"why don't you want me to come to your home to pick it up?"

1. i don't know you.
2. i'm not selling my home, i'm selling a bike or part.
3. i live on a huge hill and don't want you to try to gear down going up on my beautiful bicycle when you don't know what you're doing giving you the opportunity to fall and sue me ... or worse, injure my beautiful bicycle.
4. there are better places to test ride my bike with less risk.
5. normal people don't mind meeting at the park a couple blocks away.
6. at the point we actually meet, you have either my email, phone number or both, and it's easy to reach me through my ad.