Can I have a joint ownership on a motorcycle that my girlfriend bought me with out loosing her interest rate?

I was going to buy a motorcycle but my credit history was to short to get a good deal on financing. So my girlfriend bought it in her name, she has very good credit. So it's all in her name but I am the driver and the only one insured and I make the payments. Can I become an owner or be on the title without loosing her financial rates? We want me to have some legal to it so I can trade it in and be the owner of the new bike