I'm so glad to read comments advising against using WD40. I wouldn't have the stuff within a mile of my bike.
I always apply duck oil after washing down the bike though. I still make sure to keep it away from any area that has bearings etc.
I don't actually leave it on the bike though, as I use it as part of my cleaning regime, and use an air line to blow it off, and then wipe the bike down with a cloth.
I then apply ACF50 to parts which may corrode, but exclude the chain from this. I tried it once as a test, but it just goes horribly black and gungy, and is a pain to remove.
In respect of the chain, after cleaning it, I apply either wet lube or dry lube depending upon conditions. I frequently find that I have to re lube a chain before, during and after a ride. Hardly surprising though, and the longest that a factory new chain has managed before having to be oiled, is two rides in winter off road conditions.
I've yet to find any product that lasts more than 20 miles or so in these kind of conditions, and I've tried countless different products. None are able to cope.
The soil condition here are so acidic, that even after just a couple of hours of rest, corrosion starts.
All credit to KTM bikes for the superb build quality, chain wear aside, the bike just shrugs it all off
Anyone for grinding paste!