Re: I was wondering if Coriolis Force affects vehicles like a motorcycle?

First, let me correct a common misconception in your question. Water in toilets does NOT spin in different directions in the northern and southern hemispheres, despite what you may see on TV shows such as "The Simpsons."

However, hurricanes and large tropical storms do spin in different directions in the different hemispheres. As you say, the reason is Coriolis force. Let's take a closer look at the movement of air in these storm systems before we move on to motorcycles.

The center of a big storm is marked by a region of low air pressure. This low pressure causes surrounding masses of air at higher pressure to move towards it. Now, for very large storms, the high-pressure air must move quite a large distance -- many tens or hundreds of kilometers -- on its way to the low pressure region. That large distance is one of the two keys to understanding the pattern of a hurricane. The other is the fact that the Earth is spinning so that all points make a complete rotation around the Earth's axis in 24 hours. Objects near the equator have to move around a very large circle, while those close to the poles need only complete a small circle. So material near the equators moves at a higher speed than material near the poles.

Okay, now consider a big storm at, say, latitude +10 degrees. The distance it must travel around the Earth's axis every day is (2*pi*R*cos(10 degrees)) = 39,465 km; thus, the air at the storm's center is flying east at 1,644 km/hour around the Earth's axis. Of course, the continents, the islands, and everything else fastened to the Earth is also flying east at the same high speed. If you were standing on an island, it would all look stationary to you.

On the other hand, if a big blob of air to the north, at latitude +12 degrees, starts to move towards the eye of the storm, something important happens. At latitude +12 degrees, this air travels only (2*pi*R*cos(12 degrees)) = 39,189 km every 24 hours, so its speed around the Earth's axis is just a little slower: only 1,633 km/hour instead of 1,644 km/hour. As it flows southwards towards the low pressure, it falls a bit behind in its eastward journey around the Earth's axis. If we look at the Earth in a co-rotating reference frame -- that's just a fancy term for saying "if we look at the Earth from a very tall tower stuck to the ground", we'll see this blob of air from the north come south .... and bend WESTWARDS. What's really happening is that it isn't moving quite as fast to the east as all the air at latitude +10 degrees, so, measured relative to this faster air, it appears to slide backwards to the west.

On the other hand, a blob of air which is closer to the equator than the eye of the storm, at, say, latitude +8 degrees, is initially moving a bit faster to the east than air at the eye itself. Hence, as this blob moves northwards to the low-pressure system, it appears to bend EASTWARDS; it gets ahead of the eye of the storm.

The net result is that the air flowing into a low-pressure system from far away forms a big circular rotating pattern we call a "hurricane", or "typhoon". The direction of rotation varies in the two hemispheres because air from lower latitudes will always bend eastwards as it heads towards the storm, but in one case, it bends south-and-east, while in the other hemisphere, it bends north-and-east.

Phew. Okay, enough about Coriolis forces. Let's look at your question.

Can this same force make it more or less difficult to turn a vehicle such as a motorcycle?

Well, if your motorcycle had wheels hundreds of miles in diameter, and if its spokes were not solid piece of metal, but a fluid .... then, yes, it might. However, since ordinary motorcycles are small and solid, and the difference in the rotational speed around the Earth's axis for the top of a wheel vs. the bottom of a wheel is a teeny-tiny fraction of the other speeds involved (like the speed of the drive shaft of the engine), Coriolis forces really don't affect their motion at all.