to the magnetic force. If the spring is too weak the indicated speed will be too high and vice versa. The final calibration is done by the spring tension, Rolf  :)

Assuming that your transmission and the speedometer fit (to be checked by comparing indicated distances wit e.g. GPS)
What could have happened:
- at restoration the return spring was dismounted and reassembled, but not with the right tension (maybe because the restorer calibrated it with a wrong transmission in mind or he just forgot to do it)
- your restorer remagnetized your speedometer (professional speedometer restorers can do it with a special tool - as Rolf already mentioned) but did not recalibrate it correctly with a higher spring tension

just my 2 cents
Borgward

rolf

Borgward....lass uns dazu mal ein eigenes Thema aufmachen....1. Deutsch...2. verwirrt es unseren Texaner nicht.

rolf

Tanger:
your speedo shows too much distance (km) or speed (km/h)?

tanger911

I know for sure it shows too much speed. I have not been able to check the distance since I am travelling and away from the R26, and last week I didn't pay attention to the distance, just the speed. I will check the distance in a few weeks when I get back.

Rolf, mein Deutsch ist nicht so gut aber ich verstehe fast alles.

But it is much easier to write in English. Don't worry Borgward I won't be too confused.

Vielen Dank

Henry


rolf

"mein Deutsch ist nicht so gut aber ich verstehe fast alles."

Like me ;)

Borgward

Rolf don't worry, I like you ;D

btw. could it be a mixing up between mph and km/h?
(reminds me on NASA smashing their Mars Climate Orbiter on Mars several years ago...) :D

tanger911

Zitat von: Borgward am 20 Februar 2017, 10:05:46
Rolf don't worry, I like you ;D

btw. could it be a mixing up between mph and km/h?
(reminds me on NASA smashing their Mars Climate Orbiter on Mars several years ago...) :D

No, no mix up for sure, this is hm/h.

Thanks

rolf

#19
H/h?....hektopascal/h? ;D

berndr253

Leben und Leben lassen

rolf


tanger911


tanger911

Ok, so I just got back from a short ride with my phone acting as a GPS speedometer.

It turns out the distance (odometer) measures 100% correct, but the speedometer is almost 50% off! When going 40km/h it reads 60km/h.

So I guess the problem as someone mentioned has to do with a poor job calibrating the needle...

Any suggestions as to whom I could send another speedometer I have for restoration?

Thanks

Borgward

if you don't mind shipping to Germany you could try one oft these:

http://www.ka-ja-tacho.de/site.php?view=kontakt

or

http://www.horex.info/


the two have a very good reputation in this forum



tanger911

Zitat von: Borgward am 06 März 2017, 18:18:10
if you don't mind shipping to Germany you could try one oft these:

http://www.ka-ja-tacho.de/site.php?view=kontakt

or

http://www.horex.info/


the two have a very good reputation in this forum

Thank you, it would be much easier for me to ship to the United States, but if I can't find anyone there I would give the ones in Germany a try.

Kurt in S.A.

I mentioned in the other thread several places in the US that do this work.

- Overseas Speedometer in Austin TX
- North Hollywood Speedometer in California
- Palo Alto Speedometer in California

These are all "big" business places. A guy who does this out of his house and gets many kudos is Terry Vrla:
- terryvrla at hotmail dot com in Hillsboro, OR

Kurt
Kurt in S.A.

tanger911

Zitat von: Kurt in S.A. am 06 März 2017, 21:41:17
I mentioned in the other thread several places in the US that do this work.

- Overseas Speedometer in Austin TX
- North Hollywood Speedometer in California
- Palo Alto Speedometer in California

These are all "big" business places. A guy who does this out of his house and gets many kudos is Terry Vrla:
- terryvrla at hotmail dot com in Hillsboro, OR

Kurt

Thanks, Palo Alto and North Hollywood I know and have dealt with them in the past. Very good but sometimes slow and on the pricy side.

Will reach out to Terry

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