In 1985 Nintendo kept North American children glued to their consoles via the magic of poorly designed motocross bikes. We were so stupid back then.
Trying to apply real-world logic to classic video games is silly. They weren't built for realism back then. They were a form of easy entertainment, and sometimes developers had to put artificial restrictions into play in order to heighten the experience. That's likely why the bikes in Nintendo's classic Excitebike are, as Dorkly points out, broken.
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