Schwinn IC8 Spin Bike

Hi there, just stumbled upon the thread; happy to have found some people with similar questions.

Amazon Germany redirected me to Spofact/Ulm ( for German support which responded quite fast, but they did not acknowledge any problem so far …

My (limited) experience so far is

  • Zwift does connect as a power source + cadence (not as controllable). (controllable shouldnt make too much sense as the Schwinn IC8 is not a smart trainer?!)
  • speed / distance readings from the console are looking generally too high - very slow riding (30 rpm) on light level 35 already results ~ 24 km/h. with 60 rpm on level 35 ~ 36 km/h.

Update 1:

  • Zwift readings on level 35 / 60 rpm: ~210 watts (directly shown in the bluetooth/sensor screen). Speed: ~35-38 (test on sections of mostly flat volcano track).

Update 2:

  • Took the measurements from another bike. Same results.

Thank you for your post. Could you please provide the contact data of Spofact/Ulm? I also would like to contact them. I guess it will help if more People Show up with the same Problem. Thanks

This explains why calories are off the charts high as well. They are likely doubling output power and in turn the calorie count is inflated.

I am not sure they are generally doubled. Maybe on lower speeds? Generally it more feels like +30% / +50% (???). Might depend on resistance level and rpm.
@Olaf: Added adress above.

This is pretty close to my experience as well. Though in my cases the distance seems to have very little to do with the speed. At first I thought it was doing the distance in Miles and the speed in KM, but after making the console display in MPH it still didn’t line up. Would get wild readings, like an average speed over 20MPH, but a distance of like 6 miles after an hour (edit: this is all on the bike console, not on Zwift, which I know would show different distances based on elevation, etc.)

I think at lower resistance (I do like 24-30) and RPMs around 80 I was probably around 270 watts, which seems high (but I have no experience in any of this tech or biking in general, so I’m only relying on the fact that I was passing everyone. Which seemed ridiculous.) I think it’s 50% high may be stretching it, but I could see 30% or more.

Otherwise I really like the bike, it rides great and fits in my tiny Brooklyn apartment, so I guess I’m going to find some power pedals and use those instead. At least when I can eventually afford a road bike I can swap those and know the readings are all going to be the same.

It is a great bike. I hope they can resolve this issue as they sold it as being able to do this stuff correctly.

Found something that might be useful to all of us (nice Article concerning power measurements):

Tak a look at this

Here are rough estimates of the wattage required for you to hold particular speeds outdoors:

  • 25 kmph (15 mph) – 92 watts
  • 30 kmph (18-19 mph) – 143 watts
  • 35 kmph (21-22 mph) – 212 watts*
  • 37.5 kmph (23-24 mph) – 254 watts
  • 40 kmph (24-25 mph) – 301 watts
  • 45 kmph (28 mph) – 415 watts

So if you’re unsure if your power numbers are accurate in Zwift, just find the speed above that you can hold outdoors on a flat ride going all-out for 20+ minutes. Then see if that wattage matches what you see in Zwift when you’re giving it everything you’ve got!

If you aren’t a trained athlete (let’s say you’re in your first year or two of serious cycling) and you are of average size, chances are very slim that your FTP is anywhere above 300 (for males). Chances are it’s close to 200, and maybe 250 if you have good genes or have been training for several months. Many riders will be significantly lower than 200 at this phase, and that’s OK too!

I know what kind of effort I have to put in to hold 35 km/h on my training bike in the summer (which is roughly 210 watts accordings to the above).

Compared to that, 210 watts (level 35 on 60 rpm) on the IC8 is a walk in the park, probably easy to hold > 300 on the IC8 even for a beginner :slight_smile:
-> not realistic.


