Darth Lefty 

I'm looking at using Zwift and trying to figure out all the things that I need.

I had a shopping list here when I started writing but it was getting to be a mess. So let me just ask, what do I need? Right now I don't have a trainer, smart, dumb or otherwise, and none of my bikes have any sensors. So it could go a lot of different directions and I don't think there's some optimum minimum amount of stuff I can buy. For instance I can think of a lot of scenarios where sensors could go either on the bike or the trainer, depending how smart the trainer is.

I have, bikes: a single speed gravel bike that could be set up 1x11, but limited to 38t front, and might bear mentioning a 73mm bottom bracket shell, and a thru axle; an old steel 14-speed racing bike with pretty tall and narrow gearing; an even older but very nice for its era 10-speed with even more limited gearing. Electronics: a Windows 10 laptop; a Roku TV; an iPhone and Apple Watch; a fan.

I have at least figured out that I can get Zwift to talk through the phone to the HRM on the watch, and I'm guessing that means the phone is the head unit for all the other sensors too.

Can you do smart bike / dumb trainer where you wire up your bike completely with power and speed and cadence? (I wouldn't mind having an excuse to buy a Stages XT crank arm.) But then you need a speed sensor too? because no GPS

Clearly you can do a dumb bike / smart trainer, but then what is still missing?

What kind of gear range bike do you need? Same as you would want on the road? Clearly I've made some really limiting choices in my bike acquisitions...

surak

You only need a smart trainer. Alternatively, a dumb trainer with power meter OR speed sensor. You will get the best experience out of Zwift with a smart trainer, because then it will be simulating the terrain and environmental effects like drafting and momentum. Any recent smart trainer will support QR and thru-axle. With a dumb trainer and power meter, your watts will translate to speed in Zwift, but you lose out on the feeling of immersion. Using a dumb trainer with a speed sensor will be similar except the power estimates (zpower) will be a guesstimate and can be often wildly inaccurate.

Your top gear is more important in Zwift than lowest gear because there Zwift has a difficulty setting that scales gradients. The default difficulty is 50%, making hills half as steep. In the extreme you can set it to 0% and make everything flat, which sounds silly but can be useful for recovery rides. From the bikes you have, the 14 speed would require the least fuss, probably only needing cassette spacers if you choose a direct-drive (superior but more expensive) smart trainer option. If you don't mind spinning out on descents, setting your SS up 1x11 would also be fine. I used my 1x11 bike with 40t chainring through the summer on Rouvy and only missed taller gears on descents during races, but Rouvy doesn't have a difficulty setting in that mode and TBH more often I was simply too tired to pedal after going deep on preceding climbs instead of truly spinning out.

If your PC has Bluetooth 4.0 or newer, the trainer will connect directly to it without needing to go through the companion app. Otherwise, your options are the companion app or an ANT+ USB dongle.

jpescatore

It is possible to outfit your bike and a dumb trainer with sensors and use Zwift, but I decided I wanted the full experience and didn't go that way. So, for smart trainers:

There are two inputs you want for Zwift, power and cadence. All smart trainers give power, some also give cadence. If you don't choose a trainer that gives cadence, you need a cadence sensor on your bike. There are some that just require one doodad installed on your one pedal crank arm (like the Wahoo cadence sensor), others require a magnet in your spokes.

There is one output from Zwift - the resistance control it sends to the smart trainer. Zwift has a list of Zwift-compatible smart trainers here, and there is a good article overall on smart trainers here. The bike you use may cause you to look at wheel on trainers, if your bike's gearing isn't supported by the trainer and you don't want to mess around with spacers.

Then you need something to run the Zwift app on - PC, laptop, tablet, phone, Apple TV. Zwift gives you info on that here. You will probably also want to run the Zwift companion app - that runs on any smart phone or tablet. You may want a separate monitor.

You will probably want a fan - nothing special there.

Beyond that you may want to put a mat under the trainer, and something over your top tube to catch sweat.

After that, you just need to get on and pedal!

