I'm with Chris here. I always run my trainer difficulty on 100% as I think a hill on Zwift should be the same as a hill outside. You don't get any rider preference on hills outside!

Chris is right in that it is more difficult to climb with the trainer at 100% but not for the reason he states, i.e. cadence being lower, because that could be fixed by changing gear like the other dude says. What makes it more difficult is that at a higher resistance, the pedal stroke requires more stabilizer muscles to be involved since you're not getting the inertia of the flywheel to "help" you out. So at a high resistance you're pedaling squares, which makes it harder. You can verify this by loading up trainer road, setting it to ERG mode, and doing a hard interval in the 53/11 and one in 39/25. The 53/11 will be easier due to the flywheel inertia.

I see the trainer difficulty as a "how much is this like the real world" setting. The term 'difficulty' is the wrong term for this setting as it causes the confusion that Chris is stuck on. If I don't care about the real world, I'll do an ERG workout, but having the %difficulty at 0% does nothing to help me IRL. I'm making the effort to make the zwift race as close to the real world as I can by setting it at 100% to adapt my body to changing gradients (knowing of course that it isn't exact). Others can decide to set it at zero, but when it comes to racing/riding in the real world, I feel I gain the advantage of knowing when to change gears, prep for a hill, and maintain my cadence, rather than just push watts in a set position.

i run 100% as i want to feel the outdoors as much as possible but for fairness i think when you enter the pen ALL racers should get either 0/50/100% depending on the race

Honestly I get Chris's point but he's making his argument on how realistic something is, we are talking here about a game with power ups and driving above lava lakes..

Totally agree that in a race everyone should have to feel the terrain in exactly the same way and should have to use their gears in the same way.

I watched this video and decided to do my own experiment. My last 3 times up epic kom were with 3 seconds of each other. 30:12, 30:15, and 30:08. I wear a Whoop band and do my best rides when my recovery is really high and it says I'm ready for "peak" performance. Today indicated a great recovery and rested body. I rode today feeling good and set my trainer to 0% . I've had it at 100% for the life of it. Race st 100% noodle at 100%. I shaved a full minute of that climb29:23! It's really difficult for me to keep my watts up on any downhill section but with the trainer set at minimum it really easy to find a rythm and put your head down. I also have thr kicker climb for added realism. I can literally close my eyes and ride with a perfectly level heartrate no spikes, no bumps in the road. This is completely unfair for racing. I agree with Chris 100%. Races should have a mandatory setting that we all follow. Climbers will get beat by time trialists and so on. Why would anyone pick a hilly climb and set the trainer to minimum? Not fair at all in zwift racing. It's like setting a metronome and riding to it. Not the point of riding at all. Great for guys and gals who ride flat roads all day and want to keep training for that. Hills are supposed to be more difficult. Pfft...

I just think of the difficulty setting as a way of "virtually" modifying your cassette.

Trainer Difficulty is simple. I run a 12-25 cassette. With a 25 tooth I will run out of gears to be able to climb at a sensible cadence on climbs like Radio Tower. Lowering the setting to 25-30% is like I changed cassettes to a 12-30 tooth. I still have to produce X watts to go at a certain speed, but now I can pedal at 80 rpm versus leg pressing a 25 tooth at 40-50 rpm up a steep climb.

Trainer difficulty setting certainly makes a difference in Zwift. Yes a given watt registered by Zwift is treated the same regardless of the trainer setting but how you produce that watt has a different impact on your body. Case in point if I set my trainer difficulty to 0, then I don't have to worry about gear adjustments to maintain my ideal power to cadence ratio. I can just spin away at a set cadence/gear producing watts. With the trainer difficulty set to 100 I am going to have to be playing with my gear selection to try and narrow in on my ideal cadence/gear ratio. Depending on the grade resistance I may not be able to hit that ideal ratio as closely as when the trainer was set to 0. Also every time there is a grade change, your body is being hit with a different stress load until you can find that ratio. Those stress loads add up over time. To add to the complexity, every trainer will feel different at a given set difficulty setting so just saying, everyone should set their trainer to 100 doesn't make things a level playing field across all riders. My advice, just ride at a setting which you find most enjoyable...

