Hi. I am James.
I just started Zwift. I do not have a smart trainer, so I have a basic set up. I cannot afford power meters, so I only use the bike and speed/cadence/heart sensors. Overall the experience has been positive.
I do have a concern about climbs, though. Obviously, I do not have any feedback between computer and trainer, so I do not feel the climb. However, I notice on the game my cadence and speed will drop immensely when starting a climb, even though my overall cadence has not changed. To wit, on a recent climb, my reported cadence fell about 90%, while actual cadence stayed at about 80rpm. A noticeable drop in estimate power, as well. If I change gears and speed up my cadence, there is no change in on-screen speed or cadence.
Is this part of the game? The machine figures that going up a hill will slow you down anyway, so the game forces you to slow down? IRL I love climbs for the endorphine high I get at the top. I know this is virtual, but coming to a near complete stop in the game takes me out of the experience.
Barring droping a few thousand dollars on a smart trainer and decent set of power meters, is there a workaround? Or, just ride the flats?
Thank You
I cannot comment on your non-smart trainer. You do not need a power meter with a smart trainer (although you could use such meter if you wanted to). All you need is a smart trainer. Some of the best wheel-on trainers are around $600-800 (maybe less, I haven’t checked in a while. The “direct drive” smart trainers start around $950. You could research which one suits you and your budget best.
Good morning @James_Bohling - welcome to zwift.
I am a bit confused by your problem but lets see how we can help you.
You say your cadence drop on hilles: so cadence is only the speed of your pedals in RPM , zwift does not do any calculation with your cadence, it only show what your sensor sens it.
Going uphill your virtual speed will go down but your power number should stay the same, so you will have to change gears to get more wheel speed and that will give you more power.
What I am saying is that when I am riding a flat in Zwift, then on the screen with Zwift it will show my cadence, speed, and power. On a flat at a decent clip it will show my cadence at about 90rpm, my speed at a certain number, then my power. I do not have a power meter, so I am guessing that is an estimate. I am also using a dumb trainer, so physical real resistance is not a factor.
When I reach a hill in the virtual world, those numbers drop substantially, even though I am physically still peddling at the previous clip. My cadence has not physically slowed down. The avatar and on-screen numbers, have.
I get that maybe it is forcing me to do a harder effort, but spinning faster regardless of the gear, does not change the speed, power or other numbers represented on the screen.
Do I need to invest in a power meter to be able to get a good experience with a dumb trainer, or just invest in a smart trainer to get the best experience out of Zwift?
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Zwift speed for a “dumb” trainer is calculated in the following way (really need to copy this somewhere).
Zwift takes your rear wheel speed and the power curve of the trainer you have chosen within the Pairing Screen and converts that to watts. With those watts, the in-game bike used, weight enters, height entered, in-game elevation changes, in-game drafting your in-game speed is calculated. So if you hold the same watts, going up a virtual incline your speed will drop and going down your speed will increase.
Zwift doesn’t not adjust your cadence in anyway, it just uses what is being broadcast.
What are you currently using for a cadence sensor?
No you don’t need a power meter to have fun on Zwift.
Zwift calculate Power from your wheel speed using the power/speed graph for your specific trainer.
So while your wheel maintain the same speed your power should be the same.
What Trainer do you have?
Cadence, Speed, and HR are all Polar and all Bluetooth. We do not have Wahoo in Taiwan. Have to order from Amazon and pay a tariff.
I am using a Giant mag trainer that is about 10 years old. It has a useless adjustable tension cable (if it does work, it is very minute). No power meter.
Would interference play into it? But this issue I speak of only happens on hills. The wifi in that part of the house is spotty, so I connect my Macbook to internet via my phone’s mobile network via Bluetooth. I found the only issue this set up causes is it does not allow my ride stats to show on my.zwift or upload automatically to Strava. But that is a separate issue.
Did you set the tension cable to the correct number when you did the setup in Zwift.
