Ah... offset Sporty, why oh why!!!
Sporty came from the K, K engine is also offset (but was narrower on the left side, smaller clutch pack...)
After thinking about it long and hard, it comes down to one thing...
K/KH/Sporty have the same rear chain line as the WL, about 94mm from wheel centre... Put another gear in the gear box and keep the same chain offset means offsetting the whole engine to the left.
But why would they want to keep the same chain line as the WL? Probably to do with the WR and KR that shared a lot of the same components, rear wheel, hubs, sprockets... That's the only logical answer I could come up with... Not to forget as well that in flat tracking, where you always turn on the left, it makes the bike easier to steer on that side...
Which brings the next conandrum... In the H-D Engineering Dept, which was 1st on the drawings, the K or the KR!!! (there are other clues in the engine, K and Sporty alike, that point to the KR being the 1st...)
If anyone has a better explanation, I'm all ears!!!
Patrick