Try going up a 15% hill in your TT position at threshold.

Why don't you change your gears Chris, for the love of god?

I don't think very many people ride outside with a 32/32 gear, that's basically what a low trainer difficulty does. If you run out of gears then you have to grind and that is 'harder' because it's not as effecient.

Change gear Chris! What?... What did you say?... Run out of gears you say? Well put some granny gears on your bike for climbing or if you are on zwift just tweak the trainer difficulty! The main disadvantage is not the resistance or cadence uphill, it's the change of incline which requires more gear changes for those on 100%. By the time you find the right gear you sometimes have to put an effort in to get back on the group.

If 100% is the same as 0% then why does everyone buy bikes with 11 speed and now 12 speed cassettes to keep the gaps small? It's easier to sit in one gear at your ideal cadence. The biggest difference is when cresting a hill, those on 0% just shoot off as those on 100% are producing half the watts before shifting into the big ring. The one problem is, not everyone has a smart trainer, so there needs to be a 0% option

Chris is definitely right here, while the energy/effort expended is the same, the way the muscles are used is different. The comments about gears actually support his argument: if there was 'no difference' then why do we use different gears to spin up climbs in the first place? Essentially what the trainer difficulty is doing is giving you an unlimited gear range, which is surely an advantage?

While you are correct that a watt is a watt, there is a difference in how it is produced that places more/different stress on the body. This leads to the effort being percieved as more difficult at a higher trainer difficulty: 1. Having to shift gears - this leads to irregularity in power and causes spikes above and below target power, which causes more fatique. Just like workouts where you do Over/Under FTP efforts are harder than keeping power steady at FTP even though the average power is the same. 2. Inertia - Keeping up the same watts, but in a lower gear (which is required for climbing at 100%) means that the trainer's flywheel has a lower rotation speed, thus having less inertia. As a result the way you have to exert force on the pedal changes. The lower inertia of the flywheel means you have to exert force on the pedals over a larger part of the pedal rotation. This may feel unnatural, causing more fatique. In my opinion this is something that should be used in training ERG mode too to get optimal training benefits. Alternating between keeping a certain wattage at a high gear vs a low gear. The lower inertia will better simulate climbing in the real world whilst higher gears will better simulate a TT on the flat.

For official races, there definitely needs to be a standard and I think for your KOM it should be at 100% as well. I prefer to climb at 100% difficulty. I have had certain workouts that I keep the same cadence but don't feel like I accomplished the KOM like free riding at 100% difficulty

The difference has to do with fly wheel rpm. Muscle recruitment is slightly different at high speed/flywheel rpm( big gear) than it is at a low speed/flywheel rpm(small gear). Both are difficult in their own way and require specific training to develop. This is one reason why pros motor pace. Try doing two intervals in erg mode at the same power and cadence but do the first one in the biggest gear and the second in the smallest gear = Two different workouts. Those that do flat TT style riding/training will have an easier time with no resistance while climber style riders will have an easier time with 100% resistance. Someone at 0% resistence is riding a different course than someone at 100%.

what gives a better experience? steady resistance, or changing gears?

You guys need to look at it from a total energy perspective and not a power perspective. Power is with respect to time. Energy is the power multiplied by the amount of time. So, will a person putting out 300 W on a hill go the same distance as someone putting out 300 on a flat? No. Remember: a calorie is a calorie (joule is a joule), a watt is a watt...but the total amount of energy needed to travel the same distance on a hill vs a flat is different. This is due to potential energy (E_p = mgh) gained while going up a hill. (source: I am an engineer) P.S. Khan Academy has some great entry-level physics courses :D

I think another difference is the decent, that's where the 100 % setting shines 😆

I agree Chris, I'm a beginner with max settings and old bike (with 11/25 gear) and almost got destroyed by my first climbs because I ran out of gears and started losing cadence. That would also happen in real life and that's why I keep it like this. I might upgrade the cassette though to for climbs in both real and virtual biking.

I totally agree with you. First day I got on Zwift I set it to 100% and haven't changed it. Don't know why I would.

