EZ Disc Gradient & Speed Graphs Explanation

EZ Gains has taken examples from 100s of time trial and triathlon courses, we are giving you examples below on some of the hilliest triathlon courses over a range of cyclist weights, the facts are that no matter how fast or slow beginner amateur or pro, road bike, TT bike you all gain a huge amount of time savings when adding an EZ Disc. "IF" going faster is what you are trying to achieve then an EZ Disc is a MUST, it’s as fast as a disc, similar weight at a fraction of the cost. It’s a myth that you have to travel a certain speed for aerodynamics on your EZ Disc to work, your CDA is your CDA "Drag Coefficient multiplied by area". It’s also a Myth that using just a deep rim on hilly routes will be faster than a wheel + EZ Disc.

EZ Disc + Wheel is Faster then just a wheel on a Triathlon Course:

EZ Gains have gone to great depths to show adding a 500g EZ Disc on the hilliest Triathlon courses, will still save you a huge amount of time over opting for just a deep section wheel. This could be a costly mistake in chasing your goals over a triathlon course. It is pure MYTH that the weight saving will save you enough time on the hilliest route to outdo the aero benefits and reduction in CDA, over the duration of the whole course. From many examples we looked at, we focused on the Ironman Marbella 70.3 course, with 1474 metres of elevation over 90k and the data concluded savings of over 2 minutes in all variations we looked at.

Please see some examples below.

The first step to making the graphs is to define the parameters and derive the equation. The main assumption is that there is constant speed – e.g. for each calculation there is no acceleration. In this case, the main forces acting against a bicycle are the aerodynamic drag force,rolling resistance force and gravitational force.

Opposing this is the pedal force that the rider exerts through the cranks, which transfers through the drivetrain, then eventually through the rear wheel to the ground to push the bicycle forward, by which time the force would be slightly lower, due to frictional forces – this is accounted for with efficiency. We can now define the basic force equation:

The next issue is that pedal force (Fped) is not commonly measured. In cycling, power is mostly used instead. To get power, we can multiply by velocity (v) as P = Fv. Since Fped has been multiplied by v to get Pped, so should everything else to balance the equation:

The final step is to address the cos Ø and sin Ø which relate to the slope with angle Ø.

In cycling, gradient percentage is used to describe slope angle, not radians. Therefore, cos Ø and sin Ø should be converted to functions of gradient, which we will call ℎ:

Now we have tan Ø, we can use trigonometric identities to get cos Ø and sin Ø. Resulting in: