Any “bike” (bicycle, unicycle, tricycle, motorcycle, motor scooter, carbon fiber superdillyicious alloy tri-bike, et cetera) will need to be properly stored away from the elements if you want it to last more than a single season.
And if you’re caught out in the rain/mud/whatever, your best bet will be to wipe down the “bike” when you get home to stop the corrosive effects of whatever sludge has built up.
Keep it clean. Keep it dry.