I totally get what your saying (maybe). Ive done 1 race on 50 % resistance. "Magically" I managed to set a new FTP ive never been close to copy with 100 % resistance. And it wasnt even close. Ive never managed to get closer then 21 watts which is a pretty substansial gain just for changing the resistance. I get what people are saying that watts are watts, but .....

Great video again, I was wondering the exact same question but I couldn’t be bothered to test it

Have definitely been through the range of thoughts Chris does here while trying to settle this in my own mind!

Thanks for addressing this but although the wattage output are the same surely it comes down to the level of fatigue and power produced through that effort and how long your muscles can deal with the resistance change...

Chris, here is what I would like to know. what gives the fast lap on the Fig8? A consistent power all lap (e.g.100%time @200W) or lower power on flats (e.g. 90%time @170 and higher power on climbs (e.g. 10%time @270), but average again @200w?

Yeah but when they have zero difficulty set then when we are recovering on the decent they have to keep peddling. I think the best argument is why did we spend $1000 on a smart trainer to turn it into a dumb trainer.

just a question, will the trainer axle turn at same rpm in each position of difficulty at same watts in same moment?

Looking to do an easy IRL this weekend , setting will be at 0% to make the climbs easier on my muscles

Chris you are 90% right everyone should have the resistance set at 100%. Having climbed the Alpe in Zwift more than 100 times , I have the Trainer Difficulty set to 100%. I like to feel the gradient with the Kickr Climb as I would outside but I use the gears on the bike also as I would outside. I love to Climb the Alpe on Zwift out the saddle also I usually ride on the big ring at the front and use 2 or 3 gears on the back , my cadence is really low but it feels to me as I'm riding outside in the real world. Keep the videos coming Chris really appreciate your comments and topics on Zwift.😂🐐🚲💨

Even the smoothest gear changes lose power on an undulating course. You gain an unfair advantage in a race by cutting out the gear changes.

Some how I completely understand where you are coming from and agree. 😂

Hey Chris! Just wanted to say many thanks for your efforts. Brilliant content and funny as.....

Chris is doing the Fred Whitton on a fixed gear bike so he "can really feel it". :)

On the Bologna TT there is a 20% grade, if someone can have a steady cadence then it will be a lot easier.

Hi I'm new to zwift and after watching your UKposts on this subjectthe I done the 14km Yorkshire ride in 31,47 sec at 100% to day 30,50 sec at 50% I'm not young or fit,Great videos.

How do we make sure that in the time trials that everyone is always in the TT position and not sitting up? We can't produce the same amount of power in a TT position

Agree with Chris, however did he use all the gears or just stay in the same gear each time..

I agree 100% with you !! Just ride at 100% for racing. The fatigue is different ... for the grinding. In the real world you don't get to go 50% in racing....it comes down to fatigue level at the end regardless of gears

So I cant change my gear sets (Atom ) so would be disadvantaged ?

Everest up Alpe du zwift on all 3 difficulty setting 0% 50% & 100%. which one will hurt the most?

The difficulty setting is effectively changing your gearing ratio. Pros have different setups for climbing that allow them to spin up a 7% gradient. Lower the slider to give yourself the same effect. If 100% doesn't allow you to spin up the gradient your on, lower the difficulty until you get your desired cadence.

Wattage is what moves the avatar so even if the slider is set low, unless you generate wattage, the avatar isn’t going any faster. A lower difficulty only means you have to spin that much faster. It’s basically to help the gearing of your bike. If your bike is set up with tall gears, slide the difficulty down so you can make those climbs. If you have a compact crankset and large cassette, set the difficulty higher so you don’t spin out on the downhills.

On my Neo 2T, I do find that 300W in a deep gear w/MAX trainer difficulty, uses different leg muscles than 300W in a higher gear (at the same cadence) I would describe it as a flywheel effect. Low gear = low flywheel effect and a drag across the entire cadence rotation High gear = huge flywheel effect, and very little drag across the cadence rotation. More of the effort comes from stomping as opposed to carying the pedal around. Analogy: (No trainer difficulty) glue a scale to a low ceiling. See how big of a nunber you can get pushing up against that scale. (lbs are lbs) Analogy: (MAX difficulty) replace scale with a weight equal to your best effort. Now you have to deal with swinging that weight into the optimal position to execute your effort, can you even get it into position? (lbs are lbs) In Summary, I do feel no trainer difficulty gives you an advantage. No messing with gears, no akward power delivery. That said, I still use MAX. Its more enjoyable, realistic and better conditioning.

