Designing a Great Bike Course

By the time athletes step up to the starting line at a triathlon, cycling event, or running race, months (or years) of planning has taken place to design the course they are about to undertake. As a racer one might not think about all the minor details of why a course is designed a certain way.  Course design is one of my favorite aspects of organizing races. It’s a time when I let my imagination run, and dream up a new half marathon, triathlon, or trail run. As an athlete myself, I’m constantly thinking of potential courses for new events as I run and ride in my daily workouts.

Let’s look at just a few features of a great bike course in a triathlon.  Specifically, let’s look at a course I recently lead design on for Ironman 70.3 Traverse City.

Bike ALL overview simple 1.jpg


First and foremost, athlete safety on race day is the most important factor.  This not only means using roads that aren’t dangerous, but also using roads that medical and other emergency services can access easily on race day.  For Ironman 70.3 Traverse City we ultimately opted to use roads that were larger and would have easier access in case of an emergency. This leads us to the next point.


About 2,500 athletes will compete at the 2019 Ironman 70.3 Traverse City race.  As a Traverse City native, I know all the great roads to ride on, and there are a lot.  With an event at this scale, however, we needed to figure out if those roads are capable of handling so many athletes on race day.  What is a super scenic route for a group ride of 20-30 riders, unfortunately isn’t necessarily a great route for a group ride of several thousand.  For this race, we chose a course with as few turns as possible, and roads that were as wide as possible.  By the very nature of what I’ve just said, these kinds of roads aren’t always the safest to ride on non-race days because they tend to be larger, wider, and busier roads.  But for race day, when the course will be closed to vehicle traffic, they are great.

Right Turns

The overall shape of the bike course for Ironman 70.3 Traverse City is a clockwise loop.  Why clockwise? Because if the course went counter-clockwise, athletes would be making more left turns, which means they would be crossing over (cutting off) a traffic lane every time they made a left turn.


Left Turn Scenario

Now, left turns can’t usually be totally eliminated, but we can reduce the number of them, and when they’re necessary, they can be placed in lower impact (traffic) areas.

Right turns are much more preferred options.


Right Turn Scenario


One of the trickiest parts of designing a great course can be achieving the exact distance that is needed.  Sometimes the courses work out perfectly, like the Olympic distance course for the Traverse City Triathlon, which is a perfect 40K clockwise loop course with no out-and-backs. For Ironman 70.3 Traverse City, we needed exactly 56 miles. I spent days looking over satellite maps on Google Earth, trying to find a perfect 56 mile single loop with as few left turns as possible. Eventually we realized that we would need to utilize a technique known as a “distance grab”, essentially an out-an-back section to add distance to a course.

InkedBike ALL overview simple 1_sketch.jpg

Ironman 70.3 Traverse City bike course distance grab

Because the course is a clockwise loop, the distance grab needed to be on the inside of the loop.  Again, otherwise athletes would be cutting off vehicle traffic when they turn left, and additionally they’d be cutting off racer traffic turning left back onto the main course. Here’s an imaginary example. You can see that cyclists would cross cyclists (yellow arrows) and cyclists would cross vehicles (green arrow).


Left turn distance grabs just don’t work

These are just a few features that race directors and planning committees think about when laying out a bike course (or run course). On top of these ideas, there are practical considerations like how will vehicle traffic be impacted and how that impact can be minimized. There are always going to be inconveniences to the regular flow of life when a race happens, but as race organizers we try our best to minimize inconveniences while creating a safe, challenging, and fun experience for racers.