Personal Loan for a young credit history?

I have no credit cards, but I do have student loans that are subsidized. I am looking to get $2600 for a motorcycle as a means of transportation, but the Honda, Suzuki, Yamaha, say they can't finance me cause my credit is too young (my credit score is 680), even though I have been working and doing my taxes since I was 15 and currently still employed in the University of Houston. Is there any other way of getting financed or a personal loan without a co-signer.