Chris is 100% correct. What he’s not making clear enough in his argument is that on a steep enough gradient in real life, you will eventually run out of easy gears that would allow for you to have the option of efficiently pedaling at 85-90 rpm. On a big enough hill everyone is eventually grinding. If your trainer difficulty is set to zero, you’ll never notice a difference going up the hill, and yes, while the wattage required to get from point a to point b IS the same, the way in which you produce those watts would be at a very easy breezy 85-90 rpm. With difficulty set to 100 on a steep enough climb you will eventually run out of gears (much like you would in real life) forcing you to grind up at a lower cadence. The lower the cadence, the more torque required to produce the same amount of wattage. It’s more physically demanding to torque (grind) through at a lower cadence. Trainer difficulty at 100 will require you to grind in certain scenarios, because you will eventually run out of gears. Now, if you’re on a mountain bike, that’s a whole other can of worms.

To make it the same for everyone you would have to enter you gear ratio on your real bike and then have zwift modify trainer difficulty to effectively give everyone the same range of gears in game. The problem with setting everyone up with 100% is that to do a race up Alpe d zwift is those people in the real world who have a bike geared for large mountain would have an advantage. By letting people adjust there own difficulty we get rid of that real world advantage and instead make allow people to have a virtual gear set they like.

So, as long as you have gears left to shift up/down and maintain your preferred cadence, there's no difference... right?

The bigger issue is does 300W on a Neo equal 300W on a Kickr etc at all trainer flywheel/virtual flywheel RPM's?

I’ve gone up the radio tower when tired in a group on 100% and ground to a halt in my easiest gears. I changed the trainer to 50% then proceeded to catch up and overtake the group in front before the top. In my mind that makes the 50% setting easier to ride than the 100%.

Chris is completely right here. When you run out of gears then you can’t choose cadence and it gets a lot tougher. Also, the gradient changes need you to always be on top of selection which means you can’t just stick to an absolute cadence and power.

Chris you right, don't let them get you down. Chainging gear make the effort harder, and sure if you are in a road bike 36 in front 28 in back you you strugle to get good cadence in plus 10% gradients.

anyone sync with wahoo app prior to getting into zwift to do standard mode power? feels less erratic, can control resistance from there.

Some people has direct mount trainers. Thus when you put it on 100% the wheel just start slipping when the gradient change. That's why I keep it on 50%

Perhaps it should be auto set to 100% for any group activity but you can set it yourself if cycling alone?

1st comment- Just a thought- Is 0% resistance = compact crank. 50% = mid-compact and 100% = regular crank? 2nd comment- I've also wondered if I have it at 100% going uphill would that allow me to descend in a bigger gear (like real world) vs 0% resistance using almost the same gear I climbed in?

Which setting actually matches the gradient? If I want to train for Alpe d' Huez, which setting will render it on Alpe du Zwift most authentically?

Trainer Difficulty is great for those like me coming back from injury and totally unfit. I have it at 50% so I can get some effort but not blow myself to pieces on the 10-15% sections and be unable to finish the ride. As I get fitter, I can increase the difficulty. I tend to agree with Chris about having the Trainer Difficulty at 100% in a race IF WE WANT TO MIMIC OUTDOORS.

You are right Chris, like every calories are not the same, every watts are not the same lol The other guy is being to simple with a "watt is a watt", it's all about the impact on the body.

Totally agree in a race it should be 100%,,, i find it much easier doing 300 watts on the flat,,its not about what gearing its because of the resistance on the climb is forcing you to keep pressure all the way through the pedal stroke ,,,,the only people that will say it don't matter is the ones not riding at 100%,,

The only limiting factor is the size of the cassette you are prepared to fit. I could spin my way up any Alp or Pyrenean climb as long as I fitted a large enough rear cassette. If Zwift didn't have this have this feature, it would exclude people with smaller cassettes from fully enjoying all the courses in the game, which is I assume, why they did it. Decreasing trainer difficulty simply mimics fitting larger cassette, something we all do these days, compared to the cyclists of the 60's,70's etc.

