A little bit of water is not going to rust the bike quickly. The only time you will need to worry about rust is if you have any chipped paint on a steel part ( i.e. frame, tank, chain, triple tree clamps, fairing braces, rear sprocket, front and rear disc) if you have real bad pitting or scaring on a aluminum part they could corrode. It is recommended you lube the chain ( use a good lube that is waterproof and will not fling off) after a ride in heavy rain or long periods of exposure to rain. Pivot points such as gear levers, clutch, brakes, should not need as much lube after a simple rain shower if you keep it properly inspected and cleaned and lube. Cables should be done to OEM specs ( see owners manual) unless you start feel them becoming tight or in the case of the speedo, you might hear it squeal. Your attaching bolts and hardware are either zinc or nickel coated. They will not rust right away unless that coating is somehow scratched. ( such as using the wrong size or improper tool) The Ninja overall is a very well made bike. Unlike cheap Chinese scooters that rust as soon as you wash it. If you keep it dry and out of the elements you wont have to worry about it being a rust bucket in a couple of months. Exposure is you biggest enemy ( and of course the asphalt if you happen to drop it)
