Suffer Speed - Understanding Speed And Distance Calculations



What Is Suffer Speed?

We have created a formula that uses some simple physics equations to calculate speed from your power data. We use Suffer Speed to calculate the distance for your ride.

How Does The Formula Work?

We are starting with a simple model that calculates instantaneous speed from power. Here is what we use to calculate it:

  • Current Speed - From the sensors you have connected to The Sufferfest (when applicable)
  • Power Output - From your smart trainer, power meter, or virtual watts setup
  • Rider Weight - From the settings page of The Sufferfest app
  • Bike Weight - 9kg
  • Rolling Resistance - 0.005
  • Head Wind - 0kph
  • Temperature - 0 C
  • Elevation - 0 Meters
  • Position - Hands on the hoods


How Does This Affect Me?

  • If you have a power meter that doesn’t report speed, this means that your rides will now show as having speed and distance in other apps.
  • If you have a power meter, smart trainer, or Virtual Watts trainer, the speed and distance reported in the .fit file to other apps will now use virtual speed.


Why Did You Change How Speed And Distance Were Being Calculated?

We are adding this virtual formula in an effort to create more consistent speed and distance data no matter what equipment you are using.  Some users (with power meters) have never been able to show speed or distance when using The Sufferfest App.  Other users with smart trainers end up with some pretty crazy speed numbers.  It is difficult to go in and address each of these specific situations so instead, we have found a way to level things out a bit.  As we gather more data we will continue to improve the way that this formula works.

Can I Disable Suffer Speed?

Desktop (Mac and Windows) users can disable Suffer Speed.  iOS users can not... yet.  We will add this ability in a later update.

How Do I Disable Suffer Speed?

Open the device connections menu.  

You will notice that Suffer Speed is enabled by default.


Now click the speed icon next to your smart trainer or speed sensor


Now the app will use the speed supplied by your smart trainer or speed sensor instead of Suffer Speed.


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