Chris, maybe this will help you understand the difference between 0% and 100% on your trainer. It is not an unfair advantage because if you move the resistance level down to zero it gets easier on the climb but your speed goes down as well. It would be the equivalent of someone changing the cog on their bike for a climb from a 11-28 and a 53 big ring to a 11-34 and a 50 big ring that day. Keep up the good work. Love the videos.

Difficulty mean using the gears more. End of! 300w is 300w at 0 or 100% 1 you can spin the other you can grind as proven in the video. Here is where Chris should be truly triggered. The difficulty also affects downhill. 🤪🤪 And what if someone has a turbo that can only resist 400w/500w and 5% power accuracy vs the kickrs 2000w 1% accuracy???

I agree that we should all feel the same terrain, but here's the rub; I have a Tacx Flow, which only allows for a 6% gradient. I assume that after i max my 6%, I take a speed hit to compensate the lack of extra resistance. So how do we reconcile that issue. Must we all lay out $800+ for a trainer to swim in the same pool? Should their be separate divisions? We could call them the haves(or sponsored) and the Have Nots divisions. In my mind, there is no question that navigating the terrain by changing the gears, picking you gear set, and timing the gear changes (etc.), are part of the race, and not having to do this is a distinct advantage, and should not be allowed. However, if you want to train on 0%, who am I to argue. But races should for sure be on equal settings.

I ride at 50 percent . When i ride Central Park on Zwift my speed up that climb is consistent with when I actually ride at the park in real life . So the setting does not change the power our the steepness . If i ride my old crit bike with a straight block 12 - 21 cog set i can get up that climb if i set it to zero as though i had an 11 to 32. The wattage does not change only the cadence which can be achieved through gearing .

Let's compromise and all have it set to 50%, it is the default afterall!!

I did Alpe dH on zwift at 100 and next day at zero. I can say stats were similar but the effort at zero was tolerable vs at 100 I felt like I ran out of gears. For me zwift races should lock to 100 and all other times you do what you want.... Or another option is no result on zwift power for races where resistance is less than 100. Today I try the third experiment which is back to 100 and see where I end up again. Love the video and channel gents.

Happy New Year Everyone!! Be happy and healthy! :) When I ride in a real world I can prepare myself for a climb, I can speed up, and when the incline starts, I change gears and simply ride on. Same thing when zwifting at 50% set. And it feels pretty REAL. Yes, I lose speed, but I keep on going quite easily. If you set it to 100% it feels like when the incline starts - you hit the wall, and you have to put too much effort to just keep going. Never felt like this on a real road. 50% is set by default, and I think it's done for a reason. If you want more, wanna suffer - this option is available! :) So it's all up to you :) But I do agree that when racing - everyone should be on the same settings!

My Neo has been at 50% since I got it in February. I've been toying with the idea of turning it up to 100, but I already climb 1000 m a day and don't know if I hate myself enough. Maybe after I have earned the Tron bike. Only 13,000 m left!

Trainer difficulty 100% matters especially up climbs. Having to adjust your gears on a all out effort definitely drains energy

I’m also in the 100% club. Within a mile of my front door there’s a hill with 17% gradient and I have to ride that with whatever is in my cassette. While I might benefit from turning my trainer down to 80% allowing me to increase my cadence, out in the real world I’m going to be grinding up that big hill so I might as well get used to it. To my way of thinking I guess it depends what you’re training for as to whether you go for 100% or not.

