I have come across questions about this all over the forum and internet and am still none the wiser, completely different answers everywhere you look.
Am I right in saying all this does is change what gear you would use, for example if you are in gear 9 (whatever gear you want gear 9 to be) and doing 90 RPM and your speed is 20 mph and you turn trainer difficulty up and do 90 RPM in gear 9 you will be going faster than 20 MPH?
Not exactly, but close. Trainer difficulty does pretty much nothing on flat terrain - it sends the trainer a percentage of the gradient (uphill or downhill) based on the setting - so at a 50% trainer difficulty the trainer will think you’re on a 5% gradient when in Zwift you are on a 10% gradient - in that case it will feel like you’re in a lower gear. It will still take the same amount of average power to get up the slope, but you will be able to spin more on the climbs with a lower trainer difficulty rather than grind.
On the flats the trainer will see 0% gradient regardless of the trainer difficulty setting, so on the flats there should be no difference in your gearing.
This is Haziel, a Zwift Support Specialist, Let me confirm that the change in your difficulty won’t change how far or fast you ride, but it will change how climbs feel.
You’re absolutely correct that trainer difficulty impacts how much shifting you’ll need to do, especially since the incline changes may feel less dramatic. For example, with the default setting at 50%, your trainer treats the gradient as half of what it really is. So, when you encounter a 10% climb in Zwift, it feels more like a 5% climb due to the reduced resistance.
Lowering your trainer’s difficulty will decrease the resistance changes on those hills. It’s important to remember that the power you need to ascend the hill remains the same. You’ll still be putting out the same watts to cover the same distance, but the sensations will be different. I encourage you to check out the Zwift Insider article about trainer difficulties for more insights.
If you have more questions please contact us.
I think I get it, it changes your gearing on hills, when people say it changes a 10% incline to a 5% at 50% trainer difficulty it really does not change the incline it just changes your virtual gear so whatever real gear you are in feels easier, so it feels like a 5% but you could just put the trainer to 100% and drop into a lower gear and get the same resistance. Is that correct?
I think the article actually adds to the confusion, If at 100% trainer difficulty it takes 10 minutes at 200 watts at 80kg to get up a hill and you change difficulty level to 50% and it takes 10 minutes at 200 watts at 80kg then all trainer difficulty did was change your gearing, it may give the illusion of a lower incline but thats not what it did.
This is the best explanation of Zwift Trainer Difficulty I have seen (Reality Gearing or Virtual Cassette)
If you only think about how it works going up hill then OK, but going down hill it’s the opposite and on flat roads it does nothing. The video is misleading, though the point it’s correct about is the one that most people care about.
I would say for uphill it better explains how Zwift works, If I said in real life I can half the gradient of a hill by going into a lower gear you would give me a strange look, the downhill it says it does lower gradient but that would mean you need more power to go down it at the same speed and I don’t know if that is true or not!?
If you halve the gradient going up hill, you get less resistance from the trainer. If you halve the gradient going down hill, you get more resistance from the trainer. The hill feels less steep going up and down. If the gradient is 0% and you take half of that, you get 0% which is why it doesn’t affect the resistance you feel when you’re on level ground.
Zwift Halves the gradient with the trainer at 100% anyway on downhills so you don’t run out of gears, if you set it to 50% trainer difficulty then it will be down to 25% but am guessing this is not what its doing, am guessing its doing the exact same thing it does on the uphill but instead of lowering resistance it increases it, to go down the hill at 200 watts and 80kg you will hit the same speed at 100%(50%) trainer difficulty as you would at 50%(25%) trainer difficulty so its basically the same virtual gears, saying they reduce the gradient is not true, they are simply giving you a wider range of gears which gives the illusion or feel of a reduction in gradient.
Changing trainer difficulty doesn’t affect your speed at all. It will always be governed by Watts if all other things are equal. The question is whether you run out of gears going down hill with high trainer difficulty. If you don’t, great you can safely ride with higher trainer difficulty. But if your gears aren’t big enough and you spin out, then you won’t be able to match the Watts you could do if you had lower trainer difficulty, because you won’t have sufficient resistance. If you want to stick to that “gears” analogy, lower trainer difficulty means you get lower gears going up hill, higher gears going down hill, and no change in gears on flat roads.
You shouldn’t run out of gears going downhill with high trainer difficulty as its still only 50% at max, well not on a bike with a 50/11 gear, maybe someone on a 44 biggest chainring might run out.
“If you want to stick to that “gears” analogy, lower trainer difficulty means you get lower gears going up hill, higher gears going down hill, and no change in gears on flat roads.”
But this is exactly what is happening and best explains to anybody wanting to understand what the feature does, the gradient part is just confusing as its not whats happening.
You’re imagining a situation where the gears are not low enough on a climb, which is a common problem and lowering trainer difficulty helps. The rider probably can’t put out enough power to spin out down hill because they aren’t strong. But now imagine another common situation which is a rider with very low gearing. They have a mountain bike with a 32t chainring and a 1X drivetrain. They have a huge cassette. They are spinning out on flat ground and on descents. They show up on Facebook and ask how to make their gears bigger and they are told to raise trainer difficulty, which makes the problem worse on descents and does nothing on flat roads, because that setting isn’t about gearing, it’s about scaling gradients. This is why I think it’s more important for people to understand how the feature works and not reduce it to “lower trainer difficulty = lower gears”. It only means that if you only care about the climb.
I get your point but Zwift calling it Trainer difficulty does not help.
I have an answer to increasing your gears, if you are on bluetooth and change to Ant+ it will increase your gearing, theres an article online about it.
That’s why I end up explaining it on Facebook once a week at least. This is my hill to die on. Videos that explain it wrong don’t help either. The guy could have added 30 seconds of info that would have clarified the context in which it matters.