I have seen listings for a 13 tooth front sprocket. I am currently running a 14 on my 2006 620 monster. Any one familiar with this set up? Any swingarm clearence issues?
I would expect clearance issues and "enhanced" chain wear.
These guys have absurd rear sprocket sizes http://sprocketspecialists.com/product/ducati-m620-s-ie-rear-motorcycle-sprocket-yrs-02-04-sku-179-large-55-74t/
When I raised the back of mine I got alot of chain rub with a 14 tooth sprocket. I would think 13 would rub bad at any ride height. Larger rear is the way to go
Go up in the rear.
The radius on a 13T front sprocket is too small for a 520 chain. 14T is borderline from what I've read on it, but Ducati used it up to 100HP motorcycles. Please consider swapping the rear sprocket.
I don't even like that my 14t rubs. I had no clue they made a 13t.