Keep in mind. The speed and distance on your console doesn’t account for any uphill/downhill, drafting or freewheel. Yesterday i was riding at 24kph on the flat during a cool down and my console showed 23.8kph so it was pretty close. My distance on zwift was 30km, but on the console it said 46km. That was because i was climbing on the mountain route. However the power output almost makes me look like a professional cyclist. I can do >300W for more than 30mins with a heartrate of 135avg.

So I put the new console I received onto the bike and no change on Zwift. I need to contact them again because it is clear it is the power meter causing the issues.
I love the bike so will not return it but very frustrating not to be able to get accurate readings.

I heard in another thread on facebook you can connect the bike as a power controlled and then switch it to a dumb bike in settings. I will try to find the post today.

just, looked it up in facebook group. I don’t have zwift installed yet but the guy said you make your trainer “dumb” in settings to change the watts to a normal reading. He said it was changed to a “non-smart bike” and it got fixed. Not sure if it was an android or ipad user. See if there is a setting like that to fix it.


How would that work what power curve will Zwift use for speed, if it does not know on what resistance setting your bike is set?

Hi Gerrie, I have no idea the validity of the comment nor what zwift is actually looking at. However, the ic4 console outputs calories. Based on that output alone zwift should be able to easily calculate power. Note that the speed, distance and calories in the console already factor in the resistance setting.

I didn’t get any takers last time but just to throw it out again. I have noticed that the speed and total distance reported on the ic4 console do NOT correlate with each other. Anyone else see this issue? To me this is part of the same problem as the power output problem but it’s much easier to explain this console issue to Schwinn rather than argue with them about what Zwift reading should or should not be.

There is a recent review from Jan 2 on amazon that seems to summarize all the issues.


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Hi Chris,

So Zwift need one of two things to make the avatar move. Actually to calculate speed.

  1. Power number in watt broadcast from the trainer.
  2. Speed that zwift can convert to power using a know en powercurve based on a set resistance.

My guess is the spin bike has set resistance values and they programmed a power curve for every resistance value and from that they calculate the power.

I did this also. Wattage is wildy inaccurate. I find my self slowing down not to KOM anything because i know for sure it’s not correct! Shame i was just getting into Zwift too.

Hi Andy,

Checking back in with my Customer Support Journey…

I have the Schwinn™ IC4 / IC8 and Bowflex™ C6 Bike. My power readings are too high for my fitness level. I contacted Zwift and they said they couldn’t help me because the bike was unsupported. (As stated in post below only the Schwinn AC and the Cruiser are supported.) Zwift also instructed me to use speed and cadence outputs from the bike in the meantime. I do not believe this is possible with the IC4.

I’ve called Nautilus, the parent company twice. The first time I got nowhere. The rep did not understand what power was and said to contact Zwift. The second time I asked more specifically how to calibrate the resistance knob/console. I believe this is where the problem stems from. They sent me calibration instructions via email. He was walking me through them and I couldn’t get passed step 3. My rep then said the engineer he consulted said that might happen and that I got a bad console. So they are sending me out a new console under the warranty. However, I’m still not confident this will fix the problem, but I’m hopeful.

So if you are having power reading issues you may want to call and request the calibration instructions. I’ll try to screenshot the instruction here. I’ve seen elsewhere that the console algorithm for watts may be incorrect and they fixed it in later releases of the console. I’ll check back in later if this fixes the problem of high wattage readings in Zwift.

Here are the calibration instructions:


Thanks for this Matt, I’ll try it tonight as I received a new console through the post but same watts issue being too high!

Yes, let us know if it fixes the problem. I’m hoping they fixed the algorithm so it’s more accurate. The problem is that it hard to know with out an expensive power meter to compare it too. However, you’ll know generally if you are back down to normal range for your fitness/cycling level.

Also, the Nautilus CS Rep advised trying to use the console without calibration first, fyi.

It sounds like Schwinn is saying this was an issue with calibration / faulty consoles that may now be fixed on more recent machines.

If so, is there anyone that DOESN’T have the power reading issue? Perhaps someone that recently had their IC4 delivered?