Speedo woe... r80g/s (1982)

[stuart jenkins]

Out on a nice frosty ride yesterday, when my speedo started 'dancing', then span all the way round and snapped the needle in half! must be the season for it as i've read it's happened to quite a few people recently!

The speedo cable is fairly new and spins freely... so i thought i would open her up and see what was foot. After getting the speedo rim off the innards look good condition for 82,000 miles, no worn plastic cogs, still evidence of grease, only light surface rust on the metal 'bracket' that holds everything together.

... but did find a small 'y' shaped flat piece of metal in the bottom of the casing when it was separated. Looks like it could be some sort of spacer? but where does it go?

does anyone who has had a go at taking their's apart know where it should go?


Any help much appreciated.
Stuart

 

[England-Kev]

Stuart, you might ask this guy...

http://www.advrider.com/forums/showthread.php?t=690684

 

[stuart jenkins]

Cheers.
Signed onto the Adv site and ontic got back to me, after reading his reply i really looked at all the parts and found this tell tale rust 'brass rubbing' on the underside of the speedo needle!
As everything else looks good i'm going to re-grease and oil the parts and test it.
Thanks for the heads up.
Stuart
r80g/s '82

 

[stuart jenkins]

Does anyone happen to have a spare speedo needle lurking in a dark cupboard somewhere that i could purchase? Not sure if one needle fits all, or if they were model spacific, but i'm willing to try any thing before i have to resort to tin foil, sticky back plastic, and a cardboard toilet tube in true Blue Peter (this would be in keeping with the rest of the bike though).
Cheers
Stuart

 

[stuart jenkins]

The saga continues

...Well, last week i managed to repair the speedo needle, by super-gluing the old one together! i greased the speedo needle where it goes into the magnet bush as it was dry, put the speedo back on the bike without the glass, strapped the satnav on to check whether i had put the needle back in the right place, and went for a test ride...

All the needle 'dancing' had gone and it was as smooth as when i first got her, so the dry needle seems to have been the problem, the speedo was reading the same as the satnav up to 40mph and read over by 5mph at 90, which i can live with...

Got home and re-set the glass and facia rim, put it back on the bike and found I couldn't tighten the fastening nut at the back of the speedo... Bugger!!! The threaded plastic collar sticking out the back where the speedo cable screws on had sheared off!! Apparently 'another' common occurrence with airhead speedos! The plastic perishes after time and becomes brittle.

...After a week of looking for either:
1. replacement g/s speedo (expensive/rare as hens etc)
2. A /5 speedo to use the speedo drive mechanism which is in aluminium, not brittle plastic, and can apparently be used as a direct replacement (expensive/ rare as hens etc)
I could see a pattern forming, so I decided to have it apart again and see what I could do.



... I was quite pleased, as it was my first thread cutting experience on the lathe ( hence the missing section in the middle of the thread oops! ) Oh well there was still enough for everything to bolt up nicely. I think next time I would buy a 18mm die to cut the thread but i'm an impatient bugger!

Off for a test ride!

 

[Voyager]

That's a good fix (apart from the 'missing bit')

Its always good when you can manufacture something yourself .

My lathe is so old I only have Imperial threads I keep looking at newer ones and I guess I'll have to take the plunge sometime.

Which lathe do you have ??

Bob.

 

[pete.keys]

... I was quite pleased, as it was my first thread cutting experience on the lathe ( hence the missing section in the middle of the thread oops! ) Oh well there was still enough for everything to bolt up nicely. I think next time I would buy a 18mm die to cut the thread but i'm an impatient bugger!

Off for a test ride!

Cool - very inventive.

Hope it worked ok!

 

[stuart jenkins]

Hi Bob,
I know what you mean, I was looking at an expensive fix if I couldn't do it myself, either that or totally change the front light/speedo set up but again more outlay, and I also like the fact I can keep the original milage, in the original speedo (sentimental bugger!)

The lathe i've got is:
http://www.chestermachinetools.com/Products/Product.aspx?productID=11

It's one of those generic lathe/mills that you see around Machine Mart/Clarkes etc. To be honest i'd say it's adequate, build quality is ok if you don't push it to hard, for simple jobs like spacers, or brackets etc it's ok. I actually got it second hand so it wasn't that expensive, but I think if I ever need to get another i'd hold out for something a bit better engineered like a Myford. Saying that it has done everything i've asked so maybe it is more a case of user incompetence

With this lathe you do get a number of cogs so you can cut metric and imperial threads, with different threads per inch/mm

 

[(RIP) Arkwright]

I've got one of those lathes too, good little piece of kit as long as you didn't buy it new! Mine was as new, but in someones way!