I had a look at your last 2 rides, and it look like you have a lot of dropouts from your sensors, I see the power goes to Zero all the time. This may be caused by to many bluetooth traffic.
Can’t you create a hotspot on your phone and access it from your Macbook over WIFI, that could free up some of the bluetooth traffic?
For whatever reasons, I could never hook up the phone as a hotspot. Or maybe I have no idea what I am doing. Today I tethered the Mac and phone together and seemed to get a steady internet as everything uploaded.
The tension adjust cable for the trainer either does not work correctly, or the whole thing does not work correctly. At the highest tension setting on the dial, I can still spin out on it. I adjust tire tension as follows…let the roller contact the wheel then 5 COMPLETE additional turns.
Those dropouts are probably me stopping. 
I do that as I make adjustments to the ride.
Maybe I am just making this more confusing than it is. Would it be fair to assume that the program takes the numbers from the sensors, does some voodoo with them and displays them as they would appear if I was actually going up a hill? Even though my pedal and wheel speed are not slowing down on the bike, in the game they are since I am going up a hill. If I shift into a higher gear then I am making using more power. I did notice my cadence went up in the game the higher the gear. I dont know. It is a fun experience all the same. Thank you for hanging with me.
This may be an old post, and I may be over simplifying your question a bit so I’m sorry if that’s the case. I ride with a “dumb” trainer and when going up hills I shift into the big ring and into harder and harder gears as the elevation increases. Basically I am simulating the hills with my gears so I’m doing the opposite of what I would do if I was riding outside. This keeps my speed at a pace that I won’t stop because of the slow speed. Same for negative incline I switch to easy gears and spin fast like I would as if I’m going downhill outside.
I hope that makes sense and helps.
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And i thought i’m the only one facing this. Thanks for highlighting this James.
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I have had this issue with a btwin inride 500 fluid trainer (dumb trainer) with btwin speed and cadence sensor. I get dropped on climbs and can’t keep up as the fluid trainer itself is designed to auto increase resistance the harder I pedal. This makes the traditional approach to climbing hills with a classic trainer (cycle harder) of little use. Also as I increase effort on flats, my watts output peaks at about 90 rpm in a 39x14 gear. Anything harder then that and the watts drop. This trainer is good for a decent workout and is quiet but not racing.
Hello,
I have just come across to Zwift after using the other lot that make you “Suffer…”. I enjoyed using them but wanted a group ride with some interaction. I am having the exact same problem with my setup. I have a Tacx flow basic (Not Smart) it is fine on the flat but as soon as I hit an incline the speed drops to 3kph regardless of the effort I am putting in and despite the fact that my Garmin is telling me I am doing 10-12kph. I get the fact that the Garmin is not taking into account the fact that I am on an incline so speed would drop but on Zwift when I hit ANY incline I come to a virtual standstill (excuse the pun).
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Hi Mike,
Thanks for the explanation very useful. However what it does not do is Offer a solution. What i am thinking is that I should set my height and weight at the lowest settings in order to keep up? I am an honest rider and feel like that would be cheating a bit? I wonder if iI try and calibrate the trainer to Zwift as the key elements are that I virtually stop on an incline and descend faster than a pro!
Hi @Stuart_Moss2.
If you look at the Sample power curve in the link that Mike posted you will see a wheel speed of 10km/h is about 20 watt. if you want to climb faster you will have to get your wheel speed above 30km/h. I would suggest changing to your big front gear and the small back and see if you can get the wheel speed up.
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I am glad to see that I am not the only person here with this problem although the only thing that is really noticeable for me is the cadence. On the steepest climbs it will drop to as low as 15 even though my actual cadence is way higher. My power output remains the same.
I haven’t seen an actual solution here so am hoping there is maybe some fix that has come out since last year when this was first posted
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Hi yes I have the same problem on tacx santori. As soon as I hit a hill the RPM drops on the game but in real life my cadence has not changed.
