changing rear caliper

[Finnpaso]

Brutus changed to much better opinion now! I think, its much better to change chain line offset ab. 4 mm's outside, than change wheel lines... If wheel lines changes, its just very bad handling bike then and it goes(as guys mention. "like a dog") and that is very bad choise....

Anyway, think guys, is it wise to make such mod. to normal 16" Paso stuff, or convert it direct to 17" rims ???? As someone told, that tire selection is much wider with 17".... and much better tires then...

I think, that if want to keep 16" Paso still with 16" tires, then must use Avon Tires(what is best choise just now) and and make about 4mm offset(move to outside surely!) to chain line....

This discussion start to ge very intresting soon..... i am waiting, that someone "hit me" very hardly very soon....

[ducinthebay]

The chainline for the 495 sprocket will be more outboard than the 736 sprocket. The reference for the sprocket is the side that the retainer plate attaches, and that is on the left side.

The 906 (736)has no recess, as the cases were wider to accommodate the newer 6 speed transmission. This will move the chain inboard compared to the 750 sprocket (495). The sprocket width is not relevant in your case. They may have added more material to accommodate more horsepower, and the fact that they had room on the shaft.

Another option is to find an early (rare) 750 Sport sprocket. they had even more offset, or dish for the retainer plate, to move the chainline outboard. I've seen pictures of them, and they are 4-8mm offset I would guess. Some have made a similar modification by simply welding on a large thick washer on the outside of your sprocket and using the center bolt to hold the sprocket on. Antti, do you still have some of those?

As for the case of the Santa Monica, I have to ask what you are measuring?

[Finnpaso]

Yes, i have them still, but as You very well know(and i as i told to You via PM), no anykind of problem to sell them, OR use them by myself, as it can be usefull sprocket for Paso 16" wheels with 16" tires. I dont know yet, what i shall i do with my 750 Paso with 16" original wheels.....

Anyway i dont "destroy" them yet, as i want to see, where things are going. Best solution to me is, that we get some good combination/result with Paso 16" wheels with some good tire combination without those rare 750 Sport front sprockes and i can sell them to some 750 Sport owners, who REALLY need them... .. if i dont need them.

If someone really need fotos of those sprockets, let me know to: finnpaso@gmail.com and ill take some fotos of 750 sport(early modell) front sprockets.

[Brutus]

..As for the case of the Santa Monica, I have to ask what you are measuring?

I called a specialist nearby. They have been for more then 30 years and involved in racing for quite some time. They sold Santa Monica's out of the crates and told me it has 11mm offset rearwheel.

[Brutus]

The chainline for the 495 sprocket will be more outboard than the 736 sprocket. The reference for the sprocket is the side that the retainer plate attaches, and that is on the left side.

The 906 (736)has no recess, as the cases were wider to accommodate the newer 6 speed transmission. This will move the chain inboard compared to the 750 sprocket (495). The sprocket width is not relevant in your case. They may have added more material to accommodate more horsepower, and the fact that they had room on the shaft.

Another option is to find an early (rare) 750 Sport sprocket. they had even more offset, or dish for the retainer plate, to move the chainline outboard. I've seen pictures of them, and they are 4-8mm offset I would guess. Some have made a similar modification by simply welding on a large thick washer on the outside of your sprocket and using the center bolt to hold the sprocket on. Antti, do you still have some of those?

As for the case of the Santa Monica, I have to ask what you are measuring?

This supports my theory. The sprocket is thicker and needs te be machined approx 5mm to make it more offset. It should hold..

[ducinthebay]

Machining the sprocket is an easy fix to get the chainline outboard more. The spline pattern is the same for all Ducatis with the retainer plates. You might find one that has even more meat on it. Sprockets are usually cast, then the teeth are hardened, so machining the center should be relatively easy, if you can find a good way to grip it in a lathe. Maybe if you put a length of chain around the outside it would be easier to center in the chuck of a lathe. The other option is a mill, but from the sounds of things, you know what you are doing there.

But from all this discussion what we know is that on basically the same motor, Ducati had run the chainline much further out on the shaft without bad affect. So moving your chainline outboard, should not be of much concern.

And Antti, thanks for the offer of those sprockets years ago. I got a laser chainline tool, and measured everything carefully, and I ended up with a straight chainline using a stock front sprocket with my 17" wheels and 170 rear tire.

I have a spare laser chain alignment tool if someone is interested. I had already bought one, and some one gave me one as a gift. I sure don't need two of a tool I use once a year maybe. But it sure works well. Found out the marks on the swingarm were way off. http://www.profiproducts.com/profilasercat.html


Cheers,

[Brutus]

Picked up two sprockets today. One is 31mm in width and the offset is 14mm (measured from front sprocket). A quick view shows the sprocket fits on the axle. Only thing is that 14mm is slightly to much.. An extra ring is needed. The other sprocket is standard 906. With some alterations this also could fit.

[ducinthebay]

Wow! Seems as though you found one of those rare early 750 Sport sprockets, or were they also used for the F1 or Pantah motors?. Rare as hen's teeth, as I have only seen pictures of them. Where the heck did you find that? Look familiar Antti?

Even on stock bikes, the chain alignment can be suspect, and the adjuster marks are not always right. (especially early Paso)
Get your rear sprocket on the wheel the way you want it, mount up your wheel.
Measure from the swingarm axle to the rear wheel axle as accurately as you can so you know that the rear wheel is now square to the swingarm pivot. There is a cool tool to do this, and if you are handy, you can make one yourself.
Here is a write up on such a tool. http://www.1000rr.net/forums/showthread.php?t=56362

Now that your wheel is square in the swingarm, get out a laser to see where that new rear sprocket is pointing. This will tell you which of those sprockets you can use, and how much you need to cut/trim/shim/ adjust to fit.

This is the best way to find the perfect chainline, and a well aligned bike.

Cheers,

[Finnpaso]

Look familiar Antti?

"little familiar", as mine, but not similar, as mine dont have so much that "offfset" and i am sure of it. I am talking about fotos nr 3. and 4. (from up to down)

To my sprocket is stamped: 489 15 ....Maybe same manufacturer?

[Brutus]

..Even on stock bikes, the chain alignment can be suspect, and the adjuster marks are not always right. (especially early Paso)
Get your rear sprocket on the wheel the way you want it, mount up your wheel.
Measure from the swingarm axle to the rear wheel axle as accurately as you can so you know that the rear wheel is now square to the swingarm pivot. There is a cool tool to do this, and if you are handy, you can make one yourself.
Here is a write up on such a tool. http://www.1000rr.net/forums/showthread.php?t=56362..

Till now I assumend the rearwheel is allways lined up correctly due to its excenters..

[ducbertus]

believe is for in Church, measuring is exact science.
the method appointed by Ducinthebay I use already and yes, forget the notches as on the 907's.
the excenters as on the 750 and 906 supposed to be better. But the best way is to set it up once right.

ducbertus