I think that the newly announced Basic Twins class for 'Pro' riders is, basically, a good idea.
Under the current class structure, Grand National Experts race twins on half-miles and miles, and race 450cc stock-framed, motocross-based machines on short tracks and TTs. In the only support class, up-and-coming Pros race on the MX-based bikes on all tracks. When this format was introduced a few years ago, many people decried the loss of the 'framers' on short tracks. There were also complaints that the 450s would be far too slow for the Mile races.
'Too slow' is arguable, but the singles races on Mile tracks turned out to be thrilling drafting battles in which -- even by flat track standards -- the racing was a little too close for comfort. It would be a little different, maybe, if the tracks themselves were old-school, deep cushion deals... but they're not; nowadays, they mostly groove up into one-line affairs.
Jesse Phibbs, 21, died a month after crashing in the 2010 Indy Mile. And while I think he was the single class fatality, there have been a few too many close calls. I think twins will prove safer on the Mile tracks -- spreading riders out a little and allowing for slightly different corner lines, even if they're marginally faster. After all, the idea is to bring up promising young riders, not maim or kill them off.
It remains to be seen how the rules will shake out in detail. I presume the new twins will replace singles at all Mile tracks, but what about half-miles? Will some of those be designated 'Twins' tracks and others 'Singles'?
I know it won't make me popular, but I think some consideration should be given to making the Basic Twins class a 'stock frame' class. Go ahead, roll your eyes, but hear me out: When the 450 MX-based bikes came in, people bitterly complained that they were, basically, pieces of shit compared to real 'framers'. But the fact is that while they are slower, cruder bikes, the racing hasn't suffered. More grassroots sponsors -- dealers who sell 450 motocross bikes -- were brought into the sport. And the cost of fielding a competitive machine fell at least a little. Remember the old 883 Sportster class? Those stock-frame bikes were pigs, but the racing was great.
I think the same thing could happen with a Basic Twins class that specified stock frames. Bikes would cost less to build; they'd look more like street bikes and be more attractive to dealer sponsors; they'd look visibly different than the Experts' bikes, which would reduce the prestige erosion at the very top.
I'm just sayin'...