Cleaning and lubing speedometer

[Rick65Cat]

I know theres an article in one of Basscliff's links where it shows a speedo or tach being cut open. Is this the ONLY way to get into the gears *inside* the speedometer?
I know with stock sprockets my `78 1000 should turn about 3700(ish) rpm at an (indicated) 100 Kph. I have stock gearing and it turns between 4000 and 4300. (Thinking the tach is accurate but the speedo is dragging)
I've already lubed the speedo cable as the needle was jumping back and forth about 30 Kph at anything up to hiway speeds. That smoothed it out until I reach hiway speeds. It still bounces around a bit anything over 100 Kph.
I'm wondering if I cleaned and re-lubed the gear assembly inside the speedo housing if it would A) free it up and B) stop the bouncing needle.
Oh, I also tried to take the gear drive on the wheel apart but I didn't have C-clip pliers and it did appear to have fairly fresh grease oozing out.

Thoughts? Advice?

[Nessism]

My advise is live with it. There is little that can be done other than keeping the cable lubed up.

Oh, and there are tons of threads on how to get inside the gauges. The search function will turn up all the particulars. Even when you get inside you can't fix the issues you note though.

[hampshirehog]

I've had a lot of success in sorting the problems you've got. Open the speedo up and spray furniture polish on the moving parts - you'll see where to spray once you've opened it up.

[posplayr]

I've had a lot of success in sorting the problems you've got. Open the speedo up and spray furniture polish on the moving parts - you'll see where to spray once you've opened it up.

How long did the clean up last? It seems that dirt must be able to collect inside the guage on the spring mechanism and it starts to move irregularly.

We used to use furniture polish on the rods of Fuzzball tables be cause it kept them slick but would not gum up like an oil might. Good idea.

I have a guage open right here on the desk and might also try to put a piece of shrink tubing over the mechanism to block dirt from getting it. There are places on line where you can buy large pieces of shrink tubing by the foot.

[Nessism]

The gears inside the speedometer are for the odometer, and don't have anything to do with the speedometer function. You can lube them but I don't see how that's going to stop the needle from oscillating nor effect accuracy. The question is how to renew the damping mechanism?

[posplayr]

The gears inside the speedometer are for the odometer, and don't have anything to do with the speedometer function. You can lube them but I don't see how that's going to stop the needle from oscillating nor effect accuracy. The question is how to renew the damping mechanism?

Ed,
Sorry I'm thinking about a Tach. I bought an NOS tach a while back and within 6 months it was bouncing. I have a few older models that have gone through various phases of function. I use heavy wheel bearing grease in my cables and have always replaced with new so not much more fruit likely from that tree.

Have to agree I have been ponding how to add dampening to the tach and it is not obvious without trying to seal it in oil.


Just had an idea, it is possible just not sure it is feasible. The Tach has this magnetic housing that drives the spring. If a rubber band could be used as a coupler to a small box that had an impeller in an oil bath might provide damping. Any idea what could be used from the damping box? It would need to be about 1/2"x1/2"


OK Another idea that might work.

1.) Clean out the Tach mechanism with furniture spray
2.) Carefully add gear grease to the spring mechanism. Just enough to get provide damping as the spring is twisted. Probably stop the big swings.

[hampshirehog]

The gears inside the speedometer are for the odometer, and don't have anything to do with the speedometer function. You can lube them but I don't see how that's going to stop the needle from oscillating nor effect accuracy. The question is how to renew the damping mechanism?

You're right Ed about the gears. And I haven't figured out how the polish trick works, but it does.

My best guess is that where the speedo internal shaft passes through the thing that looks like a top hat just behind the dial is where the problem lies. I reckon this area just dries out - I've convinced myself that if you spin the bowl and feel very carefully you can feel a lack of smoothness. If you pop the bowl up and down very gently, so that the needle lifts away from the dial face a tiny bit, maybe 1mm, you also get that very slight sense of a dryness. Give things a squirt of Mr Sheen, Sainsburys Lavender or whatever the lady has under the sink and things move smoother.

Here's a tach that once bounced around like a drunken break dancer afterwards - bench test with a drill.

[davidduarte]

snip

I've already lubed the speedo cable as the needle was jumping back and forth about 30 Kph at anything up to hiway speeds. That smoothed it out until I reach hiway speeds. It still bounces around a bit anything over 100 Kph.
I'm wondering if I cleaned and re-lubed the gear assembly inside the speedo housing if it would A) free it up and B) stop the bouncing needle.
Oh, I also tried to take the gear drive on the wheel apart but I didn't have C-clip pliers and it did appear to have fairly fresh grease oozing out.

Thoughts? Advice?

Over the years, I've had the bouncing speedo needle problem a few times on different bikes, most recently yesterday on I-495 in Mass. I was going 65-70 mph, and the speedo was bouncing around. Usually, lubing the cable takes care of this problem. Later on, when I stopped for gas, the odometer read 248, the 100 place digit quite often trips prematurely, I knew it should read 148. I checked my GPS, and which usually reads 1 to 3 more miles than the odometer, and it read 131! At some point I'll have to get in there with the furniture polish.

[Ruarymac]

Bouncing Speedo Needle fixed

Hi all,
I was reading your thread on bouncing needles. I too had a speedo on my GS1000G that would bounce from 100Kph up to 130Kph when I was cruising at approximately 100Kph. I tried everything I could think off including cleaning and lubing cables etc.

This is how I thought about it.

The speedo works by spinning a magnetic field past the bowl which is attached to the needle. The circular spring provides the tension to hold it steady against a constant magnetic field. I found that the bowl and therefore the needle could move back and forth a millimeter or so. The problem with that I thought is that moving the bowl away will lessen the effect of the magnetic field on the bowl. If the bowl is able to move in and out as it pleases then accuracy will be effected randomly. I figured if I stopped it moving in and out then may be it would be steady. I found if you remove the needle there is a screw mechanism that acts like a bush. I tightened this slightly so as not to restrict the circular movement. I put it all back together and it was steady as Eyres Rock. The speedo was now out by 30Kph so I had to open it again. At 100Kph it read 130Kph. I held the bowl so the needle sat on 130Kph and marked it with a pen. Then I pulled the needle off and turned it back to the 100Kph mark and pushed it back on. It has been accurate and steady ever since.

I hope this help you.

Regards
Ruarymac

[davidduarte]

in my internet travels, I found this shop:

no idea on prices etc. If there's one shop like this, there's bound to be more.

http://www.joellevinecompany.com/custompage.asp?pg=velosolex&parts

[Ruarymac]

Needle adjustment

Sorry, I forgot to mention that the dial has to come off to get to the adjustment screw. Don't forget to hold the mechanism firm with the needle in a known position and put mark the bowl and a corresponding mark on the frame before yo take off the needle. This way you will not upset the accuracy of you speedo. Once have have tightened the adjustment put the dial back on and then push the needle back on once you have lined up the marks you made previously.

Regards
Ruarymac