Topic: CB550 Speedometer "hangs"

[hereforever23]

I've noticed a little problem with my 1975 CB550 Speedometer...it seems to be reading more or less correctly (verified with phone GPS) but when I am in city traffic I am noticing that it is sort of hanging and only slowly dropping back down to zero when I get to a stop.  This doesn't seem likely to be a cable issue but more likely some problem inside the speedometer?  Hoping someone has had a similar problem here and there is an easy fix...otherwise I guess I'll look into speedometer repair somewhere b/c I 'd like to keep the odometer reading

I see Palo alto speedometer has been recommended previously on the forum http://www.paspeedo.com/

[mono]

found it:
http://forums.sohc4.net/index.php?topic=13367.0

hmm - no, this isn't as detailed as the thread i'm thinking of --- can anyone locate that thread about rebuilding the speedo and refilling (in detail) the grease cup? 

[Dinola]

In reading the link, i see several recommendations to replace the cable.  I have the same problem - 'lagging' speedo and so I ask...
can a bad cable be detected visually?  I've disassembled, cleaned and lubed the cable.  In doing this the drive cable comes out of the housing cable and all looks well there.  I don't see how the cable, once connected to the wheel, can be not turning at the appropriate rate if the cable is in one piece.  Do looks count or can there be an unseen issue with the cable?

[hereforever23]

The 'lagging' problem is actually sort of opposite the problem described in the link.  The slowness on my speedometer is after reaching speed.  It is not lagging to reach speed but rather lagging to drop.  Lagging to reach speed to me could suggest some friction within the cable but I don't see how a cable problem could cause the speedometer to slowly drop back down.  I will try lubricating the cable and see if that helps...

[Dinola]

I don't know about the internals of the speedo but i don't think that just spraying lube into an instrument is recommended.  If lube is needed its probably in a very specific place and a specific lube, otherwise its just collecting dirty or even altering how the instrument works.  i bet alot of those parts are made to work 'dry'. 

[saxamaphone]

I have my tach apart right now.  I'm about to change the face because the original is pretty warped.

Here's a thread where I had a tach and speedo needle that would stick in various places or be sluggish.

http://forums.sohc4.net/index.php?topic=113301.msg1274973#msg1274973

If it's slow going down, there is a little spring in there under the needle and face that might not be doing it's job.  If that's the problem, I'm not sure what's involved in replacing it.  Good luck.

[wrenchmuch]

Don't mess with the spring. It is related to instrument calibration and tweaking it will cause inaccuracies in the instrument. It's more likely something in the instrument that's touching or binding. A poorly lubed cable will cause jumpy needle which can also be due to a lack of fluid in the damping pot.