175 TS Speedo Drive Replacement

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Samurai
Posts: 137
Joined: Wed Nov 28, 2012 9:53 pm
Location: Somerset, U.K.

175 TS Speedo Drive Replacement

Postby Samurai » Wed Apr 24, 2019 8:22 pm

Ok, here's my latest problem!

During a great 50 mile round trip in the sunshine on Saturday, with the bike running beautifully, the speedo started to under-read drastically and in the end, hardly at all.

Long story short, having taken the Veglia speedo drive apart, it's apparent that the large brass helical gear, that engages with the small, cylindrical worm-drive, has become very worn, which is also evidenced by brass 'dust' inside the drive. I've cleaned everything up and re-greased and assembled it, but you can feel and see (I put the end of the broken cable into the drive), that the gears slip about halfway round. This would explain why it was only registering about half the speed and distance on that ride!

I've looked on EvilBay and there are a number of secondhand and a couple of new drives for sale, but I'm unsure what the drive ratio of mine is and which may be compatible? Is it simply a matter of counting the number of teeth on each drive gear and is the width of the whole drive common to all with the same diameter axle hole?

There is a new 'reproduction' one below which is made in India, but I'm aware that these things can be of 'variable' quality. is the 20/10 ratio correct for the 18 inch rims on the bike and does anyone have any experience of these Indian-made reproductions?

https://www.ebay.co.uk/itm/NEW-AFTERMAR ... SwZqZaGv2Z

As an alternative, does anyone have another suggestion as to another source or compatible version? Similar drives appear to have been used on a number of different bikes in the 50s and 60s, but most seem to be either very slightly different to look at and possibly in width and fitment. The only thing that bothers me with a secondhand one, is that it may well be in the same state as the one I've got to replace.
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Last edited by Samurai on Thu Apr 25, 2019 7:08 pm, edited 1 time in total.

ducwiz
Posts: 604
Joined: Tue May 22, 2012 12:52 pm
Location: near Frankfurt, Germany

Re: 175 TS Speedo Drive Replacement

Postby ducwiz » Thu Apr 25, 2019 7:49 am

175VS.FC1008 is the related part number according to the spares cat, and is possibly mentioned in the ebay offers. Unfortunately, the catalog gives no direct info about the gear ratio, but mentions "attack 1 MC". Can somebody imagine the meaning of this phrase?

Hans

Samurai
Posts: 137
Joined: Wed Nov 28, 2012 9:53 pm
Location: Somerset, U.K.

Re: 175 TS Speedo Drive Replacement

Postby Samurai » Thu Apr 25, 2019 11:24 am

Thanks for that info Hans, that may help to pin down a suitable replacement.

ranton_rambler
Posts: 439
Joined: Sun Jun 04, 2017 11:33 am
Location: Stafford UK

Re: 175 TS Speedo Drive Replacement

Postby ranton_rambler » Thu Apr 25, 2019 5:57 pm

Does the end cap have anything stamped on it - mine says "18." I can vaguely remember counting the in/out turns and I think it was 18-10 but can't find anything in my notes. If I get chance I might do it again.
On mine the little drive tang was broken off, but I was able to carefully knock back the staking to remove it. After measuring up, I got one of the CAD jockeys at work to make me a DXF so I could get a new one lasered out. It works but I've no idea if it's accurate yet. Will do a GPS speed check one day.
If you just want to know the speed, some of the vintage guys use a bicycle speedometer.

Samurai
Posts: 137
Joined: Wed Nov 28, 2012 9:53 pm
Location: Somerset, U.K.

Re: 175 TS Speedo Drive Replacement

Postby Samurai » Thu Apr 25, 2019 7:17 pm

Ian, I've just uploaded another photo of the front of the drive and have just noticed a couple of figures. One looks like '66' and the other, which appears a little distant from the other and so maybe unrelated to it, is a '3'. Other than that, it doesn't appear to have any part number or ratios on it.

I counted the number of teeth on each gear and I believe the worm gear has 8 teeth and the ring gear has 15, but I've no idea how this relates to any of the 'ratios' that I've seen on adverts so far e.g. 20/10 etc? The total width is 15mm at the widest point and the inside diameter for the axle is 15mm also.

The bicycle speedo is a good suggestion to get me on the road again, but I would really like to get the bike's one working before long. So, if anyone knows of a good, suitable spare kicking around, I'd be most interested.

ducwiz
Posts: 604
Joined: Tue May 22, 2012 12:52 pm
Location: near Frankfurt, Germany

Re: 175 TS Speedo Drive Replacement

Postby ducwiz » Thu Apr 25, 2019 8:35 pm

r_r:
Does the end cap have anything stamped on it - mine says "18."