Thomas15

Darth,

A bit of Zwift and trainer theory....

When I stared my indoor adventures just last year I didn't have the sense you have to ask the questions you are asking. Instead it all sort of evolved and I made a quick study of things and I think I also had a bit of simple dumb luck.

If you want to make it very simple then a smart trainer is the way to go. You will need some sort of electronic device to actually run the Zwift program and an internet connection. If you are using a smart phone then it could be said that the phone is your head unit but all of the data is displayed on the same screen that shows your avatar, other riders and the road you are riding on. Since that screen (a phone) is soo small I personally looked to put the display on a flat screen TV. I'm not sure how you do that with a phone but it is possible i think. I have a laptop that runs windows 64 bit that is connected to a flat screen via HDMI, the trainer is connected to the lap top using a dongle. At any rate there are tons of youtubes and zwiftinsider.com showing the many ways to connect to Zwift.

Again a smart trainer will make it simple but there is a cost factor. Most smart trainers are fully supported by Zwift.

As I said I got lucky when I started out, not knowing anything, I bought an old Kinetic Road Machine used on CL for $50 I added the InRide3 sensor for $40, the Kinetic rear wheel skewer $15, a dongle $20, a front wheel riser block $8 and a trainer tire about $25 So for $150 I was all set. While the Kinetic Road machine with InRide is a dumb trainer is isn't totally dumb because Zwift supports this particular trainer. One of the few dumb trainers Zwift supports, most are not supported.

A fluid trainer by design is harder to pedal the faster you pedal. So, if I want more power in watts for the hills, I need a big gear to keep my cadence within reason as I cannot ride at 150 rpm for very long, if even at all. A big gear eats up big watts so this gives me a realistic amount of resistance when riding, a good hill climbing simulation.

What that means is (with the supported InRide) I get the advantage of a power meter/cadence/speed using a "dumb trainer" which is great. In practical terms, when I'm on a Zwift hill or mountain, the support I get adjusts the speed to the conditions which means that if I'm on a 14% grade, I need to put enough power to the pedals to actually pull the grade at a reasonable speed. This means either a low gear with a high cadence which is what you would do outside, or mash a high gear with low cadence, the opposite of outside. Keep in mind that watts per kilogram are watts per kilogram regardless of the gearing. At my weight (61.5 kg) I need about 180+ watts (2.8 w/kg) to pull a 12% grade at 5 mph give or take, so I usually select a high gear and mash it. This sets up a realistic situation on my trainer that is similar to what I would be doing outside on a similar hill from both needed power and workout effort. I have seen people go from a similar Zwift set up to mine to a smart trainer and actually say that it is harder to ride what I have than a smart trainer on the big hills. I say all of this to make a point. You can put inexpensive cadence and speed sensors on your bike, mount to any dumb trainer and it will work, true. But unless it is supported by zwift (not just sensors recongnized) you will not get the full advantage of a power meter which is much less than ideal.

But still, with what I know now if I were doing it all over again I would spend the $500 and get a wheel-on smart trainer. But I'm not going to replace what I have because it works, works actually well. If I ride 12 miles on a flat route on Zwift, for example in the desert in Watopia, 12 miles with a total of 50 feet of incline, I can select a fairly easy gear and cruse along at 22 mph nice and easy, heart rate 130 bpm, easy cadence and generating 2.0 watts/kg, hardly break a sweat. It will take me about 35 minutes to do this ride. However if I select the Alpe du Zwift, same number of miles but 9 of those miles are at 9% grade, I need 2.7 + watts/kg, my heart rate will jump to 170 bpm, my cadence will be +/- 60 rpm, the sweat will be pouring off me and it will take me an hour and fourty minutes to complete the same 12 miles at 4 mph. A dumb trainer with just garden variety sensors will simply estimate power in watts and probably not make you work anywhere near that hard on such a climb. Once I hit the top of the Alpe, just like outside I can literally coast back down at 40+ mph, I can get off the trainer and take a break and the bike, all by itself will in 20 minutes be at the bottom of the mountain.

