Post-Sale Update: This Harley-Davidson X-90 sold for the BIN price of $2,950. One of the oddballs to come from Harley’s time when they were merged with Aermacchi, the X-90 was a minibike produced for just 3 years. This example is in ‘sparkling red’, and it comes with a fold-down handlebar to make it easier to transport the bike. The ’75 …