Possibly, this number indicates the rim dia. 18" for 125, 175, 200cc, 17" for 160cc ?

Hans

Samurai
Posts: 137
Joined: Wed Nov 28, 2012 9:53 pm
Location: Somerset, U.K.

Re: 175 TS Speedo Drive Replacement

Postby Samurai » Fri May 03, 2019 5:30 pm

I've searched high and low for a direct replacement Veglia drive on the internet, but so far no luck.

I trawled the Bay of Evil, and turned up a NOS CEV speedo drive in the USA that appears to have the correct ratio, but having received it I've got a couple of issues with it fitting, nothing is straight forward :roll: :

1. I need to find a 'reducer' for the original M12x1.0 speedo cable nut to get it to attach to the CEV drive's smaller M10x1.0 male stub.

2. The drive 'tang' that inserts into the front hub is much too short and will need to have an 'extension' welded on to fit.

Hopefully, I can get these sorted and it all works Ok.

However, as a fall-back, I think I've got a couple of other options as I see it:

1. I've noticed mention in some threads of people fitting Smith's speedos in place of the original Ducati/Veglia one and was wondering if anyone can point me towards the correct version and relevant speedo drive for the 18'' wheels on the 175TS?

2. Can anyone suggest a source for obtaining the correct Veglia drive (new or second-hand)? I've tried the obvious places like Classic Ducati and Nigel Lacey in the UK, as well as a couple of Speedo repair specialists, but so far no luck. I can't believe that there isn't somewhere in Italy or Spain that stocks one, although I've so far been unable to find any . . .

Any help will be much appreciated, as this 'simple' problem is keeping the bike off the road and I'd rather try and sort it properly than try and bodge a bicycle speedo on.

ranton_rambler
Posts: 439
Joined: Sun Jun 04, 2017 11:33 am
Location: Stafford UK

Re: 175 TS Speedo Drive Replacement

Postby ranton_rambler » Sun May 05, 2019 5:26 pm

I had some profiles made as my drive tang was broken off - as photo. I have some spares (in flat version). If you're interested, let me know your dimensions and I can check if same. If not, I would suggest braze or solder yours, rather than weld.
I think Venhill make speedo cables, so could make you up a new one with correct ends.
DSCF5669small.jpg
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Samurai
Posts: 137
Joined: Wed Nov 28, 2012 9:53 pm
Location: Somerset, U.K.

Re: 175 TS Speedo Drive Replacement

Postby Samurai » Wed May 08, 2019 6:09 am

Ian, many thanks for the offer, I may well take you up on it yet. However, yesterday I had time to play around and by careful bending and the fortuitous discovery that if I inserted a small well-nut into the Speedo drive hole in the hub and inserted a small, round-headed bolt into it, I could get it to 'catch' the tang of the drive gearbox make it function.

I also managed to find a reducer to enable the m12x1 cable end nut to fit the m10x1 male connector on the CEV speedo drive. That will hopefully turn up today and I can then see if it all works. I'm sure that 'the bike which just keeps giving' will have other ideas though :roll:

Samurai
Posts: 137
Joined: Wed Nov 28, 2012 9:53 pm
Location: Somerset, U.K.

Re: 175 TS Speedo Drive Replacement

Postby Samurai » Mon May 13, 2019 5:50 pm

This is turning into a bit of a nightmare!

Finally got hold of the CEV Speedo drive from the States and everything looked Ok, except the brass output connector for the Speedo cable was at the top of the drive when mounted, as opposed to the bottom as on the original Veglia part. However, the drive ratio appears to be correct.

I ordered a new original complete Speedo cable, as the old outer sheath had been ripped at the end when the old drive finally locked up. I also ordered a separate DIY inner cable, so that I could cut it to length, allowing for the m12x1 to m10x1 adapter that I had to buy.

After much fiddling around, I now find that the reason the Speedo refuses to turn when driven by the CEV unit, is that the output direction is the opposite required :roll:

I've searched high and low for the correct replacement drive, but these seem to be as common as unicorn tears!

I'm now left with a NOS Ducati Speedo head, a knackered but compatible Veglia Speedo drive (that nobody seems able to repair the ring gear on) and a NOS and working CEV drive of the correct ratio, but which turns the cable in the wrong direction :cry:

I've ordered a wired and programmable, Sigma Sports bicycle computer just to get me on the road again, but can anyone point me towards a suitable solution to my dilemma?

Failing all else, I need to find a complete Speedo drive and head combination, irrespective of make/age, that will fit the 15mm axle of the 175TS. I hear that the later widecases sometimes use Smith's clocks and drives, but there appear to be several different types and none seem to fit the 60mm hole in the narrow case headlamp.

Any suggestions would be much appreciated.

Thanks guys ;)


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