Speedometer help!

[Snowy]

Any help greatly welcomed!
Running 1961 A10 Golden flash, running really well, and still inducing Cheshire cat smiles when ridden!
BUT, the speedo!
Not even sure if it's the correct one, but running approx at 1/2 actual road speed, i.e. travelling at 40, indicating 20.
Please have a look and confirm if this is the correct one for model / year?
I did think of trying an 85mm digital GPS one, but will need 2-3 mm taken off the upper nacelle hole, so would be expensive if ever reverting to original!
So, considering an Indian sourced (budget!) one from Ebay, what's the deal with these?
Says will fit 1961 BSA A10 Gold Flash, looking through the comments here not so sure,
Is a new speedo cable (different fitting?) required also?
Are diameters fit for direct replacement without mods to nacelle upper?
Are they accurate enough not to attract fan mail from speed cameras?
Any comments / help considered and appreciated!
Thanks,
Dick Snow.

[BigJim]

A Few variables elsewhere to think about. What engine sprocket teeth have you got? Also clutch chainwheel teeth and rear wheel sprocket teeth. The numbers will affect speedo accuracy . Mine is generally a bit down, approx 10% which i allow for near police cars and speed cameras. Doing some checks with a second bike, ie holding 50 and asking what their speedo read etc. Others will know about replacing or getting serviced for sure.
Cheers

[jhg1958]

Has anyone fitted a 85 mm gps speedometer to a golden flash? 

Seems to be a good way to get out of the difficulties with ratios or changes in numbers of teeth on the sprockets.

John

[RDfella]

Travelling at 40 but indicating 20? Must have a Bantam rear sprocket! No amount of gearing change would give an error of more than around 10%, never mind 50%. Must be a wrong speedo unless, of course, it is in dire need of servicing.

[Colsbeeza]

G'Day Snowy,
I also have a 1961 GF. Attached is a photo of my speedo face, and the Smiths Listing for 1958.
It has the Number SC 3305/04 (The 04 for a mph Speedo, 05 for kph), and above this the number 1440 which is the number of input shaft revolutions per mile travelled.
My Listings end in 1958. Someone else may have correct numbers for 1961, but mine is correct for 1958 and probably unchanged through to 1962.?? Anyway it does indicate correctly.
Your Number ending in B is behind the needle so cannot read the whole number, but I could not find any speedo ending in B for any British Motorcycle, at least up to 1958. A bit of a mystery.!
HTH Col

[Black Sheep]

Why not send it off to Speedograph Richfield or Russ at Chronometrics.co.uk and get it calibrated? Much better than piddling around with an Indian repro.

[groily]

That one looks pretty much like the 85mph one I had on my B31 if memory serves, but no idea what the numbers were on that.  Not for an A10 anyway I don't think.
Looks odd to me that the needle is set on its spindle at about -20mph while at rest (unless Specsavers need to see me again). Dunno if that's relevant, but the difference looks about what would give you a reading of 20 at 40mph.

[Rex]

Taking an educated guess while riding is better than an Indian repro.
Aren't they merely for filling a hole in the headlamp?

[Swarfcut]

  I've only ever seen A10 Speedo's with an additional trip display, so I reckon that is not the original. To endorse RD and Mr G, if a bent needle is anything to go by what lies inside is not for the likes of us, it's a definite job for the specialists. Of all the parts on an A10, it must be the winner for the most complex component and  the ultimate complicated way to indicate road speed. More gears, spindles and other mysterious parts than a cheap watch.

 Indian speedos certainly look the part and are a simple magnetic type. Cable entry is central, casing is deeper, so mounting sometimes a problem. Cable connections are also different. Better than nothing, little experience of how well they last, but from current price levels and ultimate source I'd reckon for "display purposes only" let alone being accurate.  Getting any chronometric instrument refurbished is expensive, as is sourcing a non functioning unit as core material.

 Swarfy.

 Additional. Your chronometric may be worth more than you think....

[Snowy]

Has anyone fitted a 85 mm gps speedometer to a golden flash? 
John

That was my preferred choice, but all found are 85mm, taking original out, the hole in nacelle top is 82mm, and o/s diameter of Speedo bezel is 85mm, so would be no way back unless a plastic rinter could be used to fabricate a spacer!

[Snowy]

That one looks pretty much like the 85mph one I had on my B31 if memory serves, but no idea what the numbers were on that.  Not for an A10 anyway I don't think.

Thanks for feedback, and seeing the pics of the genuine one I'm in agreement. No trip reset or numbers that correlate to rpm / mph. Think it'll be left in as a hole filler and an enduro / bike style one will be fitted on as an extra, just won't look right!

[Topdad]

Snowy , I've fitted a cheapo indian one to my A10, Used Vernhill to make me a cable with the correct (enfield end) working on the idea  if it lasted a month it was worth £29  as it is it's been on 3 yrs plus and works well  ,is accurate .I made a fitting but sure you could fit in a nacelle .

[Snowy]

Just phoned those helpful folk at Kidderminster, confirmed that bike should have trip-ometer as well, so deffo incorrect unit fitted!
Replacement about £400, less some for mine if serviceable, it is a genuine Smiths', just the wrong bl**dy one!
So, back to alternatives, 85mm GPS thin and take a file to the nacelle, go Indian as to Topdads comments or get modern push bike GPS thing and bolt to handlebars?
decisions...........

[Colsbeeza]

Snowy,
Just to complete the picture on the Speedo Numbers, the SC3305/04 commenced in 1958, and according to the attachment, went right through to the end of A10 production.
Col

[Snowy]

Snowy,
Just to complete the picture on the Speedo Numbers, the SC3305/04 commenced in 1958, and according to the attachment, went right through to the end of A10 production.
Col

Col, thank you so much for your input, the photo was the best start fo me and all the detail as well confirms that incorrect speedo head fitted.
Not fitting Indian replica if gotta faff with cables, see solution below!