So, yes, even with a properly supported dumb trainer on Zwift, I have to do the work and select the proper gears at the right time, just like outside. If I'm in a race and not paying attention and we suddenly hit a hill, If I don't react accordingly, I will get stomped on by the other racers, same as on a smart trainer and same as outside.

So that is some theory, not a shopping list, not exactly what you asked for. I just wanted to try to explain some of the practical differences between smart and dumb trainers. A dumb trainer not supported by Zwift but using power meters will also work well but given the cost of power meters, no one is going to buy them just to use a dumb trainer on Zwift.

You will also want to wear a heart rate monitor.

jadocs

Get a smart trainer.

A dumb trainer with speed and cadence is going to grossly overestimate your power....so if you want to replicate real life and have it translate to outside, you need a smart trainer. You also do not benefit from reacting to elevation changes. You will be in for a rude awakening if you try to use your new found power/speed IRL. 95% of people who use dumb trainers can be spotted in the Zwift FB community with completely unrealistic FTPs and postings of conquering Alpe Du Zwift in under an hour. If you are competing with yourself...that's fine, but don't kid yourself by thinking it's even close to being real.

A dumb trainer with a power meter...yes your power will be accurate, but you are not benefiting (your body is not being conditioned) to react to elevation changes. You are responsible for your own resistance by changing gears or manually increasing the resistance on your trainer. It's not remotely the same thing, I promise you. You will realize this when trying to spin up a steep hill IRL and your HR skyrockets beyond anything you have seen in Zwift. It's a lot easier to spin up a mountain when you are in charge of your own resistance. (refer back to my conditioning comment above). If you're going to spend the money on a power meter, you might as well just get a smart trainer.

So my opinion on things to get:

- Smart trainer
- HR monitor
- Cadence sensor

billridesbikes

You can run Zwift on your phone, but it’s much more fun if you stream the video to a large screen TV. It’s much more impressive that way and better for group rides or races because you can pickup on visual cues in-game better.

If you can afford it, the best option is a wheel off smart trainer where Zwift can control the resistance of the ‘bike’.

caloso

I did my first winter on Zwift with a 20-year old Nashbar fluid trainer and my road bike with a Quarq PM. You don't need a speed sensor because all Zwift needs to simulate your speed in the game is power (plus your weight and height, which you enter in your profile). The Quarq (and I assume most PMs) also transmit cadence, which is nice to have if you do workouts with cadence targets, but the game works without it. Heart rate is also nice to have if you're tracking that, but again it's not necessary to make the bike move in Zwift space.

Now I have a Kinetic with the In Ride sensor, which does power and cadence on its own. That allows me to use any of my bikes. When it's calibrated, the In-Ride is very close to the Quarq. Impressively so. I think it's a great bang-for-the-buck. You don't get the feedback of a smart trainer, but that may not matter to you. Personally, 90% of the time I'm on Zwift it's to do a structured workout, so all I care about is hitting the wattage and cadence targets.

As for my set-up, I use an iPad to run the game. I have it on a music stand next to my bike and that's connected to a flat screen TV with a Lightning to HDMI cable.

Darth Lefty 

Welp. Apparently SWMBO is at least kind of on my wavelength, and already bought me something that is arriving tomorrow. (We had talked about setting something up before but in no detail.) So I guess I'll take whichever path that leads.

She says it's cheap.

Thomas15

I agree with jadocs overall and I hope what I wrote is not confusing or an considered an advertisement for anything. For sure get a smart trainer.


I also find amazement in those that zoom up the Alpe at 5 w/kg. It is interesting to note that when I do a race, in particular one that is a cat race (I'm cat C my ftp is 190) that half of those that took the time to do the race are not registered with Zwift Power and linked to strava. Why? Because they don't want to get DQed for cheating which is exactly what they are doing. I think but cannot prove but I think more of them are weight doping rather then using a dumb trainer to fudge some zpower numbers. Even on a smart trainer you can really get lose with power numbers. A friend of mine has a tacx vortex flow it can only replicate 6% incline, set that on < 50% then you got 3% max , set weight to 50 pounds lighter than you are and skip the HRM and get a partner to share the riding. Zwift Power weeds out most of them out but of course not all of them.


