So here's the short summary: On an email list I participate it, there was a discussion recently about how to adjust chain slack. What I wrote was that Honda (this is a superhawk list) based their slack recommendations on the bike being unweighted. If you weight the bike, then line up the centers of the swingarm pivot and sprockets to find the point of most chain tension, adjust to be snug (but not tight) there, and you're done. Otherwise follow the book.
Someone else replied and said he adjusted it with them centered, but with the chain just hitting the exhaust header (we have dual pipes so headers on both sides) intentionally. Naturally this would result in the chain sliding all over the header when not centered, so he puts a hose clamp on there to protect the header and replaces the clamp when it wears out. He said this was how he was taught by "a guy who forgot more about chain tension than I ever knew" (this reply was after I questioned that practice).
His justification was that, as he put it, chains on a V-twin need MORE slack than those of an inline-4. He said that the power pulses were harder on a twin. Now, granted the pulses of a twin will not be as smooth as an inline, and they are not on a 50/50 cycle based on the crank rotation. However, it's not like the engine is putting more power out. It's still producing just as much HP, but the pulses come half as much as an inline. Anyway he seemed to think that this meant that the chain should somehow be looser.
I think he's full of it, personally. Anyone care to comment? What do you think? Should the erratic engine pulses of a twin require (for reasons I just can't figure) a looser chain than an inline, all other things being equal?