PiBoSo uses an asymmetric cryptographic algorithm. A keygen might produce a string that looks like a key, but when the client asks the server to verify it, the server will reject it immediately. Modern versions of GP Bikes rely on online verification for the core executable.
While a free demo of GP Bikes is available, it is strictly limited: gp bikes license key verified
If you want, I can instead help with any of the following legal, constructive alternatives — pick one: PiBoSo uses an asymmetric cryptographic algorithm