I started using my trainer and Zwift at the same time, this was last November. At that time I had about a year of bike riding under my belt, could ride 60 miles flat but I could not ride anything up hill, a 6 mile ride with 500 feet of ascent would force me off the bike and walk. No kidding.

I'm in the mountains, as of this spring, my regular IRL training ride has become 26 miles with 3000 feet in ascent. It is true that a trainer doesn't replicate every little aspect of IRL riding. But regardless, if you crank out the watts you will get in better shape. My first ride after last years long winter, on the hills IRL really didn't go as well as I wanted. I think because no steering or balancing and shifting on my trainer is different. After I got my sea legs, three ride into the season I started riding with a semi-local club. I did many weekly club rides with experienced riders, 25-35 miles, 1800-3000 feet ascent again with seasoned riders and was told numerous times that I was a strong climber. After a few rides I was the one waiting at the top. This from a guy that 6 months earlier couldn't ascent the 200 feet on the road I live on without having my legs and heart explode. My best time on the Alpe, from the foul line after the curtain to the spinner is 67 minutes, usually it's about 75-80 minutes. I have not to date exceeded 2.9 w'kg average on any zwiftpower results, I think the highest balls on effort on a short steep incline like the lift in the London train tube is about 400 watts (what 10 seconds?) certainly not much more than that. Last winter Dec to April I rode the Alpe about 35 times, so I worked very hard on climbing and I'm happy with the result IRL. This using a mildly ******** trainer. So yes, absolutely I would get a smart trainer if I didn't already have a trainer or if I had one that is of the many unsupported dumb trainers out there.

Thomas15

I just got a pair of Garmin Vortex 3 PMs and while I haven't compared them to the curve of the InRide, my unofficial comparison InRide to IRL with the Vectors is quite similar. I get on the Vectors what I expect to see, if anything the vectors show a slightly higher output than the trainer. But usually my average HR is slightly higher outside also.

mstateglfr 

I didnt realize speed and cadence typically overestimates power. I have a dumb trainer plus speed and cadence and it gives me eerily similar power numbers to what I expect based on having used a smart trainer, smart spin bike, and a left arm power meter outside.
My FTP on Zwift is right in line with what a smart spin bike and a power meter has shown.
When I race, I typically finish in the 75th% of D, always under the w/kg requirement, and most everyone ahead of me used smart trainers and is way over the w/kg range for D. I mention this because its funny that dumb trainers would be what is noticed/complained about on FB for Zwift when gobs of people race in the wrong division for whatever reason.
Oh well.


I dont follow this at all. When I am on flat road in Zwift, I move at 19-23mph lets say. And when I am climbing a 8% hill in Zwift, I am moving at like 4-8mph.
If I stay in my hardest gear and pedal at 70rpm, I am moving slowly up the hill. If I move into an easier gear and spin at 90rpm, I am moving slowly up the hill.
Either way, I am moving slowly up the hill since Zwift takes my speed and cadence into account and adjusts accordingly.

This tracks closely in real life since if I climb an 8% hill outside, I could go slowly up in in a harder gear at a slower cadence or I could go slowly up in in an easier gear at a higher cadence.

What am I missing here? It appears you are saying hill climbing in Zwift with a dumb trainer isnt realistic, yet my results sure seem realistic- I go slower on hills.

spelger

Can you explain why this is so? and why it is an overestimation? i assume it is becasue of the lack of grade data but am not sure. 10 mph @ 100 rpm @ -5% grade is less power than 10 mph @ 100 rpm @ 5% grade.

Marcus_Ti

Nice. Once we know what toys you got we can say more. As for indoor virtual training, it depends on your taste.

Zwift is basically the latest in 1990s riding video games. Which, if that motivates you, great. Prices keep going up, and it is a popular platform

Rouvy is basically riding outdoors with IRL footage of routes.

