Very insightful Phil. I am all on 100% all the time in Zwift. In Dutch they call it 'stoempen', just power through it. But Eds option: change gearing for each stage on Zwift is also very viable. Again: great video!

Absolutely superb film. Accurate comparison and sound conclusion. I’ve always sort of treated a lower difficulty setting akin to having a really wide range cassette on my outdoor bike, which I suppose is what your experiment supports.

Lovely bikes great vid and thanks for zwift ride ons👍

Thanks Phill, always interesting to see different opinions and findings around TD 👌🏻 Personally I have mine set around 85%, this based on my effort grinding up Alpe d'Huez with the wrong cassette and approximately matching a similar experience for Alpe du Zwift :)

Great explanation 👌

I have just recently (2months ago) put my TD up to 100%. I have noticed a wonderful increase in overall strength and fitness on the bike. Indoors and outdoors. Here in the winter in Canada I do fatbiking on trails which requires higher cadence and good power output to get up hills and through the snow. I have noticed the improvement here, it is fantastic! Great video as always. Take good care.

Great video and a subject which certainly splits opinion. I always run on 100% as I want the experience to be as realistic as it can be, taking into account all the other factors and I would only be fooling myself. The ‘watts are watts’ brigade will argue it makes no difference and if so, why not just run at 100% then? 😊

10.48 perfectly sums it up

I personally love the feel of the TD at 100%. But again I love riding climbs too so I want Zwift to feel as close to acending a hill/mountain as possible. I did do a trail a few moons ago with different levels on different days and I certainly found I was more fatigued after doing the same route at 100% rather than 50% & 75% even though the average watts where roughly the same.

Nice test Phil. I ride Zwift at 100% and have my weight set spot on my 13 stones. I think if you variate from your true weight and setting Zwift to 100%, you will, if not careful, come unstuck very quickly outdoors when climbing. Keep it as real as possible on Zwift is my motto.

Great video Phil 👍 I’m not to clued up on the zwift trainer difficulty but I feel it would be good to have everyone on the same, I know that’s not possible with not everyone having smart trainers but would save the argument and make it equal for everyone no matter what 🤷‍♂️

I agree with 100% setting....Using Sequoia roads toboggans you can really feel the small climbs and descents and the changes are painful. Only for Pretzel and Alpe d'Huez I put 80% as I only have a 39x25.

Trainer difficulty is one of MANY factors that make indoor cycling a very different beast to outdoor cycling. To think that using 100% difficulty makes you ride realistically is to ignore all the other factors that are also quite important, like the inclination of the bike and lateral movement. There are (rather expensive) accessories that aim to minimize these differences, like the Wahoo incline simulator or the Saris platform, but those are just approximations to the outdoor experience-just like 100% trainer difficulty is. Wind resistance (or fan positioning) is also a thing that can never be realistic enough, which has a consequence of indoor riders spending more energy in cooling down the body than what they would do outside. The other point that seems to be frequently ignored is the difference between trainers. If I use mine at 100%, it becomes instantly very hard even in those ramps of Tempus Fugit, which are only 1% and 2%. It is very snappy, not a smooth transition at all, and it feels as hard as an outdoor change of incline from 0% to 4 or 5%. Could this be a matter of calibration? Certainly, but calibration will not make it "realistic", *only a better approximation*, one that still doesn't solve all the other problems, and it's certainly a disadvantage for races.

Obviously the range of undulations reduces with TD reduction. 10-12% becomes 5-6% simulated. That's why I often ride with a low TD - I can't be bothered to change chainrings, so I flatten the roads and ride in the big ring most of the time.

Nice Comparison. Keeping it at 100% most of the time to not flatten out the hills. Also to have the kickr climb move correctly. TD matters IMO on descends i spin out on harder descends quiet easily. Would be interesting to see a comparison the Rouvy i think they have a similar setting there and might even have your local climbs (if not you can upload them). Cheers!

did somebody say trainer difficulty?

I'm against 100%, certainly doesn't feel the same for me outdoors as it does indoors, and I mainly put that down to visuals. 'Seeing' a gradient coming at you, feeling the gradient as the bike moves under you and having to change how you sit on the bike because of it is what outdoor riding brings that indoor doesn't for me at any trainer difficulty to be honest. You know what I do, I change it day in and day out as to how my legs feel, just like a rider in the Tour would opt for different gears if a tailwind is forecast or a 20% climb. There's certain courses on Zwift that you are already at a disadvantage if you only ride on 100% trainer difficulty, the slider is there to be used in my opinion. Certainly no need to have everyone on the same TD either, other wise we'd be complaining that one climber has a smaller gear than the other going up Ventoux but they should have been on the same gear😅

Great stuff as always Phil. Quick tech question, what do you use to hold the iPad on the bike? Looking for a holder myself!

Great video Phill. For the longer climbs I think 100% TD is more realistic. On my lower end trainer 100% makes Zwift unrideable due to the lag on the rolling roads. Absolutely no question that the lower the TD the easier it is. I could hold 300 watts for the duration of a short crit race on 0% TD but couldn't last a lap on 100%...

