The basic idea is to visualize each motorcycle ergonomics. So we take a look at how the lines represent body position and some examples of the issues brought by basing it on photographs.
One cool way to use it is to compare a bike that you are used to, with a bike that you are interested in, but you have to take these limitations into account.
The lines
- Red lines: horizontal red line is the lowest usable, visible part of the seat and center of the image, vertical red line is the center of the image;
- Green lines: horizontal green line is the inner highest point of the grip, vertical green line is the furthest point of the grip from the seat;
- Yellow lines: horizontal yellow line is the top of the foot peg, vertical yellow line is the center of the foot peg;
- Grey lines: spaced 10 centimeters from each other in each direction, vertical dark greys over seat and grips.
When you compare two to four motorcycles, all of them are aligned by the seat, so you see the difference in distance from your behind to your hands (green lines) and to your feet (yellow lines).
The issues
The first issue I noticed was when I made the images for the Size Estimator of the two versions of the Harley Heritage Classic, which are the same bike with different displacements. It presented two clear issues: the pictures for the 107 and 114 models had different angles, visible for instance by the difference on the floor boards; also, it’s evident that they have the handlebars on different inclinations, thanks to the tallish mini apes they use, affecting the green line that shows hand positioning.
Today I noticed that the BMW S1000XR looked like a monster beside its siblings, the S1000R and S1000RR. The XR is a Sport Tourer and indeed bigger than the naked and sport versions, but it looked weird, so I went deeper on their specifications and noticed that its wheelbase wasn’t that longer. Also, after adjusting for the wheelbase on the Sized Estimator, I noticed that the indicated height made sense. So I decided that the length we see on the BMW website must be wrong, a typo or something. Now it makes sense visually and we see an “estimated” length listed here.
Also, if you know how all the brands measure seat heights let me know. We do it at the lowest usable section visible in the picture, but different designs and foam density make the real lowest part a mystery.