Then there are the plethora of structured workout platforms.

caloso

I had the same question.

atwl77

I'm not the one who made the claims, but I believe this may have something to do with the flywheel effect. On a dumb trainer, the faster your rear wheel spins (for example, to generate more power you'll shift to a heavier gear which in turn makes the rear wheel spin faster on the trainer), the flywheel will help keep the wheel spinning longer. This is great for trying to simulate riding on flat roads, less on climbs. So you are getting some extra "help" from the flywheel effect if you use a dumb trainer with speed sensor for virtual climbs.

Whether that extra help is negligible or not, I can't say, but I think this will most likely depend a lot on the selected gearing, the size/weight of the flywheel itself, and whatever manual resistance can be adjusted by the rider.

Thomas15

There are different dumb trainer designs but a decent one will have some kind of resistance unit (fluid or electromagnetic), that will provide the resistance and the flywheel is there to add realism to the trainer feel. On my trainer, without the flywheel the bike wheel would stop almost as soon as I stopped pedaling due to fluid chamber resistance. The flywheel keeps the speed at a realistic coast that one would expect IRL but it doesn't make the job of pedaling any easier.

Thomas15

That makes three of us.

I went through a period of time where I was trying to scheme a way to replace my trainer with a smart trainer. Back and forth back and forth reading everything I could find on the subject. I finally concluded that the only real reason I would replace my Kinetic would be so I could tell all of my friends and neighbors that I had a smart trainer. On a smart trainer you have to shift gears so really no savings there. But at the end of the week watts per kilogram are watts per kilogram. If you are producing the desired or required watts at the desired cadence then your body doesn't care if your trainer is controlled by Zwift or if Zwift determines your speed based on rider weight, power produced and gradient. .

mstateglfr 

The example you provide would occur if I used a Wahoo Snap(smart trainer). The flywheel would spin faster if I generated more power).
As for the flywheel helping to get a rider up a hill, I definitely havent experienced that. The flywheel on my bike simply keeps the wheel rolling for a short coasting time. If I stop pedaling on a hill climb in Zwift, I quickly slow down, even with the flywheel. That is opposed to if I stop pedaling on a downhill in Zwift, I continue to coast in the game.

By no means am I declaring any of this is relatable to real world riding, but I struggle to understand the stated concerns about a dumb trainer on Zwift as none of them apply to my dumb trainer when I ride Zwift. I am for sure not getting any assistance up hills(other than the computer algorithm that everyone default benefits from).
If anything, I would say Zwift shows me as faster on the flats and slower on climbs compared to real life. Im going for a ride this afternoon and I wont average 23mph on flat road and I wont average 4mph on 8% climbs.

Maybe I am just misunderstanding.

Mounttesa

Watts is watts regardless of trainer type. But the feeling of climbing at X watts vs. pushing along the flat at the same watts feels way way different on a smart trainer. A climb feels like a climb.

caloso

That I can see.

spelger

i think this is why wahoo came out with the kicker climb. i don't have one and it would be pretty neat but not in mu budget. i have this dream of using a piece of wood under the front tire. its only a dream because i only remember when i'm on the trainer and "heading" up a hill. one day i'll remember. a 2x4 should be perfect for a 5% grade.

caloso

I have a cinder block for when I do Alpe du Zwift.

sarhog

This article may clear things up for those of you with questions IRT smart vs dumb trainers. Smart trainer vs dumb trainer article on Zwift Insider

caloso

Thanks. That was a good explanation. This explains why my workouts keep encouraging me to spin up before the short hard intervals. I guess it's easy to bog down in erg mode.

Darth Lefty 

The difference in feel between pushing a low gear up a hill vs pushing a big gear on the level vs. any old exercise bike in the gym is noticeable and easy to understand why. The outdoor bike is either mostly hill or mostly aero drag. The exercise bike is pure rolling resistance. You can feel the difference. Does a smart trainer not, somehow? What makes the difference?