The common statement when doing an ERG-based workout (on a smart-controlled trainer) is to “never shift.” You simply find a gear you like then “set it and forget it” for the entire workout. The beauty of the ERG workout is that it increases or decreases the trainer resistance as your pedaling cadence changes, with the goal of maintaining the target power.
Gearing may be selected based on a variety of factors:
- Pick any combo that provides a straight chain line in order to reduce drivetrain wear.
- Pick a low gear to keep trainer noise low.
- Pick a low gear to provide low flywheel energy to mimic lower momentum riding like hills or off-road.
- Pick a high gear to provide high flywheel energy to mimic higher momentum riding like flats or smooth road.
Standing Efforts
“Set it and forget it” is nice, but a slight problem exists when it comes to standing pedaling efforts in ERG workouts. Standing pedaling is usually done at slower cadences than seated efforts (other than sprinting). Typical seated cadences range from 85-105 rpm, while standing cadences range from 55-75 rpm.
The conventional wisdom on ERG mode means you simply slow your cadence until it is where you want it to be (say 65 rpm) then stand for your effort. The problem with this approach is the large drop in workout power that happens when you slow your cadence. It happens before the trainer resistance increases back to the target power. That power decrease is a change from the desired target of the workout and less than ideal.
Additionally, when you return to the seated position, you must increase your cadence again (say 90 rpm). This causes a large increase in measured power until the resistance adjusts back down again.
Improved Standing Efforts
The solution comes from adopting the normal process used when standing outside. Generally, when you stand outside, you want to shift up a few gears (say 3 harder on the cassette). The higher gear keeps the wheel speed, but allows for the slower pedaling cadence.
So you can do the same thing while riding inside, even in ERG mode. The upshift keeps the “wheel speed” on the trainer, but keeps the ERG resistance nearly unchanged. The trainer will still adjust as needed, but the upshift makes that trainer adjustment much smaller.
Try this during your next ERG workout. Get into an interval at least 1 minute long, then:
- Ride seated at 90 rpm cadence, using your desired gear combo. Make sure to allow at least 3 up shifts on the cassette or use the small chainring.
- When you are ready, shift up (3 on the cassette or the big chainring) and stand up. This shift drops cadence about 25-30 rpm depending on the difference between your specific gearing.
- Perform the desired standing effort and adjust cadence slightly as desired, just like normal ERG riding.
- When you’re ready to return to a seated and faster cadence, sit down and do the opposite of your upshift. Resume your prior cadence and continue your workout.
Using this shifting technique removes the need for the trainer resistance unit to adjust as much as it otherwise would. You keep the power much closer to the target for the entire interval, including the standing to seated transitions, which maximizes the workout overall.
Your Thoughts
Do you shift in ERG mode? If so, why and when? Share below!
Thanks man! Have thought about it many times but didnt want to disturb mr erg, Will try it my next workout
Happy to offer the suggestion. Let us know what you think once you give it a try. Happy training 😀
I’VE always rode in ERG mode and treated the same as riding outside,I had the original Tacx Fortius,shifted when necessary,I think is a no brainer!
I agree that it makes sense when you think about it. I shared the tip since there are several places that use the “set it and forget it” gearing suggestion. And they just say to slow down and speed up cadence to deal with these low cadence standing efforts.
But I think that leads to issues and can be done better by simply adopting the same shifting practice that we already employ while riding outside. Great to hear that I am not alone in that realization 😀
Thanks for the article. I’ll try this method next time, instead of my usual way of switching ERG off, hammering the low cadence/high watts effort out, then switching ERG on again.
Swapping ERG to Resistance / Slope can work too. But it is an “external” step that requires app access. The bike shifting is more convenient and a simple use of a practice we already use outside.
You mention keeping a straight chain line in order to reduce wear, but that may cause disproportionate wear on a few cogs. Any thoughts on how to spread out wear across cogs?
