im building a custom chopper and i want to use a chain and sprockets instead of a belt,im using an ultima frame based on the 1984 to 1999 softail frame.ive got a 200mm rear tyre.so was just wondering what i need besides rear sprocket,chain and front sprocket

Chain gaurd

ive already got that,i was thinking i mite need a spacer for the front sprocket

See how it lines up and go from there if you need spacers

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Assuming your rear wheel is centred & straight.

Mount the rear sprocket & space it as to miss tyre & frame.
This will give you the off-set of your front sprocket.
As mentioned you can buy front sprockets with offsets.

If you can't PERFECTLY match alignment with your front sprocket,
You may (if you have the room) have to re-aligne the rear sprocket

Work along those lines

thanks crowy,when you put it like that it sounds easy