Stupid test, he should be allowed to change gears in 0/50/100 to show if there is an advantage big enough in zero compared to 100 with the gear range in a typical road bike

That was painful to watch! So yes a watt is indeed a watt, however I’m confused as to how the other guy doesn’t seem to get Chris’ point 🤦🏼‍♂️ Fair enough Zwift is not the real world so different rules apply, however 350 watts up ‘The Burway’ (Steep climb in Church Stretton, UK) would be extremely difficult to do in the tt position. If however it was possible and you could turn the real world difficulty down to zero it wouldn’t be fair compared to climbing it in reality as you would be going up in a more efficient position for the body. Where as real life climbing out of the saddle (even producing the same watts) would be far more taxing on a rider especially at those gradients! Let’s keep hills as hills guys! 👍🏻

ok got it at the end lol. the reason why the trainer gets harder in the same gear is so we develop spin , the higher cadence means less watts to maintain same speed as other putting out same power . you need to develop spin

The difficult level is not an issue is someone do a casual ride or do their own training but where I would like it to be the same for everyone is when you doing a race. Then the climb must be simulated the same for everyone taking past in the race. Is this the case in a zwift race situation?

300W is 300W. You don't have to grind harder at 100%, shift down. Less than 100% is like having slightly automatic gearing. If you want everyone to use 100% to make things "even", you also need to force them to have the same gear ratios available. If you shift to keep the same cadence at 300W, you are doing the same thing that 0% does.

Chris, it's just like changing your cassette. It's a bit like in a bike race on the road not everyone has the same cassette. It's so people can make it easier or harder according to their ability without having to go out and buy a new cassette for the trainer.

I just ran some calculations based on P=(torque)x(crank arm length)x(Force)x[sin(theta)]x(rpm); solving for Force with Power constant at 300W with 170mm crank arms, and assuming all power is applied at 90° to the crank arm, I varied cadence by 10 rpm from 40 up to 90. As cadence went up the Force required to achieve 300W was lower, also of note the separation in required force decreased with each increase in cadence. Power is power, more force requires significantly more strength, and a point is reached where the force is either unacheivable for an individual or unsustainable relative to endurance. Cadence is king for the same power. This is where bike selection, gearing, components, come into play. It also lends itself to N+1 bikes and a bike for each unique type of riding. I'm leaning toward the 100% camp, and I would encourage which ever camp you choose, select your cassette according to what you want to do with cadence in mind. Some cadences can be unsustainable if resistance is insufficient, or it could just be beyond the capability of a single rider.

Watts are watts , we all have different gear ratios . Should we all do Alp du Zwift on a single speed bike ?

Chris a better test for me would be would be what is the time difference, going flat out with different trainer difficulties.

Same cadence and same power is not necessarily the same feeling or difficulty. On a flat you only need to apply power through a small band around the 3 o’clock pedal position (where the stroke is most efficient), momentum caries you through the rest of the stroke. On a hill you are slowed down much sooner and have to apply power much earlier. On the trainer it is the speed of the flywheel that simulates this effect. And setting a low difficulty allows you to quickly spin the flywheel on every incline making it feel like a flat everywhere.

I’m with Chris. People may have different gears in a real road race, but we’re talking about small changes in gear ratios & max number of teeth in the rear cogs. I get the whole “it’s flattening out the gear ratio” argument to allow someone to make a 25t cassette with a 39t crank feel like a 32t cassette with a 36t crank, but then that difficulty should be set in like the 80%-100% range for that smoothing… not 50% down to 0%.

I think with same cadence and power there shouldn't be a huge difference in the way it feels (100% setting may feel a bit harder but not that much). However I wonder what happens at +13% gradient with trainers only capable of simulating up to 10% gradient or even less? By default zwift is on 50%difficulty and that's what I am riding. Still feel the difference between 0 and 1% gradient as well as 15 and 16% gradient. Anyways spring is here and till October I'll be riding outside mostly, with that 100%difficulty in real world ;-)

I agree with Chris. I’ve been banging on about this for a year. Won’t Zwift power pick out the dumb trainers though?

At 100% my ‘wheel on’ trainer slips ( my tire slips) when I’m out of the saddle, which my road bike won’t do on the road unless I’m on gravel. maybe when I upgrade to direct drive, but for now I have to stick to 50%

If, when you change the setting to “max”, and you are forced to change your gears to a lower gear, that results in changes to your cadence and changes to your power output, which reduces your speed and increases your time to complete the climb. It’s a question of efficiency. Some riders can produce 315 watts and complete the climb efficiently on the “off” setting. The same rider may not be able to produce the 400+ peak watts necessary to complete the climb on the 100% setting (in the same time). So, all things being equal, the higher setting benefits the stronger rider. The max setting required greater work to achieve the same result - inefficient. Right?

