How To Draw A Bike Frame

Details
Category: Ebikes
The technique is to create a base line sketch first with the basic point to point dimensions. Then project these lines onto a centreline sketch where the complex profiles are drawn for each part off the frame. This way if the baseline sketch is changed the other parts will automatically change.

00:00 Intro
01:07 Step 1 - Base sketch
04:32 Step 2 - Centerline sketch
08:33 Step 3 - Draw headtube
12:19 Step 4 - BB ST
14:47 Step 5 - Front triangle
18:49 Step 6 - CS centerlines
22:14 Step 7 - Tyre clearance body
23:45 Step 8 - SS centerlines
27:46 Step 9 - CS body
29:36 Step 10 - SS body
31:20 Step 11 - Joining the dropouts and yoke
34:59 Step 12 - Conclusions

 

1 Base Sketch 

 Simple Baseline sketch.

 

 

 

 

 

 

Create/Dimensions

1 DownTube 690
2 Seat Tube  440
3 ChainStay  430
4 SeatStay
5 TopTube
6 HeadTube 110
7 HeadsetStack
8 AxleToCrown
9 AxleToAxle
10 AxleToGround (half wheelsize)
11 BottomBracketToGround
12 BottomBracketDia

Sketch should now be black (fully defined)

2 Centreline Sketch

Create a new Centreline Sketch. Project onto this sketch the lines from the base sketch that are exactly on the centreline. In this example they are the Downtube(1),SeatTube(2),TopTube(5) and HeadTube(6).

Simple Centreline Sketch

 

Draw and dimension up from the origin

1 Downtube
2 SeatTube
3 ChainStay

Connect the:

Seatstay (4) from the SeatTube(2) to the Chainstay(3) and dimension
TopTube(5) from  the SeatTube to the DownTube(1) and dimension.
Downtube(1) to the TopTube(5)

Draw and dimension the HeadTube (6)
Constrain the centre of the HeadTube perpendicular to to the TopTube (5)

Draw and dimension HeadStack(7)collinear with HeadTube(6)

Draw and dimensiion the AxleToCrown(8)

Join, constrain horizontal and dimension AxleToAxle(9)

Draw construction lines AxleToGround(10) perpendicular from the  AxleToAxle(9) to Ground

Draw and dimension perpendicular construction line from the BottomBracketToGround(11) to Ground

Dimension the BottomBracketDia 

The sketch should be fully defined now.

Project

Head Tube
Seat Tube
Chainstay

from base sketch

 

Create offset for top tube

crostube_front_offset 25
crosstube_rear_offset 50

Create offset for down tube

 

 

3 Draw Headtube

Insert new component HeadTube

Create a new sketch on this component.
Project line from centreline sketch onto new sketch for the centre axis of the head tube. Change linetyope to centreline
so that it dimensions as a diameter

Create a rectangle for the head tube. 
Add lines for inner diameter.
Dimension
head_tube_outer 48
head_tube_inner 44

Add reinforcement rings here if necessary

Use a revolve to create the headtube

 

4 Draw the bottom bracket in the seat tube.

Use a plane along a path to 

Draw the seat tube

 

 

Add down tube
Add  top tube (cross tube)

5 Chainstay

Construct a plane at angle about the chainstay centerline