- Before we actually start creating our model,
we're just going to quickly go over the anatomy of a bike.
So we all know we're talking about the same things.
If you're a bike enthusiast,
then you probably know a lot of this already.
So apologies if this seems quite obvious.
But different parts of the world,
and even different sub-areas of cycling
have different terms for the same things.
So it's good that we all get on the same page
at this early point.
So let's take a look at a typical bike, something like this.
We'll mainly focus on the frame
because that's what we'll be creating.
Most modern, rigid bikes
are based on this diamond frame layout,
made of two triangle shapes.
The front triangle or main triangle can be found here.
And for many bikes, this isn't technically a triangle,
because it has this small foreside.
But we still call it triangle because of the rough shape.
The front triangle is made up of the top tube,
as the name suggests that's up here at the top,
then we have the seat tube.
This is where the seat post,
where the seat attached fits into.
Then down here, we have the large down tube,
and then at the front, there's a smaller head tube.
At the back, we've got the rear triangle,
sometimes called the paired rear triangle
because it's actually made up of two,
almost identical triangles that hold the back wheel.
The rear triangle is made up of the seat post on one side,
so the seat post is shared
between the front and rear triangles.
Then we have the chain stays along here
where the chain runs,
and the seat stays that go up to the seat post.
Where the seat stays and the chain stays
join together down here
where the axle of the wheel is held
is called the rear dropouts.
These are the parts that the rear wheel fits into.
At the very bottom of the frame, down here,
where the down tube, the seat tube,
and the seat stay all join is the bottom bracket.
This is a very important part
because it's where the crank set attaches.
This is where the front chain ring
and the pedals will rotate around.
Then there are a few more details.
At the back, obviously we've got the rear wheel.
This might also have gears and brakes.
Moving forward we've got the seat
that's attached to the seat post
and that fits inside the seat tube.
At the front of the rear triangle,
we've got the small head tube.
This is where the front fork and handlebars usually attach.
The front fork holds the front wheel,
and it might also have breaks attached.
The fork goes through the head tube using a headset,
which is usually some collection of bearings.
But we don't really need to know
details of that for this course.
Then on top of the head tube,
the top of the fork is usually attached to a stem.
That clamps the fork in place within the head tube,
and it also allows the handlebars to attach,
which obviously allows for controlling of the bike.
So that was a quick overview of a typical bike.
We'll be refreshing these names as we go through,
so don't worry if you don't remember all of them.
But the main ones to try to keep in mind
are the front triangle, with the top tube,
the head tube, the down tube, and the seat tube.
And the rear triangle with the seat stay, the chain stay,
and the seat tube.