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Speedo/Tacho T140

16K views 10 replies 5 participants last post by  Mecchanica 
#1 ·
Hi there,

I`m just about to finish a 1973 Tiger TR7V basket-case.
She`s fired up last Saturday already :yayyy:

I`m searching for a tacho and speedo.
The engine-tacho gearbox is missing and the speedo is broken and the speedo-drive is missing as well.

1.Option
Getting Smiths

2.Option
Getting Veglia

3.Option
Something else

I don´t know the ratio of the tacho-gearbox nor of the speedo.
I looked thru EBay for gauges and some got a closer pic of the tacho-face (e.g. RSM 3003/03A) or speedo (SSM 5001/06)
I`ve got no idea what it means.

Is the ratio of Veglia and Smiths (tacho/speedo)identical ?
Should be I guess...

No ideas
Thanks in advance
ray
 
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#2 ·
Just returned home and the backordered "Replacement Parts Catalogue 1973" finally arrived...

It says:
Tachometer: RSM3003/13
Speedometer: SSM5007/00

At EBays there`s an offer:
Smiths Tachometer: R S M -3003/19 R P M x 100 4: 1
Anybody knows the difference between /13 and /19 ??
Or, is there any difference ??

Thanks
ray
 
#3 ·
#1 suggestion
if you don't know what something fits don't buy it 8 out of 10 times you lose

#2 suggestion
a) if you have correct gauges send them to Nisongers and have them rebuilt
b) or go to a swap meet find a couple of correct gauge cores
(pay about $20each) and send them off for a rebuild.

don't like those ideas ...

Option 1 Smiths gauges
covered above
also Speedo and Tach from 68 to 79 are interchangeable the difference is face plate, needle colors. and possible location of mounting studs all the previous cause part number changes

Option 2 Vegilia
to the best of my knowledge the speedo and tach heads can be used as a direct replacement for Smiths. you will have to use a smiths type speedo drive as Veglia fits on the opposite side of the wheel. I have seen it done a couple of times (personal opinion stick with smiths as they were original equipment on your bike Veglias weren't used til late 78)

Option 3 Something else
LFHarris offers a jap replacement gauge set. they will fit and function fine on your bike. will probably cost less than having Smiths rebuilt but not look as good (again my opinion)

your choice your money
 
#5 ·
Hi there,
Thanks for your input!

Today I called up one old feller who used to be in the business of repairing tachos and speedos.
He claimes that ALL speedos and ALL tachos are the same of following late-models:
T120, TR6 Trophy,TR6 Tiger, T150.
He himselves was wondering about cause earlier models did have a different speedo/tacho. Further his younger brother and his gang used to ride (e.g. a 1972 Bonneville) and once he crashed and needed new gauges.

If that´s correct than the speedos and tachos gearbox should have the same ratio (15/12 and 4:1)

I have no reason not believing him but still could someone confirm this ?
It´s an awful lot of money, guess you understand.

Thanks
Ray
 
#6 ·
GulfCoast
I believe the units you refer to are made for and imported by LF Harris. I cant figure why they have two listings as only one tach and one speedo are offered by LF.

happy
68 to 78 TR6/TR7/T120/T140/T150/T160 Smiths Speedos interchange
66 to 78 TR6/TR7/T100/T120/T140/T150/T160 Smiths Tach's
Interchange

different gauges were used on earlier bikes due to different
drives and pick up locations. also early model(63) gauges were chronometric not magnetic as 64 up were.
 
#9 ·
The later speedos (78 or 79 on) have the odometer knob poking out of the bottom. This can work with the 73 if you open up a hole in the bottom of the rubber cup.
63-65 the tachos were 2:1 ratio and left hand swing. These won't work for you. They didn't have a right angle gearbox drive, came straight out of the case.
The cast aluminum right angle gearbox was introduced in 66 and used RH BSF threads until they changed in 69 to a LH UNF thread. So, you will need one of the 69-on gearboxes. The 69-72 cast aluminum gearboxes are much better (and better looking) than the later mazak gearboxes.
Tachos from 66 on, 500, or Trident, 4:1 ratio will work. Beware BSA items, they are 3:1. However, BSA speedos will interchange.
500s to 74 and 650s in 66 used 120 mph speedos with a 2:1 ratio, right hand swing...rear wheel gearbox drive was introduced in 66 and used to the end, a 120 mph speedo in 66, then a 150 mph speedo and 12 : 15 (1.25 : 1) ratio gearbox. T160s used a unique speedo drive, it was mounted on the left side and is a mirror image of most Smiths drive gearboxes. You probably won't run into one of these.
Greyfaced instruments were used from 64 until early 1970. Then a blackfaced instrument with white block numbers through 74. Then a variety of faces, including NVT and one from 78 when they were put out by the workers cooperative.
The aftermarket instruments look more like the Veglia units than Smiths units. Reasonably priced and they seem to work ok.
 
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