“Trainer Difficulty” is absolutely the most misunderstood Zwift setting (Menu>Settings). Zwift’s help video says:
This adjustment won’t change how far or fast you ride, but it will change how climbs feel…
This setting is really a “gradient scale.” Zwift is constantly sending current gradient numbers to your smart trainer, and the trainer adjusts its resistance to match the gradient you are riding. The Trainer Difficulty setting scales the gradients sent to your trainer.
Trainer Difficulty is set to 50% by default, which is why Zwift says it “treats the gradient as half of the true grade.” So when you hit a 10% climb in Zwift, your trainer is only giving you the resistance of a 5% climb.
Bump your Trainer Difficulty up to 100% and you’ll feel the full gradient. Set it to 0% and you won’t feel gradient changes at all!
How Trainer Difficulty Affects Your Ride
Lowering your Trainer Difficulty decreases resistance changes on hills. You still have to put in the same amount of power to get up (and down) the hill, but you will “feel” the hill less.
Another way to look at it: Trainer Difficulty determines how much shifting you will need to do. Where you might typically use ~7 of your gears when riding at the default 50% setting, lowering it to 25% would let you ride and only use ~4 gears, since the incline changes are less dramatic.
Increasing your trainer difficulty, on the other hand, will force you to use more gears. So instead of 7, you may use 10 or 12, since the hills will feel steeper and you will need to shift more to maintain a healthy cadence.
What It Does Not Do
Changing Trainer Difficulty does not change the power needed to get up the hill. You still have to put out the same watts to move the same distance as before… you’ll just be doing it in a different gear.
“Trainer Difficulty” really is a misleading name for the setting. Perhaps “Gradient Feel” or “Trainer Realism” would be better.
Frequently Asked Questions
Doesn’t a higher Trainer Difficulty make racing harder? Am I “difficulty doping” by running it lower?
A higher Trainer Difficulty will typically result in a higher VI due to more resistance fluctuation. For many riders this may result in an overall effort which feels more difficult since maintaining steady power is easier than doing intervals.
But this isn’t true for everyone, and skilled shifting can reduce or eliminate the effect of resistance fluctuations.
In the end, watts are watts, and your Trainer Difficulty setting doesn’t change the power needed to cover any particular stretch of Zwift tarmac. So set it wherever you’d like!
I’m spinning out on descents. Can Trainer Difficulty help me here?
One common complaint from smart trainer owners is that they get dropped by other riders on downhills. Especially if you’re running Trainer Difficulty at 75% or more, steep gradients simply won’t offer the resistance needed to put power into the pedals. It’s the same outside!
The problem comes when you’re racing against others who have their Trainer Difficulty set low, or perhaps are riding dumb trainers with a constant resistance. These riders will have the resistance needed to go hard on the descents, while you’re spinning out.
Trainer Difficulty can help here. Try lowering it to 25-40% when racing. This will make hills seem less steep, and allow you to put more power into the downhills. Give it a try and tweak the setting until it feels good to you.
For more on this topic, read Trainer Difficulty On Descents: Did You Know? and Hanging with the Group Over Gradient Changes. Also–don’t forget the Supertuck!
I have a KICKR Climb, but it doesn’t respond to gradients because I’ve lowered my Trainer Difficulty. Is there a workaround?
There’s a pretty simple hack for this–see KICKR Climb Wheelsbase Hack for details.
Why don’t I see “Trainer Difficulty” in my settings?
The slider is only visible once you’ve paired a smart trainer as a “controllable trainer” in the pairing screen.
Should I Change My Trainer Difficulty Setting?
No need to change the setting if you are happy with the “feel” of your rides and aren’t struggling with yo-yoing in and out of the pack on group rides. If you think you’d like to adjust it, though, go ahead and give it a try–you can always set it back to 50%.
Thanks Eric for this article.
It helped clarify what this setting does. I was training at 50% (the default I think) and last spring, when I went outside to real hills, some of them kicked me pretty good. So I want to up the trainer feel of the hills for climbing so that when I go outside, there isn’t as big a difference.
Thanks – I am bumping up the setting to see if it helps with this.
Ride on!
I have the Kickr Core. Why don’t I feel the cobblestones, dirt, or wooden planks when I ride Zwift? Is there a setting I’m missing somewhere? I have already paired with bluetooth and the Controllable trainer.
The KICKR Core doesn’t have a road feel feature. That’s just the Tacx NEO trainer.
I don’t like the TD-setting at all, to me there shouldn’t be any other option than 100 %. What’s the point and sensation in going up the Alpe du Zwift without feeling its true gradient? When I started Zwifting about two years ago I didn’t have a clue about TD and it took me a while before I became aware of it. Now I always use 100 % because it’s so much more real, and fun, and anything else feels rubbish to me. Everybody is of course free to use which setting they like but I think there are a… Read more »
I always ride with setting at 100%. Personally I like the regular shifting. It turns what can be a rather monotonous task into one where you’re constantly having to pay attention to what’s happening (I use for general fitness over winter rather than training for races). With trainers in the past I’ve required music, etc., to overcome the boredom. I now usually ride 1.5 hours with nothing other than the zwift screen in front of me. The necessity to be on the ball keeps it interesting and the miles fly by.
