Or is there both liquid and air cooled in one

My cousin is a bike rider and i'm planning on getting a Dual Purpose, so i ask him all the bike stuff. I remember he said all the racers use liquid cooled, but instead of antifreeze, use mineral water and some kind of salts, again, how the races do. the downside to the water is you gotta drain you rad in the winter so you don't blow you pipes

Liquid cooled is far better for have a bike just to ride. Requires no more maintenance than a car.

No brainer - liquid of course.

Liquid cooled engines simply even out their temperature variations better avoiding getting hot more often than air cooled engines.

An example of this is if you get caught in traffic on an air cooled bike you loose the air flow over the engine and it starts to get hot to the point where you can feel the heat rising off it.
This of course puts added strain on the engine over it's working life.
Bear in mind though that air cooled bikes also tend to have a small oil cooler that helps mitigate some of this.

A liquid cooled bike would be able to even the hot spots out slightly more but don't for a moment believe any of this rubbish about it being the same as a car....it still needs the air flow created by moving because a car has a fan that kicks in when stationary....a bike doesn't.

Overall the liquid cooled engine does get stressed less so long term it should help with reliability.

In theory at least.

I say in theory because like many things it doesn't seem to make any real difference in the real world.
There are many other factors that influence reliability that are far more likely to have an affect than how your engine is cooled and those factors tend to have those affects well before your engine packs in from having got too hot a few times.

The trick is not to get stuck in traffic and to be aware of how hot the engine is getting if you do.....if you simply sit there and let it cook to death then sure, it will do.

So don't....try and keep moving. If you can't and are stuck for a while then turn it off.
Remember though, without a fan a liquid cooled bike still needs some air flow so standing still makes it get hot also.....it just takes a bit longer is all.

The one big advantage of an air cooled bike of course is that nothing can go wrong with the liquid cooling system that it doesn't have.
It can't freeze up if the anti-freeze gets low and you can't get a leak and loose all your coolant.

Sometimes simple has it's place in the world.

We have two bikes, one air cooled and one water cooled.......both seem to work fine.
Over the years though we've had far more air cooled bikes.

I do have one small piece of assistance fortunately.....I moved to England from the US a few years ago and here we rarely have to stop for traffic.....lane splitting, "filtering" they call it here....is legal.
If you can't pass stopped traffic then that increases the problem but the principal is exactly the same.