AMA Racing Works to Reduce Noise Pollution at MX Events.

[pplassm]

The redline is pre-defined, as all bikes entered must be approved by the AMA.



We're talking about two completely different things here. AMA MX/SX has nothing to do with road-going streetbikes. If you're talking about the Aprilia 450 V-Twins, they're currently not allowed into Japanese controlled AMA competition.