[Closed] Know about motorcycle engines? Please help me understand something!

OK ..apologies if it sounds daft and unimportant but I have an interest in motorcycle mechanics having always done basic servicing and maintenance work on the various machines owned over  the last 40 yrs but not much involving engine stripdowns . I like to understand things in depth and was thinking the other day about primary drives and a question popped up in my head  that I haven't been able to find an answer to so if anyone can help it would be appreciated.here we go !

I am aware the crankshaft generally drives the clutch outer either by 1/ a gear or 2/ a chain or belt. In the first case the clutch outer will spin in the opposite direction to the crank and in the second case the same direction .What i want to know is that if most gearboxes just have a mainshaft ( connected to the clutch ) and a countershaft (which eventually drives the front sprocket) it would mean that the rear drive chain would rotate in a different direction depending on the  type of primary drive you have . Obviously the final drive chain always wants to be rotating in a direction so that the bike moves forward so how is this achieved with 2 different primary drive types? there is obviously something I don't understand unless the crankshaft turns in a different direction depending on the type of primary drive. Hope you understand and sorry if I haven't explained my question clearly but hopefully someone will understand and put me out of my misery! thanks in advance..Bill.