Bank loans are far more expensive at present than dealer finance deals. I bought mine borrowing 3,300 over 4 years (proper purchase deal, not on of this CNC (or whatever) things where you have to buy the bike at the end anyway, pointless). So, 3,300, over 4 years £256 total interest. My bank wanted £20 a MONTH interest, and the bloke thought that was quite competitive! Piss taking jokers.
So, in conclusion, stay away from banks, you can buy a new bike cheaper on dealer subsidised finance than you can a 12 month old used one with money from a bank.
£800 off at the moment too, when I bought mine it was only £500.