There’s a new tool on the ride page for optimising time trials. It is powered by Best Bike Split, which boasts a “math and physics optimization engine takes your power data, course info, and race day conditions into account to give you the perfect power plan to hit your best bike split ever”. (Don’t worry, you don’t need to be a triathlete to use it, for it works equally well for regular time trials.)

It works by taking a ride you have ridden, and then working out what the power output for each section of the ride should be to give the fastest time for the course that you can achieve. This tool can be found at the bottom of ride pages, along with the other ride analysis tools (it’s listed as “Best Bike Split”). The first step is to enter some details about yourself, your bike and the course. The details in the “rider” and “equipment” sections are saved (when “Calculate” is clicked) so you don’t need to keep changing them, and weight, FTP and temperature are automatically filled in. Goal wattage is by default the effective power of the ride.

Once that is done, click “Calculate” and wait a little while (it can take up to a couple of minutes the first time for long or complex courses, although it’s much faster the second time if you want to change some settings). A table will appear which shows the theoretically optimal power output for the ride.

Best Bike Split works by dividing the course into segments that should be ridden at a constant power output and calculating what that power output should be to give the best overall time. This table shows each segment along with the calculated results (on the left, in the “ideal” columns) and the actual data from your ride (in the “actual” columns). Segments (i.e., rows) can be clicked on and they are shown on the map and in the main ride chart.

A few caveats are in order:

This tool only works for rides that you have already ridden. If you know the course of a time trial you are going to ride without having ridden it, you can create an account on Best Bike Split and produce a power plan from there.

This tool only produces meaningful results for time trials or similar rides. It is unable to take drafting (from other cyclists, cars, motorbikes) into account and will often say the optimal result is slower than the actual ride.