I do the same. Just mentally I know it could be similar when I’m outside. My avg power is very similar indoor and out so I don’t fool myself that I’m doing well indoor but crap when outside if I use the default 50%.

Great vid Phil , just out of interest pre buying a watty , does it show your gears on screen Zwift or is it something you’ve added to show gearing in this video #Ride on

On downhill im at a real disadvantage and i have to almost push just as hard as on the uphill to keep up with those who have it on a lower setting. Also my highest gear feels too low for descending so i should probably lower it a bit.

Cracking stuff as ever Phill! How did you get on with the Pinarello Prince if you don’t mind me asking?

Totally agree with what you said about TD,, if people want to make it easier to climb on trainer and put in 50% that's fine , but annoying when they state it makes no difference ,,I wish Zwift would do racing where TD was @ 100%,, yes you can put a bigger cassette on but as IRL you will be changing gears alot more rather than sitting and spinning ,, I hate 100% TD but it has to been done to appreciate how hard climbing is ,, keep up the good work Phil and a fast recovery back to full power 💪

I recently did bolongna on %100 and found it quicker but that's because I run out of gears and had to push a slightly higher power just to get to the top 😁 so I would say for those that are not as strong on the hills to use %100 to become stronger outside so your muscles remember what it feels like to ride at 50rpm 👌👍

Until I get my rocker plate for my atom I will keep default settings I like to grind the gears just not on a stationary bike. Thanks for the clip though as spent the weekend pondering. Too much time on my hands I guess

A video on a wattbike fit would be good? Thanks for the content so far

I'm on Fulgaz and use the resistance scale for climbing to balance my gears on my smartbike. When I'm not out of gears i will set the resistance at 100%.

We should do some of my favourite climbs when you get over to Tuscany!

Nice comparison, Phill! Was this part of the Bro Science Series? ;) While I do acknowledge and agree with what you said, as to why TD doesn't really matter most of the time, I do still think that it does make a difference for how you deploy that power. Especially if you want to try to replicate realistic conditions and feelings outdoors, most of us don't have piles upon piles of cassettes to change between. Besides, you kept it fairly reasonable just doing 50 and 100%, but in my experience the people on Zwift who argue the most for TD not mattering are the people who ride and race at 0% TD, even if it may be AdZ or VenTop. Again, what type of gearing would you realistically need to throw on to do that cadence and power deployment up those climbs? Ps. What a camera man duo, Paul and Davide. Come to think of it...where do I bet on the next pickup for the WLC roster? ;P

I have tried racing on 100% alot and when i switched to 50% i started getting segment pbs out of nowhere. You can think what you want about this but its a fact that higher % difficulty inflicts more muscle damage which then makes it harder to put on a effort since you cant optimise your cadence 24/7 your muscles will get more tired. Maybe it doesent matter as much at lower power outputs but certainly for zone4-6 like in zwift races

Hi Phil, The bad thing about TD is that it allows for unrealistic gearing - The good thing is that you essentially can change gearing of your bike without physically changing the bike and I love that, without it Zwift wouldn't be for me - With my bike having 53/39 in the front and 11-28 in the back I would not be able to ride many of the climbs in Zwift - I use the the default 50 pct TD. On Some/many smartbikes you do not need TD as much because you can setup gear ratio on the go in the software, maybe also on your Wattbike.

My 'take' on this is that for real world long steep climbs, lower gears would be more appropriate.

Was having a discussion with my friends on Zwift this morning. I am wanting to be able to climb the hills in the lakes so i will be changing mine to 100% after seeing this and just use 50% in races!

The murky world of TD summed up perfectly. Training for real world = 100%, Racing or 'gaming' = 50%

Hi phil ? Thanks for another informative video!! 😊,could you please advise me what trainer difficulty you think I should be on, im 52 only been cycling since may 20! In the outdoors most hills feel like im towing a caravan going up them! W/kg swift is normally around 2.0-2.3😩, thanks for any advice you can give mate 👍

I use 100% and feel this is the most realistic. In real life you dont really change your cassettes depending on the ride you use. 100% replicates the gradient correctly and with practice your cadence inevitably improves with your fitness and knowing your gears. My zwift setup is an old 8 speed on a Kickr at 100%, so in a way using an 11 speed should be a bit easier on the road.

I enjoy 50%, personally. Power is power, and I always make it a point to stand on climbs in zwift (I'm a grinder, so I keep a lower cadence naturally). I find that the trainer has a small lag between going from a flat surface to a hill. 100% also makes you power more spiked, and not as smooth. 50% difficulty also allows you to keep your power up on a descent, which is not really feasible on 100% or outdoors. Depends on the kind of workout you want. Keeping a certain wattage over the course of 2, 3, even 4 hours on Zwift is really, really beneficial because you won't maintain the same constant power outdoors due to downhills and coasting. Gives you a better endurance base for those even longer rides outside where breaks are more common.

More armchair critique: it's time to get one of those articulated mounts for your voice microphone. The s/n ratio with fan noise is well, less than optimal. As it stands, your dulcet tones are nearly overwhelmed by the fan/bike noises. (My credentials as an audio engineer for 15 years notwithstanding.)