This article really helps clarify what the slider is used for. Up until this point I thought that it was increasing or decreasing the resistance across the board. Does anyone know if this is available elsewhere? The issue I’m having is that my mountain bikes gearing is not great for riding many areas in Zwift. Even with the slider at 100% I find myself operating in the highest two gears 80% of the time. I believe that a way to increase overall resistance or a virtual shifting feature would help out a lot of riders who are not using road bikes.
I wish this feature existed in Zwift, but it does not! Depending on your trainer, there may be ways to hack it from the trainer’s side, via the app used to set it up. Might contact trainer support.
Hello.
I have been using Zwift for 2 days.
I use Elite turbo muin smart b+ indoor trainer.
I can’t see the trainer difficulty setting in the settings menu. Why is it?
I use Zwift on my computer(Windows10) and on my Ipad.
I am still using the trial version.
Thank you.
Make sure you have your trainer paired in the “Controllable Trainer” box on the pairing screen.
Unfortunately I can’t pair my trainer in the controllable trainer box. 😞
Thank you.
My trainer only transmits power.
Hello Eric, in the app of my iPad does not appear this function, why? Thank you
forget it now i see it sorry
Thanks for writing this up! I have a gravel bike SRAM 1×11, typically using the top 3-4 gears only, and can spin out on the descents. If I’m understanding this correctly, if I increase the TD setting to 100%, I will probably use more of my lower gears to climb. However I will probably still spin out on descents, unless my bike had higher gears. Does that sound correct?
Correct.
This may be a minor point, but does Zwift send gradients to the smart trainer, or does it send the required brake force (or maybe brake torque) based on all of grade, wind resistance and rolling resistance, the latter two being calculated by Zwift based upon the riders speed. Or maybe it sends both so the Kickr Climb can do it’s thing?
It sends gradient, rider+bike weight, wind resistance, and rolling resistance… maybe more?
It’s up to the trainer’s code to simulate the feel properly based on those parameters. (The parameters may vary a bit between Bluetooth and ANT+, because it’s two different protocols and specifications…)
That interesting (and surprising). Since all of those factors ultimately result in that single number (brake torque), it would allow for simpler design of trainers and for Zwift and its competitors to bring in sorts of different factors that they might imagine to make the experience more like IRL. For example, I think if Zwift could just transmit the brake torque it would be easy to implement draft feel.
Thanks for explaining how TD settings impact on the experience. One thing I’m finding out reading your post is that one has to shift through a climb… I’m confused as I thought that ERG mode was taking shifting out of the equation on rides. The times I’ve tried shifting gears made a slight difference for a few seconds, but after that, no notable difference from cycling in the previous gear.
You don’t need to shift in ERG mode. You DO need to shift in SIM mode (which is what is used outside of workouts on Zwift).
thanks eric, didn’t know this! does Zwift shift you automatically to SIM mode on regular rides?
Yes. SIM mode is basically what’s used as default. ERG is only for workouts.
My mph seems way off. I am new to Zwifting, however, not new to riding and I know what speed I am capable of riding. I tried the calibration method and it still is not close. Any suggestions? Thanks
Contact Zwift support, or your trainer support. It’s all based on the wattage your trainer/power meter is sending out. [email protected]
Is there an easier way of going into the menu, instead of starting your ride first then pausing to bring the menu button.
No need to pause. Just click the mouse or tap the screen to bring up the menu button. You can keep pedaling while in the menu…
You must be kidding. I thought everyone rode with trainer difficulty at 100% or you were cheating or certainly not preparing for the climb outside of equal difficulty. Really some riders go at 50%?? I missed that note. Got it now.
Default is 50%. I would guess the vast majority of people run it at that!
Zwift why don’t they sell a turbo trainer that sends a code to set the resistance when you click the button to start a race. Every one would be riding to the same resistance setting that would be a game changer😀
Hello! I use zwift since 2 years. I always let the setup at 50%. My ftp is 270. I go quite strong on flat TT, performing exactly what is expected with such http://ftp... But in Alpe du zwift, I cannot go beyond 220/230w continuous or I totally overheat. I thought it was because of lower pedalling speed, or anything else. But yesterday I touched the setup, put it at approx 25%. And surprisingly, today I was way faster, climbing over 250w. The feeling in climbs is much easier at previous speed, the difference is huge. This is not supposed to… Read more »
Eric, do you know if TD could be changed during a race and if so, is it allowed? As this would /could have major consequences.
Yes, you can change it on the fly. No rules preventing it that I know of. Wouldn’t have any consequences other than how it affects you!
Thank you Eric,
That is very good to know, but you say it has no consequences?
What about recovery after a steap climb @ say 5% followed by a descend @ 100%?
IMHO it has major consequences that way
Not sure what point you’re making, Rob. I said the only consequence is how it affects you – meaning there is no consequence outside of that, like being DQ’d from a race.
There is one important piece to this that needs to be made clear. At some point, when the gradient becomes very steep you will have an insufficiently low gear to enable peddling at comfortable cadence. The gradient this happens at changes depending on trainer difficulty. Ie you may find that going up Alpe du Zwift with difficulty set to 50% is possible in your lowest gear at a reasonable 70rpm. However, set this to 100% and you cadence may drop into the 40’s! which is hard and very like real life. While it is true that pushing the same watts… Read more »