A "smart" ("electronic") bike trainer has electronic features that allow riders to choose how they would like to work out: with resistance that's controlled automatically, or resistance controlled manually a la a mechanical trainer. This can be accomplished using two modes. The terminology for each mode differs between manufacturers, but the functionality of each mode is the same. Let's dive in...
Note: TrainerRoad will display the modes that are supported by your trainer when you pair your trainer.
ERG Mode (Resistance Control Mode)
This is the most commonly used mode. TrainerRoad can automatically control the trainer's resistance in accordance with the workout's profile while in ERG mode. There's no need to shift in this mode as the resistance will change automatically, and we recommend keeping a steady and easy-to-hold cadence throughout the entire ride (unless workout instructions tell you otherwise or you need to "ramp up" your pedaling for a tough interval).
Tips when using ERG mode:
Gearing can affect the nature of your workout. Follow these gearing tips when completing a workout in ERG mode:
Set your gearing - In order to maintain smooth, even power across all of your power zones, you should maintain a mid-ring gearing in the rear cassette, and either a mid (if you have three) or inner (if you have two) front chainring. Your chain should follow a straight path from rear to front. This will also help you avoid hitting a wattage floor. When in doubt, check your Trainer's manual for their recommended gearing settings or reach out to us.
Mid-gear in the rear cassette
Inner chainring in the front
Maintain your gearing - In most cases, you should not change gears once you've set your gearing. Changing your gears may confuse your smart trainer and can result in a temporarily uneven delivery of resistance.
Cadence can directly change your output power during your workout if you're changing your RPMs significantly (e.g. >10-15 RPM). When increasing your cadence, your power will attempt to rise; to counteract this, your trainer will lower the resistance. The opposite will occur when lowering your cadence; an increase in resistance will be felt.
Anticipate upcoming intervals by slowly ramping your cadence before the interval begins. You should ramp to your desired cadence that you'd like to maintain during the interval. This will help you be able to manage the upcoming change in prescribed power.
Maintain a steady cadence - With the exception of the previous point, it's recommended to maintain a constant cadence within a range from 80-100 rpm during your workout. This is the best practice unless otherwise stated in the workout description and/or text.
For even more information on ERG mode, click here.
Resistance Mode
This mode mimics the functionality of a magnetic trainer with a linear power curve. This mode includes a variable resistance setting that can be electronically adjusted.
Tips using Resistance Mode:
Changing Gears
When using resistance mode, you'll need to change gears as you typically would while riding outdoors. To reduce wear on your trainer, try to select your gearing that limits cross chain as much as possible. This will also keep you riding as quietly as possible indoors.
Finding the right Resistance Percentage
You may find that the "default" resistance percentage of 50% that many trainers default to is far too high to actually train at based on your gearing - it might be impossible to turn the pedals. If you plan on using Resistance modes, we highly recommend finding the right Resistance mode percentage before starting your workout.
If you use the TrainerRoad desktop app, you can use the left and right arrow keys to adjust the Resistance mid-workout.
Standard Mode
This mode mimics the functionality of a fluid trainer with a non-linear, exponential power curve. This mode includes a variable resistance setting that can be electronically adjusted.
The major advantage of the Fluid Power Curve (Standard Mode) is that one setting can cover a wider range of wattages. Since the curve ramps up, the maximum power you can generate in a giving setting is greater than the Magnetic curve (Resistance Mode), which can be seen in the graph.
Shown above is a power curve of magnetic and fluid trainers. Resistance Mode mimics the linear power curve of a magnetic trainer while Standard Mode mimics the non-linear curve of a fluid trainer.
Our Recommendations
For most training sessions, we recommend using ERG mode. In this mode, smart trainers constantly adjust resistance to match TrainerRoad's target power - no shifting or cadence adjustments necessary. ERG mode allows you to focus purely on the workout at hand.
That said, there are a few special cases where using ERG mode is not recommended.
1. FTP testing intervals on an 8-minute or 20-minute FTP Test
Test intervals inside of one of an 8 minute or 20 minute FTP test will need to be done in either Standard or Resistance mode. Since these intervals should be done as hard as you can, we don't want ERG mode limiting your power output. Don't worry though, TrainerRoad will automatically switch your trainer out of ERG mode during test intervals.
Note: The Ramp Test used to calculate FTP can be completed in any mode, but ERG mode is recommended.
2. Sprint intervals
ERG trainers perform a brief ramp up to an interval’s target power. For longer, less-intense intervals, this ramp-up is hardly noticeable. However, this ramp is more pronounced for short, high-intensity intervals. If an interval is under 30 seconds, riders may want to consider riding in Resistance mode to avoid any lag time in reaching their target watts.
Changing Modes on Mobile (Android & iOS)
Before starting your workout
- First pair your device under the Device tab.
- Once paired, tap on your trainer to bring up the device settings.
- From this page, you can now change between your trainer's available modes.
During a workout
- Tap the devices button in the bottom right-hand corner of your workout screen.
- This will take you to the Device Quick Actions menu.
- Tap Smart Trainer to initiate a spindown calibration
- Tap Power Meter to initiate a zero calibration.
Changing Modes on Desktop (Windows & Mac)
Before starting your workout
- First, pair your device under the Device tab.
- Once paired, tap on your trainer to bring up the device settings.
- From this page, you can now change between your trainer's available modes.
During a workout
- From the bottom toolbar, click on the menu showing your current mode.
- From the menu, select your desired mode.
- Use the slider to the right to adjust modes (if applicable).
- Then continue to ride!