It's easy to simply have a 1300cc limit, easiest on the inspecting/verifying, and simple.
But a SIGNIFICANT amount of the reason behind this issue would be to attract more people to go out and race. There are thousands of street legal cb750s out there. And with various amounts of performance mods.
If there was only one class with essentially unlimited displacement, no one with a nicely built 836 is going to be very interested once a 120RWHP monster engined bike shows up. Plus, a 1300cc race motor in a factory wheelbase chassis sounds a little sketchy to me.
If, for example, the tried and true Bonneville oil volume method(good enough for world record verifications) works to measure one cylinder easily through the spark plug hole (no teardown required), this seems to be a reasonably simple way to handle displacement classes. Just like Bonneville, only a safety inspection to go race. Only need to do a brief displacement measurement if you break a record.
So say a:
736-836 class
836-915 class
915- whatever the class wants to cap it as class.
If a displacement check only for a broken record is too burdensome, you could cut it off by carbs. Say a class for factory carbs, and everyone else. But this penalizes some small displacement bikes with aftermarket carbs and gives unfair advantage to bigger engine bikes that run bored out and blended factory carbs.
I like the idea of being able to bring people new to drag racing out with their street bikes. Get a taste for it, and maybe have a shot at setting an ATTAINABLE record amongst your peers on similar equipment. Perhaps it would inspire others to build a dedicated racer at some point. Plus, a new racer would be able to enter BOTH the Eliminator bracket and the Street ET class at the same event for more seat time.
Man Cup already has the Super Street class records. Frankie and Billy are doing battle on lower mid 10 second bikes at 125mph with long swingarms and 180 series sticky tires. Great stuff. Perhaps others will join them, and perhaps this opportunity to create a set of national record index classes could inspire more to participate and have some fun.
I can't imagine any reason to ban aftermarket wheels as long they are used in sizes that people agree on per class.
Overall, I like the idea
George