According to your findings, watts are not watts then because the same power is more difficult at TD 100%. How do we resolve conservation of energy with lower TD when power is used to determine how much energy has been expended?

I do agree that 100% TD is more lifelike but In my experience the TD makes no difference going uphill, but does going down. At 100% TD there isnt enough resistance to push 300W especially with steep slopes. However with lower TD there is more or no resistance so 300W can be maintaned. For races i do better with lower TD (typically 25%) but train with 100% for the realism.

When I have long climbs at or above 10% gradient (in the real world), I can't spin comfortably any faster than 76 rpm I have to get out of the saddle. Im glad to see I'm not the only one. I wish Zwift was just a bit more realistic

I just purchased a Kickr after years of using a basic Mag wheel on trainer and I was totally unaware that "trainer difficulty" adjustment was even a thing with regards to smart units until I was setting this unit up, I fully expected 10% grade to be just that unless your unit has a lower max grade available of course. I run a compact with a 32t-34t rear in the real world as I am not a whippet and I like to ride with a higher cadence and I know I will run out of gears on certain Zwift routes as I would in the real world and I will have to deal with it in the same way. I purchased the smart unit as I want to start doing some races and I am now in two minds as how to setup my unit when racing, Out of the box I set it up to be 100% TD as that will mean constant gear changes as in the real world and hearing folks say they are racing at vastly different TD has thrown me a bit, I do not want to get spat out the back due to a settings tweak "that everyone is doing", or are their races that use a standardised TD limits so everyone is in the same boat relevant to equipment of course?. Or as you say just set it to 50% TD when racing??.. Kinda ironic that I have come across this now as I didn't even look at racing using my old setup as I wanted to make sure I was on a level playing field to then find a pleather of seemingly acceptable tweaks that riders are using.. Superb vid BTW

So... same watts at both, more manageable cadence. Have my difficulty at around 60ish% and find Zwift harder than real world. I will say I have not compared it as thoroughly as you did. Feel like I push a bigger outside and work on higher cadence inside. That’s probably due to living in Florida!!

On 100% from day one (but i got a 12/30 cassette.)

How do you get Zwift to display your gear change up in the left corner underneath your power/cadence/HR data?

So what you are saying is that we will be out of the saddle a lot during the “Fred” haha... ok got it lol 😂

My takeaway from this is that road bikes are wayyy over-geared for the vast majority of users. Take me for example, 34/32 gearing and not at all fit, anything 8% or higher and I'm grinding in the 32, a 40 or bigger cassette would be better. spin to win.

when I decided to go from 30% to 100% TD, I lost 20 watts of ftp indoor, because the pedaling pattern is really not identical, even if the output power is similar. At 30 or even 50 TD you take advantage of the momentum given to each pedal stroke, while at 100 TD, it is necessary to press harder every time you pass the high point of the pedal. And on a 12% slope, that’s when you feel the weight of your bike (or abdominal fat!). I think the 300 watts really feel different on high percentages, between 30TD or 100TD.

Very nice video and explanation, I'm totally on the same page as you, I want the gradient spank the crap out of my legs just like it does outside. (having a Kickr climb makes it even more realistic) I think what seem to confuse a lot of people is racers saying they use TD to tweak their gear ratio, but in reality it's just as Zwift explains it... it's the gradient you tweak, so that 10% climb is actually only 5% at 50% TD... they just don't want to admit they make it easier for themselves 😝(I'm kidding of course, it's not a cheating if everyone can do it... right?) Like you say, A watt is a watt no matter what(t). Keep up the nice work!

the problem with zwift is it's hard to tell when a hill is coming up so you have to change gears really fast, outside you can simply SEE the hills. Constantly shifting indoors is annoying as hell.

Phil the Supreme...Lord of Zwift ,Leader of all City&Tower Bridge bike lanes,Grande Master of Tesco 1/2 baguettes with tuna...how is your recovering post procedure going...when can your vast audience and as well your sponsors&investors expect a good vlog with nutrition guides??? your clients are getting quite nervous as their sales have dropped considerable due your very poor PR performance of their products...greetings to Jayne as well.

Please,where can i find this course on Zwift?

The real problem is that the "climbing setups" your describe are still too hard for normal people, and they're way better than they were in the 1980s (42x21 gaaaaaa)! Things improved dramaticaly when triple chainrings became common in road bikes in the 90s, but never really caught on, and was a distinctly unfashionable "low end bike thing" by about 2005. The compact setup with the lowest gear 34x30 is not bad, but as you show , still not quite enough, results in more chain drops when shifting the front (unless you have Di2) than the triple with a 30 granny ring mated to a cassette with a 25 or even 28 tooth big cog. An now the push to 1x setups, avoids the chain drops, but do normal people understand they need to sacrifice top speed and swap in a smaller chainring to be able to climb? Do bike shops tell people? Nope, they do not. Ride what the pros ride and suffer! The Zwift difficulty slider absolutely lets people live in a fantasy world where their bikes have lower effective gearing. Maybe that will help change things in the real world?

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