tach drive housing types

[450jupiter]

Hi, I have seen three different tach drive housing covers. A cover that is totally smooth, a cover with Ducati in raised letters and a cover with Ducati in engraved letters. Does anyone know when these were specifically used? My application is a '69 450 Ducati scrambler and I have an engraved cover which I hope is correct for this model because it was not originally on the bike. Thanks, Erik

[JimF]

I too am anxious to hear what was stock on the bike, but regardless most people would not know what was stock so unless it makes a difference to you no one will likely fault you for it.

Keep in mind that tack drives are a little hard to come by, so I am glad you have one even if it's not 'correct' for your model.

Jim

[Jordan]

A good source of info is from photographs in magazines, in the period the bike was new.

[450jupiter]

I have the one that is all smooth on there right now but found one with the engraved DUCATI which I think is correct for a '69. Thanks for the advice about magazines. This 69 or 70 magazine review I posted on a 2015 scrambler forum last year http://www.beamimaging.com/The_Big_Duke2.pdf (2.4MB link) shows the '69 450 Jupiter with DUCATI on the cover but a little hard to tell if engraved or raised letters. Notice the decal on the air cleaner. Never have seen one of those before. Wonder what it said.

[Ventodue]

Hi Erik,

This is most likely the type that your bike would have had from new. This is for a CEV rev counter. Note that the cable exits at the top and the 'Ducati' is engraved.

Tach drive 1.jpg

However, by 1970 (if not before) there was also this type. Still CEV, cable exit still at the top, but with the 'Ducati' now raised:

Tach drive 1a.jpg

Now for another type ... . This dates from 1970/71, possibly before. The cable now exits below. The 'Ducati' is raised. And note the screw underneath. This was for an optional oil drain. (I have a photo of one of Bruno Spaggiari's race engines with just such an oil line fitted to this type of drive).

Tach drive 2.jpg

And here's a further variation. The 'Ducati' is now engraved and the oil drain screw has disappeared.

Tach drive 2a.jpg

And finally in late 1972 we get this type. Smiths rev counter, no 'Ducati', no oil drain screw (and no leaks, either ... ):

Tach drive 3.jpg

It's all mighty confusing ...

Ciao

Craig

[Eldert]

and there is the smooth cover like the one on the right



try to stay away from the alu CEV angle drive . they have a habit of blowing the endcap out
one of the shafts will fall out and the coupling will damage the bevelshaft .

Eldert

[450jupiter]

Thanks a lot for the input. My bike is a '69 and from the very early advertisements including the magazine article from the Feb '70 CycleSport magazine (link in discussion above), my bike should have something like the tach drive cover and drive Eldert posted above left. Cable exits low. See attachment from a '69 brochure. Also in '69, the new 450 Desmo is shown with a smooth cover. I wonder if that is what they used for the Desmo. Maybe someone with a 450 Mark IIID Desmo can check their bike for the cover. Thanks again for all the great inputs. Erik

[Eldert]

Hi Erik

the bottom picture is a sandcast racing cilinderhead . not a production 450 item
the tach drive cover is sandcast to .

Eldert

[Ventodue]

and there is the smooth cover like the one on the right

Thanks Eldert - hadn't seen that type before ...

try to stay away from the alu CEV angle drive. They have a habit of blowing the endcap out, one of the shafts will fall out and the coupling will damage the bevelshaft.

Do you know, is that why someone has pasted that red or orange 'I-don't-know-what' on the two drives that I posted photos of?

Ciao

Craig

[Ventodue]

My bike is a '69 and from the very early advertisements including the magazine article from the Feb '70 CycleSport magazine (link in discussion above), my bike should have something like the tach drive cover and drive Eldert posted above left. Cable exits low.

Good pick up, Erik! I'm going to change my earlier advice - I think you're right. In Massimo Clarke's Scrambler, Desmo e Mark 3, he reproduces a publicity shot of the 1969 US market 450 SCR and that too has the cable exiting LOW.

Ciao

Craig