Bicycle Mechanics - Bike leaning to the right?

I just purchased a used bike and it rode fine and felt good so I bought it. Today on my ride to work again everything felt right until I rode with no hands and the bike really pulled hard to the right and I almost fell off! Does anybody know of anything I should look for?

were you riding on the right side of the road? Roads have crowns so the water goes torwards the gutters. Try it again in a large flat parking lot see if you get a different outcome.

I tried in three different spots along a bike path(that I have rode other bikes no handed with no problems many times) and it was really pulling hard more so than I would think road grading would cause. I will however try some different areas.

Maybe the headset is too tight, dirty, dry, worn?

Sometimes your cables can pull the bars one direction or the other.

my guess would be the head set. They some times get brindeled

Your bike may be a conservative.

Your bike may be a conservative.

Are the wheels bolted on straight?

Thanks for the advice, I will check my cables and headset. It is a blue bike so I doubt it is a conservative but I will keep my eye on it so that it does not stay the course.

Bent fork.

It's not one of those old Ronnie Reagan Comp bikes, is it?

could be a lot of different things. in no particular order...

1. wheel not fully in fork
2. unequal fork lengths
3. forks offset to one side or twisted
4. frame not aligned (headtube and seattube not in the same plane)

Right pocket full of change?

Bent fork.
Definitely.

http://www.sheldonbrown.com/brandt/align-fork.html

The most likely cause is mistracking of the wheels, from any one of the following causes: off-center or otherwise misaligned fork or rear triangle, wheels not set correctly in frame, improperly dished wheels. Although some of the ideas above are possibilities they are much less likely. Have a shop familiar with frame work check it out or: Put in a stand that allows you to rotate the bike upside down and try to line up the front wheel with the rear. They should be right in line with each other, so that you can sight down the right or left side or over the top (bottom).

Thanks for the advice, I will check my cables and headset. It is a blue bike so I doubt it is a conservative but I will keep my eye on it so that it does not stay the course.

Strange that in the US red is for conservative, whereas in most other countries it's the socialist/communist color. Sorry...... I drifted.:)

Not strange at all, just truth in advertizing. ;)