What is Erg Mode?
“Erg” comes from Greek “ergasía” which means “work”. Erg Mode is a key feature of smart turbo trainers. Erg Mode communicates with the training app you are using, whether it is Zwift or a session you’ve built on your GPS device, and adjusts the resistance without the need for you to change gear.
Your power is how hard your press on the pedals multiplied by how many revolutions you complete per minute. Erg Mode ensures the power you create is adjusted based on your cadence. In erg mode you need only focus on your cadence.
When you are outside you use your gears to adjust your cadence and power as the terrain changes or to keep up with your group.
If you set your ride to be 200 watts with Erg Mode on, your trainer will adjust to keep you pedalling at that power. Or, if you are following a training session with power set at different amounts, the trainer will adjust as you ride.
Why Erg Mode it is great
1. You don’t have to think. If you’ve ever been riding on the turbo trainer, watching your favourite Netflix series and forgotten to follow the plan, Erg Mode won’t let that happen.
2. Complete a workout exactly as intended. If you struggle to maintain your pace, surge or back off, or feel like you're constantly adjusting your gears to hit a target, Erg Mode will allow you to get into a rhythm and pedal it out. This is great for building base endurance, recovery rides, or for mimicking a steady alpine climb.
3. You can’t quit early. If your training session has intervals of one minute plus, Erg Mode will help you stick to the target all the way to the end without shifting down or slowing your pedalling.
4. It helps with recovery rides. Pedalling at lower intensity is harder than it sounds. You will often find that pedalling a cadence that feels comfortable creates too much power while choosing an easy gear sends your legs spinning at 120 rpm. Erg Mode helps you keep a good cadence without overdoing the power.
How does Erg Mode work against you?
1. You can end up in the spiral of death. If you start to fatigue and your cadence drops outside a comfortable range, Erg Mode will increase the resistance to maintain average power and this puts even more load on your legs. You slow further and end up grinding to a halt and don’t complete your interval to the true level of your ability.
2. Erg mode reduces your ability to change cadence quickly, sometimes called your ‘jump’. You need to be able to quickly change your cadence for fast acceleration. You’ll often use it in the real world on a short, sharp climb in the real world, moving away from lights, overtaking other road users
3. It decreases your real world pacing skills. Erg Mode is doing the work for you and therefore you don’t practise skills like pacing, mental strength, gear selection and cadence control.
Erg Mode Top Tips
Mimic climbing use the small ring
Erg Mode will work in any gear on your bike with no shifting required. If you want to work on your climbing, ride in the small ring on the front. This will reduce your trainer’s inertia, mimicking the feel of a low-speed climbing effort where your muscles aren’t able to ‘coast’ as long at the top and bottom of each pedal stroke.
Change gear to ease wear
If you ride a lot with Erg Mode turned on, try to vary your gearing in order to wear your cassette more evenly.
Remember your chainline
If you have an extreme chainline, your trainer and bike may allow you to ride within an extreme line. You will increase wear on the chainset, chain and cassette as well as decrease your power. If you are in the big ring on the front, try not to pedal in the easiest gears for too long at the back.
Stay smooth to ride out of the spiral
If you sense the spiral of death beginning, your cadence dropping and resistance increasing, unfortunately the only way out of the spiral is to push harder and increase your cadence. Shift into an easier gear and smoothly raise your cadence. Don’t jump out of the saddle and start sprinting. The trainer will then adjust the resistance.
Sprinting? Toggle Erg Mode off
Turn off Erg Mode before or during your session if you have a section of sprints that are between 10 and 30 seconds. Locate the Erg Mode on/off toggle on your training app and make sure you can reach it. If you sense you are entering the ‘spiral of death’ you can toggle it off to complete your session.
When building up to the start of an interval gradually increase your cadence and ride smoothly. It will allow Erg Mode to adjust resistance without jumping your cadence and resistance.
Tired? Toggle off Erg Mode
Feeling tired? Turn off Erg Mode or reduce your power target. Erg Mode is smart but it isn’t smart enough to recognise you are tired. This can be detrimental to your training session as well as demotivating. Let your smart trainer play dumb and get reacquainted with your shifters.
Turn off Erg Mode when testing fitness
Turn off Erg Mode in your training app when completing an FTP test or training app fitness test.
Turn off Erg Mode when riding high or low cadence
Turn off Erg Mode if your session focuses on anaerobic power, cadence skills, or involves riding at extreme cadences, e.g. 50 rpm or 100+ rpm. Cadence sessions focus on your ability to improve pedalling efficiency rather than hold a specific power. For a cadence based workout you'll be working within a fitness bracket and Erg Mode doesn't allow for that.