So I’m kinda confused about this. I have a Tacx Satori trainer. Which has a manual resistance lever. Now when I go uphill I change my resistance (So I try to simulate the route as good as I can). However, what with people who just keep their resistance on 1? Won’t that make it easier for them? As they don’t feel the hills like I do?
Doesn’t this make the game unfair?
Watts are watts whether you are on flat, incline or decline. I have the same trainer, but use a power meter with it and I don’t touch the resistance lever at all I just shift the gears. It is not easier or an advantage to do that.
Just so you know, I did use the resistance level a couple times early on and found that the trainer lost its calibration so I stopped doing it.
Im still kinda confused.
If I have my lever on lets say 6 and you have it on 1. Wouldnt it be harder for me to generate the same amount of watts as you?
Why would it, all you have to do is shift it into another gear.
It’s still that same watts.
If anything, it’s probably easier for you to apply force, since you have more resistance to push against.
Consider pushing someone’s hand. If they provide resistance, you can apply X force. If they move their hand away as you’re pushing it, it’s much harder to apply force. You’d have to push faster and further to generate the same total force.
Since power is a combination of (force * distance) / time, in other words you generate the same power, but the other guy has to pedal faster (increasing distance travelled by the pedals for a given time period) or use a higher gear (increasing force for a given cadence).
Something like that anyway. 
Consider an extreme situation where the other guy is on a trainer providing zero resistance at all. If in-game speed were purely dictated by wheel speed then yes he has it easier. But he can’t apply any power to the “road” because his wheel’s off the ground.
Thanks guys, that actually makes sense.
And makes me feel stupid…
Well this isn’t strictly true.
Watts are force x cadence.
200 watts at 50 cadence is very different from 200 watts at 120 cadence.
Now, on the flat, in the real world you can do 200 watts in a big choice of gears giving you a big choice of cadences and resistances. To suggest it doesn’t matter because watts are watts really isn’t true. Experiment and it’s easy to see that it does matter. Otherwise we’d just get a fixie and adjust our cadence to whatever wattage we wanted - watts are watts. Nope. It wouldn’t work.
On climbs, in the real world, you can’t pick from so many gears. If it’s steep enough you might end up in your lowest gear and at that point your only way of reducing the power is to lower the cadence and, equally, the only way of increasing the cadence is producing more power.
And then the 200 watts you twirled out on the flat leading up to the climb is going to feel a lot different to produce - more likely even grinding out a low cadence is going to be more power.
And that latter thing makes climbing very different from riding on the flat.
Especially given that bicycles seem to sold with mostly the same gearing. They don’t ask you what your FTP is or what the roads are like where you live. Most of us seem to get a compact. A few bikes are sold with bigger gearing. Not much that’s shaped like a road bike comes with lower gearing by default.
We kind of intuitively know it’s not the same. When a Sunday bun run posts the route for the week everyone is interested in how hilly it is. If watts were watts why would that matter? Why would they bother having races up mountains?
In zwift we have this ability to effectively compress the terrain so yeah, you can have the same force and resistance completely independent of the virtual terrain. But often the resulting climbing speed is so slow you’d probably fall off IRL and the downhill and cornering speeds are just ridiculously fast.
To some extent it makes it easier. Firstly, simply never having to change gear is easier, your power dips when you do this, and on 100% trainer difficulty if you’re having to change a gear at the front and a couple in the back that’s going to impact compared with someone who has just a bit of trainer difficulty so he feels the hill in his legs but doesn’t need to change gear. Secondly because, with a lower trainer resistance, you can spin the flywheel up and its momentum will be higher. On a higher resistance your trainer flywheel is going to drop speed faster and you feel that if you let up just as you’d feel it IRL if you eased off climbing compared with easing off on the flat and lastly because plenty of us will have too high gearing for the very extreme gradients and we end up IRL standing up and stomping up as best we can, whereas in zwift with trainer difficulty dialed down we can ride up a 15% incline in the big ring at 100 cadence. Which, even if the wattage is the same is most definitely not the same.