Adjustable Cam Gear Swap For Early Fixed 900

[ducpainter]

My monster has no flange on the cam pulley.

The ones on the layshaft will keep the belts from walking off.

[junior varsity]

That's the ones I'm talking about that are flanged.

The pulleys at the heads have the washer behind them, between the spacer/bearings, but that's been all I've seen.

[ducpainter]

Some bikes had the outer edge of the cam pulley with a sheet metal type flange also. You could peel it off really easily.

I think that's what GM was referring to removing.

[greenmonster]

You read me like an open book, dp.

[junior varsity]

oh, i had no idea the cam pulleys sometimes also had the flange - I've got a whole box of 18T cam pulleys - oem fixed, lightweight fixed, oem adj., and lightweight adj (DP and VeeTwo - and have played with a set of STM which I wish I had bought) - hadn't seen the flange on those, only on the layshaft pulleys or "driving rollers" as Ducati refers to them.

i feel all educated and stuff.  and i like it.

[Düb Lüv]

here's the differences in the 18 and 20 tooth cam pulley timing marks.


the 20 tooth layshaft pulleys are still marked the same as the 18's.
the 20 tooth DP layshaft pulleys have a different backspacing than the 18 tooth steel ones.


also the layshaft washers are different thicknesses.

here's the 900 layshaft washer


and here's the 1000ds layshaft washer


to solve that problem i just doubled up on the 1000ds washers. easiest way.

now tackling the layshaft pulley spacing differences.
i measured what i call the backspacing from the flanges size to the inside surface. here's how i measured.


the 900 steel pulley is 7.28mm
DP 1000ds pulley is 9.95mm

to compensate for the roughly 2.67mm thickness difference i used 2 of the 900 cam pulley washers that are a hair over 2.0mm thick.

before and after how i reshaped the 900 cam washer



now to the pulley widths are differences. picture shows how i measured them.


900 steel is 20.40mm
1000ds DP pulley 20.85mm

so with my caveman math, i think i'm in the clear.

here's how the pulley washer configuration goes.

ENGINE-reshaped 900 washer-DP pulley-2 1000ds washers-DP pulley-reshaped 900 washer-castle nut washer-castle nut

i'm sorry, but i tried compiling all this information in a neat fashion.

[Düb Lüv]

here's my not so fancy timing belt inner timing belt covers.





they peek over the timing belt just a little.

[Rudemouthsky]

Hello

I'm looking to upgrade my fixed pulleys to ergal adjustable that I will anodize; however I'm not exactly clear about a couple things:

18t is what my 96 have; what advantage to going to 20t is there? DL, is it because those are the parts that were available to you?

If I stick with 18, am I correct if I believe that what I'll need is this kit:

http://www.speedsupplies.com/accessorylistingdetailpurch.asp?item=23610 (18t version)

What flanges and washers would I need to complete the job? will part 16011051A  referenced in the OP work with both the 18t and 20t pulleys?

Called Ducati Seattle, Ducati Omaha, and Commoto today and none of the parts guys had a clue...

Thanks

[Rudemouthsky]

Seems to me I'll need te 18t kit:

96436503B

Combined with2 flanges:

16010761A

Along with the special washers and torx screws...I just want to be sure I'm not missing anything...

[Speeddog]

The advantage with going to 20t is then you'll get to buy DS1000 belts and struggle to get them on and off the layshaft pulley.

18t will keep life simple.

Dunno about that 'kit' you linked, it's not very clear what all you're getting.

I suspect it's just aluminum pulleys that fit the adjustable OEM hubs on the heads.
So unless you already have a set of those, you'll need to buy those too.

[Düb Lüv]

I just used the 20 tooth setup since a new set of DP ones came up for sale cheap. At the time I couldn't find any fuel injected adjustable pulleys, DP 18 tooth pulleys or the STM ones. I made due with what I had.

[Rudemouthsky]

Anyone know which bikes came from the factory with 18t adjustable cam pulleys, or where to source the "hubs" I would need?

[Speeddog]

You can buy a set of hubs and screw plates brand new for ~$100.

A cursory check of parts catalogues showed that ~'01 and after have adjustable pulleys.

[Rudemouthsky]

You can buy a set of hubs and screw plates brand new for ~$100.

A cursory check of parts catalogues showed that ~'01 and after have adjustable pulleys.

I guess I didn't know what I was looking for...Ducati Omaha is even more clueless than me, they're acting like I'm asking them to decode the Bakshali Manuscript.

[Rudemouthsky]

The "hubs" you're referring to aren't the flanges I've already referenced? I must be blind because I don't see anything else in the diagram besides those and the screw plates/washers.