Can someone kindly confirm the inside diameter size of the rear sprocket?
It's a 1989 model 906.

Also, the owner's manual says it has 41 teeth, but the parts book says 40.
Is there a well accepted preference?

Thanks,
Jorian

90mm according to JT sprockets :

These bikes are fairly tall geared and mine , at 100kph in 6th gear is stumbling along at to low revs,sometimes I used 5th gear. So maybe try the 41

The one here has ID = 92mm, but it is evidently changed to suit an adaptor for use with a wide tyre which is no longer to be used.
The sprocket carrier is also modified unfortunately, down to 88mm.
Does anyone have a spare carrier they want to sell?
Otherwise I'll have to restore this one, which I'd rather not.

Good also to have info on the ratios, so Thanks Folks.

You could get a ring turned up , to fit between sprocket and carrier .....if you did it right you could use a larger/modified washers under the sprocket nuts to hold it in place

I found what I hope is the correct sprocket carrier, and bought it via ebay.
It was not described as being fit for a Paso, but looks identical to the one here (modified).

The received sprocket carrier is an assembly - light metal casting plus steel sleeve, spacers, bearings etc.
The casting looks to be identical, and it's the internal parts that differ. Need to swap them for the Paso bits.
I looked at some drawings of the bevel 900SS assembly, looks like I need to do some press work.
Anyone done this, have any tips or warnings?