Hi all
As I understand trainer difficulty it’s About gearing. So if you ride with a 9 speed 11-28 you Can adjust The trainer difficulty so it feels like you ride with 11 or 12 speed, right!
But does anyone know at what percentage The slider in trainer difficulty Should be on to simulator 11 speed if you ride with 9 speed??
I have never heard it put that way but in my experience it helps you use the part of the your cassette that suits your style. I like to keep the front in the big ring and when I first started I was more in the lower gears (21, 23,25,28) in the rear . By setting my trainer difficulty to about 35% I can usually ride in 19,17,15,14. That leaves the 21,23 and lower for harder climbs and I still have the 11 and 12 for sprints. So you have a nine speed but can adjust the trainer difficulty to use more of the upper half or lower half depending on you style and type of courses you like.
Ah, Trainer Difficulty: The great debate of Zwift.
IMO, trainer difficulty is NOT about gearing, it is about gradient. That is, it doesn’t really affect the virtual gearing on your physical bike, it just affects how Zwift translates the virtual gradient into resistance on your trainer (presuming you’re using a smart trainer, that is). This, in turn, affects the actual gearing you are able to use to ‘climb’ or ‘descend’.
So, if you use the Zwift default of 50%, a 10% climb feels like a 5% climb, and you are able to use the gearing you would use for a 5% IRL climb. But it also changes a 10% descent into a 5% descent (or, really, a 2.5% decent, because Zwift is already halving the descent gradient internally), so you won’t coast as quickly going down. (This is why some people notice that they coast to a stop on a Zwift descent when on the same gradient IRL they would continue to coast down the hill.)
So, you can’t really use the trainer difficulty to change your bike from 9-speed to 11- or 12-speed, but you can use it to ‘flatten’ the terrain and make it seem like you have a wider range of virtual gearing.
(This is my take, at least. I’m guessing others will chime in with some alternate views.)
I had it set to 100% for a long time. I knocked it down to about 85% (I’m not currently looking at it… I think it’s just a slider without tick marks) and I feel like I have maybe 2 more low gears at my disposal ( (got tired of running out of gears on Alpe du Zwift). I would then expect to lose about two gears on downhill (chance of spinning out). I also think I do a little less shifting.
I interpret “trainer difficulty” to represent the challenge of finding the right gear at the right moment. The more shifting you have to do, the more difficult it is to be efficient. Ultimately, I’ll probably go back to 100% because I like having the full effect of my Kickr Climb (lower slider setting = less Kickr Climb movement). I also finally unlocked the Tron bike, so I spend a lot less time on AduZ where trainer difficulty was an issue (well, on the uphill anyway).
To reduce confusion, I think Trainer Difficulty should be renamed to:
“Trainer Realism” - because at 0% no gradient is simulated and at 100% it gives the most realistic simulation of riding your bike that your trainer is capable of.
“Gearing Realism” - because at 0% it simulates riding with a magic automatic gearbox with an infinite number of gears, so you never FEEL any gradients, whereas at 100% it simulates riding as if you have only the gears on the real bike you use.
The problem with gearing/gradient realism is that it’s limited by a person’s trainer - some trainers can only simulate gradients up to a certain level, so can only be “100% realistic” on shallower hills.
I think it should be Trainer Realism.
It won’t change how many gears you feel you have it;ll just change how easy or hard your gears feel going up hill.
so it might make you 28 cog feel like a 32 cog if you reduce the difficulty or make it feel more like a 25 if you increase it.
This is where decribing it using the term “gears” gets confusing, because you don’t “feel” you have extra gears if you dial it down, you just feel gradients less.
And it won’t make a 28 cog feel like a 32 cog - if you reduce the difficulty it’ll actually make a 28 cog feel like an amorphous cog which changes size gradually as you go up and downhill, effectively smoothing out the gradient you feel.
Thank you all
After Reading your answers, i see The training difficulty a little clearer.
So you could in your Own mind say i Got a few more gears, by sliding Down The difficulty a little bit, instead of thinking, i made The Hill easyer. You can see it in both ways?
Or i might not feel that I earned The masokist medal For going up The mountain 25 times, If i made The mountain easyer if it isnt About gears.
I slide it down to 40-50% just to use more cogs. I didn’t want to use the same 28 cog for everything from 8-20%. Now I can run 19 or 21 for 10% and not blow my hear rate out.
Also know that regardless of the trainer difficulty setting Zwift will still make you put the same number of watts. You’ll still suffer but in a different gear, 
The reason that I see the trainer difficulty setting as virtual gearing rather than “making the hill feel less steep” is that the latter isn’t the full story.
If a lower setting makes the hill feel less steep, then it also makes it feel longer. Because you need to put out the same number of total watts to climb the hill no matter your setting, whether that’s grinding up the hill at high power, or spinning up at a lower power output.
You’re kind of right Steve, and that’s one reason why “trainer realism” works better than talking about “gearing realism”.
At 0%, the gradient and distance of the hill will feel completely unrealistic, whereas at 100% both gradient and distance will be as realistic as your trainer can make them.
How about “hill modifier” or “elevation realism”… because it’s elevation based (both up and down) and gear choice is just the subsequent function. In my experience, 100% is most like in real life. 0% gives no feel for elevation (but still requires the watts). The lower the setting, the less connected I feel to the virtual road/experience.
Nothing wrong with using 0%, but I do contend a higher setting is in fact more difficult because of the need to change gears more often and at just the right moment for max efficiency.
I use full difficulty all the time… i have a NEO … but it is worth noting that not all trainers can simulate the hill grades in full … so it is worth knowing what your trainers MAX gradient is … as I run a TACX NEO 2 i know I get ALL the punishment i want… never felt a desire to make the hills easier … better just to take it and keep training on hills and overtime strength will come …
… there are no short cuts as strength comes with time … you still put out the watts by dropping the bar down to make hills feel easier but that is not my goal … with COVID lockdown Zwift and my trainer is the only exercise I can do as my road bike got stolen and bikes and inventory is hard to find which is frustrating when we actually do get a sunny day…
That is all good if you have big gears on the cassette and smaller chainrings.
Going up the Alpe in 48-26 is no fun
I used 100% for awhile with my H3. But I am big (103 kg), no VO2 to speak of and older. Once I hit >8% i started grinding the trainer. At 50% the trainer is much happier as it can turn more and is not trying to control at very low rpms…I think I was around 40 for the tower road and pushing 250 watts and it overheated. I can still do the grinding if I choose by going into a bigger gear but it affects the trainer much less.
… ah heck no … I’d suppose not … I have a 11-32 on my triple ‘trainer bike is old’ have not tried putting a 11-28 on it just yet
I think the reverse Innsbruck climb is the worst in the game - not for overall time but it is very steep for most of it.