Only mod is the noid delete which restricts WOT in third gear (to meet noise regulations). Love the bike and torque from the V twin. But maintenance is high. The valves need to be adjusted every 8k miles. The rear sprocket is aluminum.
Note the front brake is a perimeter brake system. Fuel is in the frame. I bought the bike because I appreciate engineering.
Harley fucked over Erik Buell and his company, and basically ensured it wouldn't ever threaten their main line.
Buell bikes are finally starting as a new company again, but I wouldn't ever credit any of Erik's success to Harley's dumbfuckery