Just got around to putting new chain/sprockets on my 07 Bandit 1250.
To my surprise the PO had 17 tooth front and 40 tooth rear. Stock is 18/43, which is what I bought. I put 20k+ miles on that bike with some LOW gearing. Never had a clue.
Anxious to experience 18/43 gearing now, especially on the highway.
Just need to get my hands on a chain riveting tool...