There are 2 smart trainer modes used in the SYSTM app: ERG mode and Level mode. In Level mode, you will need to shift gears to meet the power targets, unlike ERG mode where the trainer meets the power targets for you.
Level mode applies a standard resistance curve to the trainer. The curve replicates outside riding- the faster you go, the greater the resistance. Outside, you get more wind resistance. If you’ve ever wondered why you are always riding in a headwind, this explains it. You’re just going that fast! So on a trainer, with a resistance curve, you will have a similar effect.
Each trainer will have different levels, each one will have a steeper curve, adding a greater amount of resistance with speed. There’s a great graph here of the power curves associated with the different levels for a Wahoo Kickr.
How can you figure out what the resistance curve is for your trainer? You can test it out! Choose a workout in the app that has no intervals such as Open 15. Set the trainer to Level mode and choose Level 0. Start in your easiest gear on your bike (small chain ring- largest cog) and pedal at a constant cadence of about 90. Then shift your gears one at a time, every 20 seconds until you have gone through all your gears. When you get to the last gear (assuming that you can), after 20 seconds, go all out to see what the trainer's peak power is at this level. When you've completed this, save the workout so you can view your workout file in your passport. This test will give you the range of power available for this level. Repeat this for any other levels you would like to test.
You'll notice the following: Increasing the level increases the size of the step between the gears. This will be more noticeable with a greater change between the levels. The stairs become steeper, just like the power curve in the graph up above.
You may find that the test is difficult to do for all the gears on your bike, but that it can be sufficiently useful to determine what gear you need to produce the power you need for Full Frontal or Half Monty. Levels 0-3 are usually sufficient for most users.
How do I choose the Right Level?
There are a few things that you should consider:
1- choose a level that allows you to reach all your power targets for your 4DP profile. Most people can find one level that will allow this, but it is ok if you're using different levels for different parts of the test.
2- choose a level that allows you to reach your power targets, plus a bit more or a bit less, at a comfortable cadence. Each step measured in the previous experiment was done (hopefully) at a cadence of 90. You can vary the power within the range of that gear by varying cadence. Slight variations in cadence are the best way to pace Full Frontal or Half Monty. Shifting gears will produce a large drop or increase in power and will make pacing more difficult.
Most likely, it will take you a couple of tries with Level mode to figure out which one works best for you. Stronger riders will tend to need the higher levels but many riders will find level 0 or 1 to be sufficient. Each trainer is different, so this is really just a starting point to finding the level that works best for you.
When should I use Level mode?
Level mode should be used when you’re trying to determine what you’re really capable of. You are the one in control of putting out the power! This is why Full Frontal should be done in Level Mode. The constrained effort in Half Monty needs to be done in Level mode also, as you adjust your power output based on your pre-determined heart rate constraints.
Every workout can be done in Level Mode if you choose! There are benefits to training in Level mode, just as there are benefits to using ERG mode. We recommend doing a few workouts in Level mode before attempting a fitness test so that you are familiar with how your trainer responds using this mode.
How do I select Level Mode on my trainer?
From the device connections screen in the workout player, select the settings under the trainer connection box: