Who's Faster?

Sometimes, being a Writer is difficult.
Because I want to be somewhat accurate in what I put down on the page.
But there are times when Google....doesn't have an answer I'm seeking.

Last night I had a question, and google...failed to answer it.

What was the question?
I really wanted to know if a hamster would be faster then a human.

I mean, logically I know the human is faster. We are like 40 times bigger, We can cover way more distance.

But what if they were the same size?
Who would be faster then?
The human still?
Or would the hamster have the advantage?

Four legs, or two. Who would win?
Does the size matter?
I mean, if the human were hamster sized...who would win?
What if the hamster were human sized...would the same one win or no?

All I could figure out is that the fastest a hamster could run would be around 7mph, but not for long.
While a human -normal, not an Olympian- could possibly top off around 15mph.

But would that speed stay the same or change depending on the size?
That's what I need to know.
I mean, if you shrink down a human they wouldn't weigh over 100lbs So would they be able to go faster?
And if you increase a hamster to human size, they would no longer way like 2oz. So would they be slower? ...or would the advantage of running on four legs mean that because the hamster is bigger he'll be able to cover more distance in a shorter period of time and therefore would be faster?

See why I need google? I want this question answered! It's driving me crazy.

-Sarnic Dirchi