Selling an automobile on ebay payment question?

my question is I am selling a bike on ebay to a guy in Texas (im in VA) he is going to pay me 3500 now and needs to pay in 3 large installments to complete the transaction. The guy sounds legit (gave me his ebay info to log in since he wasnt around a computer to purchase using buy it now). I have all his info including banking and routing number. He wants to secure his side of the deal by me shipping after he pays the second installment. I dont feel comfortable even with all his info doing so but cant think of a way to make him rest ure that hes not wiring thousands of dollars to my account and will not receive a bike. We have the same bank as well. He also suggested that I could mail him the title and then send the bike after the last payment but im skeptical since its legally his with the title. Any input would be helpful and he did use the buy it now on ebay so its not an on the side sale. Thanks, Brad