So you have submitted the proposed change? The part about not being constructed to jam the chain .... On many bikes a broken chain can and will jam up around the transmission sprocket because it's "pocketed" by the tranny/engine case. This can happen when chain links seize. But many times a broken chain just falls onto the roadway...
Truckedup,
Joe, Tim, Frank, and Jesse
are LTA, so the rule change probably has been made!
What you say about the chain wrapping around the drive sprocket/mainshaft is true, but doesn't usually lock up the rear wheel which is the real issue. I have been at a race where the broken chain locked up the rear wheel with the result being a broken leg (road racing). Incidentally, if the primary chain breaks, it can lock up the mainshaft which can lock up the rear wheel if the drive chain is still intact, the result being a broken ankle as the rider tumbles down the front straight. This I know first hand.
As a part time inspector at Loring, I can live with this new ruling, but I will be looking for some kind of shielding to protect the rider from a thrown chain as I believe this rule is intended.
Tom