 

[Voyager]

It's one of those generic lathe/mills that you see around Machine Mart/Clarkes etc. To be honest i'd say it's adequate, build quality is ok if you don't push it to hard, for simple jobs like spacers, or brackets etc it's ok.

At £849.00 new that's a lot cheaper than the 1950s Denford Viceroy I bought from a local Engineering Works that had gone 'CNC'.

I've put a 1.5HP single-phase motor and decent forward/reverse control gear in it and it can do most things - power feed/cross-feed etc. Threads go from 4TPI to 244 TPI (what would you want that for ). Its quite large, which is handy and it came with a full set of accessories - Collets, fixed & travelling steadys, 3-jaw & 4-jaw chucks, Face plate, dogs, and I've bought a lot of additional tools to go with it.

Its quite worn though and can't really do the fine stuff any more

I keep looking at new lathes around the £6K mark - and dream .

Just too many hobbies/interests I guess

(Sorry for the hi-jack).

Bob.

 

[bernardofeio]

Hello

Can you please send me the dimensions of the plastic collar from the speedo? Mine is missing and I can’t find the dimensions. Since I bought the bike I have the speed cable attached with some plastic zip ties….

I will also try to machine one.

A sketch would be nice…

Thanks

 

[stuart jenkins]

Hi Bob,
I paid £350 for mine, but it was second hand, not sure I would pay £849 for it new though, i've seen Myford 7's with a lot of kit go for that, I'd probably hold out for one of them and get a separate mill.

Hi Bernardofeio,

Here's a sketch of the piece I made. To mark the holes that the mounting screws go through I just put it in the case and marked them with a scriber, and then drilled them out by hand.
You will need the plastic sheath that metal drive spindle goes into, if you haven't got this then i suppose you could incorporate this into the design of the piece you are going to turn, the central hole would then need to be a fraction bigger than the drive spindle, and the length of the piece increased to replicate the length of the plastic sheath (this is the part that the speedo cable butts up against), I hope this helps.
Regards
Stuart

 

[bernardofeio]

thanks!!!



note: I will also have to do the plastic part

 

[bernardofeio]

hello

my speedo if back to life! thanks Stuart! I machined a part similar to yours!

now I have one question. when I'm driving at 50kms/h it only marks 30kms/h

how can I adjust it? I still didn't put the glass in again

 

[stuart jenkins]

Hi Bernardofeio,
That's great, i'm glad it worked

You can pull the speedo needle off (be careful with it), and then turn it on the spindle. The spindle has grooves on it, so if the speedo is under reading move the needle one notch clock-wise, and test against a sat nav, if it still reads under move it another notch clock wise etc.

I found on mine that when the needle is at 'rest', it actually needs to be a little under the needle stop post (0mph) by about 6mm, so I eased the needle onto the spindle just a little, and then turned it so it cleared the 'stop post', before pushing the needle all the way onto the spindle.

I did mark on the dial face with a pencil where the needle fell at rest (under the 'stop post'), just so I had a mark to work from if I needed to adjust the needle, but luckily it was spot on first time.

I suppose the other thing you could check is that the piece you made isn't binding on the drive shaft that the speedo cable goes into? stopping it turn freely? Maybe make sure that's well greased.

I hope this helps, with my speedo woes cleared up, it was my starter motors turn to pack up, but that's been sorted, and i'm now waiting for the third thing to come along!!

Cheers
Stuart

 

[bernardofeio]

hello

what is the purpuse of "small 'y' shaped flat piece "?

and how do you take the neddle of? does it have any stopper?

 

[stuart jenkins]

Hi Bernardofeio.

I can only think that the small 'Y' piece is maybe a counter weight, stopping the needle moving to quickly? I'm not really sure but I had to glue mine back on as it had come off from the back of the needle.

You can pull the needle off the spindle, I gripped it with my fingers on the black plastic centre part, and gave it a firm and progressive pull, it is on there tight but not glued (well mine wasn't!), maybe grip the spindle with a pair of pliers, but be gentle with it. Be very careful of the white needle part, as it's only very thin aluminium and bends/distorts/breaks easily.

Cheers Stuart

This image shows the 'spindle' that the needle pushes onto, you can see the grooves/notches on it.