The obvious answer to handle wear is it more evenly distribute the use of the chain across the cogs on the cassette by shifting with intent to use them all. As with anything in this space, there is a give and take to every choice. First, it takes concerted effort to think about your gearing and make changes at whatever interval you decide makes sense. Then there are the potential implications to flywheel energy and it’s impact on you and the training. This is all relatively new thinking and there are no concrete studies to what if any impact this… Read more »
Thanks, that makes sense. I agree it’s a lesser priority, and given all the other factors to keep track of, it’s probably better to ignore it for the sake of simplicity.
Get a cheap bike for Zwift sessions. Totally pointless wearing out your best bike on a trainer.
That is a fine solution for some, but not everyone has the space or funds for multiple bikes. There are a host of reasons people choose to train and ride what they do. It’s a mistake to assume that one solution is right for everyone.
When going from main effort to rest interval, I used to drop from big front to small front but this would drop wattage too much and my avatar would stop. Now I just keep it in big front and drop to 1 easier rear gear and let the trainer do the adjustment. Elite Real Turbo Muin.
Yeah, a big to small chainring drop, especially at the very start of an interval, without appropriate cadence change will lead to a huge power differential from the recovery side to the work side. You are forcing the trainer to make a large swing in it’s resistance unit. It will result in a big power delta until it catches up. With some trainers, that could be 5 seconds or more.
It’s best to accompany a large shift with a cadence change, if the goal is to keep the power roughly the same.
The Muin supports ERG in Zwift? I cancelled an order of one over a year ago and bought the Direto after more search. Confused!
I have a Tacx Neo 2 and I am struggling to find a great solution for 30″/30″ intervals. When keeping the cadende the same it takes 2 to 3 seconds (10% time loss!) to adjust. When I speed up my cadende (90 to 110) the trainer first tries to regulate the power down due to the cadence increase and the same happens when I change gear. The trainer tries to lower the power and after that it changes up. By this it takes 5 to 8 seconds until the power is at its target.. Any advice, except for using slope… Read more »
Depending on the app you are using, you may well be getting the “full effect” of the interval, even though you think you are missing. In general, if it takes something like 3 seconds to ramp up from the recovery wattage, to hit your work wattage, that comes from the inherent delay within the trainer. This matters since it seems that adjusting to wattage increase or decrease are identical (or nearly so) in their timing. Considering that, you will officially hit the target watts 3 seconds late, but there is a parallel 3 second delay at the end of the… Read more »
I’d always wondered this too..the lag on the trainer adjusting made me think I’m not getting the full workout , also..same…if I tried to ramp up ready for higher watts section..it actually made it slower to react. Best to spin same cadence and wait for trainer to ramp up for me
Yes, there are sometimes ways to “game” the delay, but usually the best option is to do exactly what you said, be steady and consistent with your cadence. “Cadence is king” is my motto for ERG work. Keep it as smooth and predictable as possible, and then let the trainer & app do the rest of the work.
I will shift in a ERG -based workout when I can’t seem to get the Power and Cadence demands of the workout step to work out. i.e. it complains about too high/low power or cadence. Otherwise, I tend to pick a lower gearing just to keep the noise down.
I sometime have to shift up in ERG mode as I start to drop cadence with tired legs. Heart rate showed not any changes. If I do not shift up I could see the cadence drop more until I get too much torque and stop.
Hi Chad, thank you for the article and the comments. Very interesting! I have a related question. On erg workouts, especially in the warm up stage, I typically are a bit above target watts while being on sort of comfortable cadence. The problem is that erg mode than slowly increases resistance causing my cadence to drop further. I would expect erg mode to lower resistance if I’m above target watts. When workout has watt and cadence target it works quite well even though I’m almost always a bit below cadence target and a bit above power target. Is this normal?… Read more »
Depending on the trainer you use, and the gearing you use in ERG, you may be hitting a wattage floor. Some trainers (like the Tacx Flux and Vortex) have trouble dropping resistance in ERG lower than some wattage, at some gearing.
So, if you have one of these trainers, it may require you to use lower gearing in ERG for these lower wattage values.
Been shifting since the CompuTrainer days of 1999 🙂