Just over ten years. Congrats on your discovery! Technically the T-100 is not that old. But the very first Hinckley Bonnies (model yr 2001) came with chromed engine cases. No tach though. Then the Bonnevilles yielded their chrome cases to the T-100s. Kinda why I want a 2001 Bonneville.
The fit of the Bonneville is not the same as either the Bonneville America, America, or Speedmaster. Quickly, the position of the foot pegs, bench seat vs saddle, bar position, saddle/bench seat heights. Rake and Trail differences too.