I agree, 100% trainer difficulty makes for the most realistic feel... on longer, steadier climbs. However, when you're going fast on rolling sections like titans grove or pretty much anywhere in NYC, then sometimes the massive swings in resistance from -5 to +8 happen quicker than most turbos can keep up with; case in point you can be barrelling along a slight decent and hit a 10% climb with your flywheel spinning at 70 kph, then hit a steep climb, if you only lift off slightly not only does it "fake" your power because as the resistance kicks into a fast flywheel (i've been given power readings of +700 watts when i'm glass cranking) and then you might reach the peak of a short climb and be actually going down again and the resistance it still high. So in these instances the slightly softer setting of 50% can just make your ride smoother with fewer gear changes. So for general riding, it's just a lot less clicking through the gears. Where it's an "advantage" in races is where you turn it right down so that you barely change gear, keeping that smooth rhythm and on descents with trainer difficulty set low you can actually ride faster, dropping people on descents! I think for racing Zwift should automatically set all trainers to the same difficulty e.g. 75%. Thoughts?

The slider is there for different size cassettes period. Btw if it allows people to just get on the bike and get moving thats a win.

Interesting argument. One good point: if you are precise with grandient and resistance (100% simulation), at some point if you hit a 20% hill, you would MAY run out of gear at and drop under 60 rpm, but not by choice! Then watts have to be higher, otherwise it does not climb anymore, while rpm goes down! That's why some needs a 28 or 32 cog ... while your friend (0% simulation) is cruising maybe the same watts but spinning at 85 rpm not being obligated to push harder to climb. Is that right? I cannot imagine there was an argument! The holly triangle: Watts-cog-rpm! Gears "flattens" the hill... until you run out of it!!!!

Would be interesting to see if he set the gearing so that the perceived level of effort was the same - and see if the time up the climb is the same.

I agree w/ Chris. If I'm going up the same 'virtual' hill at 100% difficulty vs someone at 0% difficulty, they will expend less energy to make it up the hill. In a race, that 0% person will have more gas in the tank than I do. Its like a 8,000 lb truck going up a hill vs. a 2000 lb truck. That truck will use more fuel to get up the hill at the same rate as that 2000 pound car. More resistance depletes energy faster. Even if he changed gears he's still using more energy because he can feel the resistance more.

Chris makes a valid point if we all agree that we want to simulate real world conditions and environment. If you don't care than be at zero all you want. But for those who use zwift as a supplement to their outdoor training/progression, at least put it at 50% if not 100%

There should be a standard, but it should be variable to some degree, maybe making it so that the lowest you can go is 70 or 80 percent. The zwift hub direct drive trainer comes with a 28 tooth cassette, however, some riders like me prefer using a 34 tooth cassette. I keep my trainer difficulty at 80 percent, which basically simulates me riding with a 34 tooth cog in my lowest gear. All in all, it should be used as a tool for people like me and not abused for people to have easier races.

I agree that in a competitive setting, riders should be at the same resistance. But I expected that this was going to be a video about whether the same rider is achieving higher wattages at a higher or lower resistance. Personally I train at no resistance, because if I'm riding inside I'm just trying to get miles in, sometimes I'll use ERG mode but that's about it. I found that resistance does help me on races if my legs can handle it, but mostly because of my riding style--if the hill is short enough I'll keep a somewhat high gear for the hill and push through.

The thing start to get interesting when you climb Alp du Zwift and you get out of gears... you have to push 3.0 w/kg in order to keep climbing... with less trainer difficulty you are able to pace yourself better...

Chris I agree with the resistance across the whole race board people ride with low resistance and you over here with 50% trying your hardest to hang on

The way I see it..... its all about gear changes. If your gearing on the trainer is a bit clumsy then it’s handy to reduce the difficulty therefore less gear changes is required.

What about with a classic trainer...?