How To Draw A Bicycle
Drawing a bicycle is hard because all angles on a bicycle are wrong
They are wrong of course only in the sense, that they are not what we think they are. Not knowing these stubborn little wrong angles is what makes drawing a bike such a nightmare. This is why I want to go over all the things I have learned in several years of being mystified by the process of drawing bicycles.
Drawing a bicycle is no trivial thing. Draw me a bicycle and I know who you are. You are probably funny.
I know I am in danger of spoiling this small personality test forever*, but the clients have been complaining and some may have even been handing round your sketches in the break-room for a good laugh. That is why you are here.
*As a substitute for this personality test I would recommend this: Draw me a map of Europe!
But back to bicycles. Naturally, we just get into the basics. We are going to draw a common, semi-sporty bike in a side view. We are simplifying of course because the third dimension brings quite a few more wrong angles to the table (as it usually does). The idea is to get a grip on bicycle geometry and the reason why it is the way it is. Once we know why it is that way, we will remember it next time we draw it.
If you do not care about reasons and just need a quick how-to, jump to the end of the article, where I tell you how to draw a bike in four simple steps.
When we think of the basic geometry of a bicycle, we can simplify it to two connected triangles and a stick. (A) This type of frame is called a diamond frame. The drawing in (A) is super-simplified. The following is a walkthrough of how to make this into a proper bicycle frame.
First problems arise when we add wheels to our frame. (B) The front wheel, if about the same size as the rear wheel, will touch the down tube in our construction.
A common fix for this is, to simply draw rather small wheels, which makes the bike look … well, unrealistic. Especially the rear part, which looks now weirdly elongated.(C) And no, don’t tell me it looks like a BMX — it doesn’t.
What we need to understand is that the fork holding the front wheel is angling forward, which creates sufficient room between the down tube and the wheel. (D)
On some bikes, the fork does not meet the wheel at the center in a straight line, but rather bends towards it in a nice little curve at the end. (E)
Success! We have a bicycle, with two wheels that have enough room to turn.
To get even closer to a realistic bicycle we will need a few more ingredients. Here it comes: the horizontal tube holding the rear wheel — the chain stay — is usually angled slightly upwards. (F) I humbly admit: this is a detail that escaped my notice for years.
This angle allows the pedals to be just a little bit lower to the street. A person can now sit on the bike, and have his or her almost stretched out legs resting on the pedal at its lowest point (G).
Now that you got the hang of these things your discerning eye tells you: It just does not look right, yet. Let’s continue logically.
Imagine you are the figure in (G). You had enough of enjoying the view from your bicycle. Also: having both your feet on the pedals you start listing dangerously to one side — you better get going. Let’s go, let’s drive!
As soon as we try to push the pedals, things are getting awkward. Why can’t we create proper forward momentum? Why is this so hard?
The reason is, that the chain ring and crankarms are straight below our sitting position. It is hard for our feet to push the pedals forward. In other words: because we are on top of the pedals we cannot get our weight behind them. Behind them — that is the clue here.
To remedy this, our body needs to sit further back on the frame, and for that to happen the seat tube needs to be angled backwards. (H)
In this position, our legs are at a better angle to actually put pressure on the pedals as they revolve down on the front side.
On a side note: the chain connects the chainring and pedals to the rear wheel, not to the front wheel or even both. Apparently, this is not a trivial thing — 12% of non-cyclists couldn’t figure this one out even with a real bicycle in front of them according to this study.
Having placed the saddle backwards in (H), we notice that the position of the handlebars is now further from the driver. He or she needs to sit bent over or be in possession of a set of very long arms to grab them. On older style bikes the stem (the angled tube holding the handlebars) may go backward towards the saddle (H), but on most modern bikes it goes forward. This allows for more effective steering.
The problem is the meeting point of the top tube and down tube under the head, see (H). They are not simply forming a tip of a triangle. Instead, they are both connected to another tube which our frame is missing up to this point entirely.
It is called the head tube and it connects the head (handlebars etc.) to the fork of the front wheels (I). This short piece of tube is usually parallel to the seat tube. Note how now our head can go forward without being too far to reach.
The top tube can be parallel to the ground but sometimes is also lower on the side of the saddle. (J)
Now comes the good news: when you have reached this part of the drawing, there is some room for adjustment (cheating), by varying the height of the seat and the handlebars to make a person fit on it. This can also hide minor defects in your construction up to now.
In a realistic setting, you should be aware of the fact that the handlebar is usually not higher than the saddle. On mountain or trekking bikes the seat and the handlebars are often at an equal height. On racing bikes, the seat is usually even higher than the handlebars. Generally: the higher the seat and the lower the handlebar, the sportier the driving position (K).
Finally, a quick step-by-step how I would recommend drawing a bicycle:
1) Start with the wheels. Make them even sized and leave less than one width of a wheels diameter of space between them. (L)
2) Draw the seat tube and the head tube. (M) Remember to angle them backwards and to make them parallel. The head tube should be pointing towards the center of the front wheel, or slightly behind it if you prefer the curved-fork-type. The seat tube should be close to the rear wheel and extend a bit below the height of the wheel centers.
3) Draw the top tube and down tube. (N)
4) Last, simply connect the existing frame to the center of the wheels. The seat stay and chain stay connect the rear wheel and the fork connects the front wheel. This gives us our basic frame. (O)
From this basic diamond frame, a lot of different bicycle shapes can be derived. For example the nifty BMX style below. Maybe we have a look at that another time.
Congratulations: you have successfully drawn a not too implausible bicycle. It might even support a little person on it, without resorting to ergonomically strained positions or extremities of unbelievable dimensions.
Next time: how to draw a map of Europe.
Daniel Stolle is a professional illustrator living in Finland.