Simple Question: May I use WD40 to lubricate my single-speed chain? Does it not have any negative effects in terms of the chain performance and biking in general?
AFAIK WD40 would clean, but won't lubricate. And generally isn't really meant for bikes. Also one should be very careful with WD40 around wheel rims and breaks for obvious reasons.
As to the lubrication I've been told in a shop to use a lubricant after every ride (I live in Ireland, YMMV). Wipe the dirt, drop a drop of the lubricant on every link, wipe it again.