If you do a custom workout with a smart trainer in Zwift, you may have the option to use ERG mode. ERG mode allows Zwift to take control of your trainer’s resistance and adjust it to help you reach your target watts regardless of your cadence and course terrain. In this post, I will walk you through how to enable ERG mode and some things you need to pay attention to when using certain smart trainers.
HOW TO ENABLE ERG MODE
To enable ERG mode in Zwift, the first thing you need to do is pair your smart trainer as a controllable trainer in Zwift PAIRED DEVICES menu. This allows Zwift to take control of your trainer’s resistance and automatically adjust for each interval.
Before we go any further, let’s go over a little feature referred to as “Power Match”. One of the best features of smart trainers is their ability to provide power numbers. But what if you have your own power meter and you prefer to use your power meter instead?
Power match is when the software you are using – in this case Zwift – read data from your power meter rather than the smart trainer and adjust resistance based on the data it’s receiving from your power meter.
To enable power match, all you need to do is pair your power meter as the power source in Zwift’s PAIRED DEVICES menu as you see in the screenshot below. That’s it!
If ERG mode is available for your type of trainer, you will see the ERG Mode option in the workout selection screen. Make sure that box is checked before starting your workout.
WHEN IN ERG MODE:
- You will no longer feel course gradient changes. This is important to understand. When in ERG mode, Zwift will ignore any changes in course gradients. It will only adjust resistance according to your intervals. However, it will still calculate your speed based on your power and take course terrain into account.
- Your trainer will automatically adjust the resistance to reach your target watts. If the interval calls for 200 watts, the trainer will increase resistance until you reach 200 watts regardless if you pedal at 120 rpm or 50 rpm. The slower your cadence the higher the resistance.
- No need to shift gears.
ADJUSTING WORKOUT INTENSITY
Zwift allows you to adjust workout intensity when in ERG mode. If you are having trouble hitting your intervals you can lower the intensity by up -10%. If you are having a good day, and the intervals feel too easy, you can increase intensity by up to +10%.
To adjust workout intensity:
- Use Zwift Mobile Link app. In the map screen, only when in ERG mode, you will see an up/down arrows buttons. These arrows will allow you to adjust the intensity accordingly.
- On iPad/iPhone, tap the screen and a menu will appear from the bottom of the screen. You will see up/down arrows that you can use to adjust workout intensity.
- On Apple TV, using the remote control, swipe up and a menu will appear from the bottom of the screen. You will see up/down arrows that you can use to adjust workout intensity.
- On a PC, click the arrow up button on your keyboard to bring up the bottom menu. You will see up/down arrows that you can use to adjust workout intensity.
HOW TO DISABLE ERG MODE IN ZWIFT
If you would like to disable ERG mode in the middle of a workout, simply tap the screen (or swipe up the Apple TV remote) to bring up the bottom menu and tap the ERG ON button and Zwift will disable ERG mode. You can turn ERG mode back on by bringing the bottom menu back up and tapping the ERG OFF button to enable ERG mode.
ERG MODE vs RESISTANCE MODE
When ERG mode is disabled or if ERG mode isn’t available for your type of trainer, Zwift will switch to resistance mode. In resistance mode, you have full control over resistance. You can adjust resistance by either shifting gears, or adjust resistance by using the same arrows in Zwift Mobile Link app or the bottom menu. Simply, tap the up and down arrows and that will adjust the trainer resistance without having to shift your bike gear.
ERG MODE WHEN FTP TESTING
If you are doing an FTP test and you have ERG mode enabled, Zwift will enable ERG mode during the warmup and cooldown parts only. When you enter the 20-minutes interval, Zwift will disable ERG mode and turn on resistance mode and allows you to manually adjust resistance. The whole idea of FTP testing is to find your ability to sustain the highest possible power you can sustain during a set period and using ERG mode can be problematic.
If you find yourself running out of gear during the 20-minute test segment, you can use the up/down arrows in the Zwift Mobile Link app to adjust your smart trainer resistance.
ERG MODE AND TACX NEO
One unique feature the Tacx NEO has is road feel. This allows the Tacx NEO to simulate different roads such as dirt, cobblestone, gravel, wooden boards, etc. You can enable this feature in Zwift in the settings menu.
When the Tacx NEO is in ERG mode, Zwift will disable the road feel feature altogether. However, if you are in workout mode and have ERG mode disabled, Zwift will enable road feel – if you have road feel enabled in settings – and you will feel the resistance increase if you hit a cobblestone section for example. This can be problematic if you are FTP testing or holding on dear life during the last few minutes of a hard interval and you suddenly feel the resistance increase.
If you decide to disable ERG mode, you might want to also disable You can disable road feel. You can access road feel setting in Zwift’s menu under settings.
Some trainers such as Wahoo KICKR and SNAP offer power smoothing. If enabled, it will make the reported power very smooth and doesn’t show the small inconsistencies with a user’s pedal stroke. This functionality will not impact the way the trainer work or effect ERG mode in any way. It’s only a display function.
Power smoothing is on below. Note how smooth the power graph is:
Power smoothing is off here. You can see little variances in the power graph below:
ERG mode is my personal favorite. Set my desire target watts and let the trainer adjust to keep me honest during training.
Thanks for reading!