Hi Terry. Yes- for the 0 setting I followed the Nautilus manual’s instruction.
You can use Zwiftpower to do duel recording and that will give you a good picture of accuracy.
Hey all.
Do we know were this is at currently? Just purchased an SC8 here is Australia for the sole purpose of using on Zwift as advertised. After reading this forum is seems i made a bad decision. However it does not look like there are allof of options out there for spin bikes compatible with Zwift with accurate power readings. (yes it needs to be a spin bike not a trainer) my wife uses it too.
I had a little go last night and was getting about 250w at roughtl 35-38klmh at about 60-65cadence. Is this sounding like it is right?
The model on the back of the computer says it is version 10. I noticed that others on this forum advising that the replacement ones they received were model 3 and the newest?
It appears that the new computer has not helped? and calibrating the machine gets you closer but not fixed. I am in a position to potentially get a refund however i am not sure what other bike to choose. I like the Schwinn and want to stick with it, so hoping there is a solution?
Cheers,
Thank you all for your posts on this topic. We bought a schwinn ic4 last November for use during the pandemic on zwift. I was not in great shape at that point and by wattage readings on zwift I fell solidly into only D cat rides. I realize this has been a long standing issue but I felt like the readings we’re pretty accurate. After six months of training I moved into C cat and just barely broke B. Now I’m thinking of racing too so really need to confirm accurate power (I know power pedals are the only way but can’t afford those right now). Wondering if I indeed have an updated console? Could anyone confirm again how to check if it is updated? After calibrating according to service manual instructions I feel like I’m pedaling through molasses. Going to recalibrate with lars instructions above. It would be great if Nautalis used this feedba
ackto provide more detailed instructions for calibration.
Just a quick, very non-scientific statement here - I got a Schwinn IC4 in November, and I just had a feeling it was somewhat accurate despite problems other people have had. I just got a Stages power meter crank for my outdoor bike, and based on my perceived exertion and looking at wattage readings of the Schwinn and Stages crank, I’m very confident the Schwinn is accurate. Maybe the Schwinn’s sold in November have been calibrated appropriately, as compared to older ones. If it’s possible for me to put the power crank on my Schwinn, I’ll try it someday and post here. But I’d say it’s possible for the Schwinn to be accurate, for anyone thinking about returning theirs or not buying one, but maybe they’re all calibrated differently. I’d say the handlebars are the biggest downfall of the Schwinn. If you could add drop bars, that would help a lot for comfort and better sprint power.
That is a very bold statement to make. I doubt that it is possible to determine a 10% difference by feel. The only way to know is to have a power meter measuring and then comparing data.
I agree, and I don’t mean to make any definitive statements. Like I said, it’s a very non-scientific comment. I’ve seen people saying they have major problems with Schwinin, maybe like 50% off what the actual power reading should be. I’m sure the Schwinn isn’t going to be ± 1% accurate like power meters, but I think for some people looking for a cheap alternative to an indoor trainer, it’s worth looking into purchasing.
1 Like
The Stages power meter crank I got is specific to my Shimano GRX crank. I’ll have to find out from them if I were to attach it to my Schwinn, whether it would give accurate readings or not. I’m curious about calibrating my Schwinn correctly, so someday I’ll test it, if possible, and follow up here.
I agree it is very frustrating. I called Nautilus and they told me they are aware of the problem and are working on a solution (that was back in December… I’m not holding my breath).
I think the basic problem is that they are distributing these bikes each with slightly different flywheel tensions. Since the wattage output is simply an algorithm of resistance x cadence, it creates a problem, as it will be easier for some folks to hit a high cadence at high resistance (ie: high wattage) when their flywheel is looser than for others.
I was truly surprised to see how accurate the bike was (in comparison to my power meter pedals) once I calibrated it using the approach I described above. I recommend that people take the time to recalibrate it along these lines. If nothing changes, you’ll at least have the peace of mind that your bike & numbers from before were accurate!
Hi lars, thanks again for this post. After recalibration according to your method I was feeling like all of my resistance settings we’re actually a bit easier but after a few rides and an ftp test I think it’s just about where I was before the calibration. I also lodged my complaint with nautilus. It’s clearly a common issue. The mystery is, why isn’t anyone offering to do custom calibration if the company wont do it? I’m feeling like putting out a call for assioma pedals just to borrow from friends to ensure the resistance s correct.
Hi, Hope somebody will help to understand how my IC8 is supposed to work. I read all discussions about recalibration, but as beginner, I do not know if my connection is working well. To make it simple, I do not have automatic resistance change on my IC8. Is it normal? do I have to change it manually when the % is increasing? Everything seems ok (power and speed are synchronized) but I was expecting to have an automatic adjustment of the resistance. Thanks in advance to help me to understand
No the IC8 is a spinning bike with a power estimation. It does not have the option to control resistance.
You will use the resistance same as changing gears. If you want to go faster add more resistance.
Thank you Gerrie, Based on your experience, which resistance (0-100) are you using for 5% of elevation?
You can use any resistance it depends how fast you want to go up and what cadence you want to hold.
Thank you Gerrie, I will try to find my own values, currently I use 24 when is flat, and turn to 32 when % is arround 4-5% (i’m just a beginner 
)
Hello everybody,
I read with great attention all your post since Apr ‘20 about IC8 because I own one since about 1 month. I completely understand that a spin bike is not bycicle simulator, but rather a robust compromise that can cover different needs in a family.
Reading the posts, at the beginning I was disappointed, then a little bit less by going on and comparing with the results I have.
In another forum around here I saw a table speed vs. power (ex. 35kmh at around 220w, etc.) which is what I have on my IC8. So far so good then!
The problem is the FTP value I had, which appears to be in contradiction according to what I saw in this forum. The thing is, never been a cyclist, did not have a clue about FTP before. In principle of course I know now, because I am a runner, I know VO2max…and I am going to re-measure my VO2max which was around 60 a few years ago. Here my question. I normally run during trainings 10km in 42’ with my best repeated twice last year is around 40’…I am accustomed with high intensity intervals as well…so I would expect a fair FTP but I obtained a 360w that seems too much according to your posts… unlike (I repeat) the speeds vs power tables seem correct. Any thoughts?
Thanks
Luca
Here is a power output chart which shows the readings from my Assioma Duo power meter pedals, using various resistance levels and RPMs on the Nautilus bike. Hopefully this will help you figure out whether your own bike is currently giving an accurate output, and whether calibrating may help.
Resistance: 15
60rpm: 70w
80rpm: 115w
100rpm: 170w
Resistance: 25
60rpm: 115w
80rpm: 185w
100rpm: 270w
Resistance: 35
60rpm: 160w
80rpm: 260w
100rpm: 360w
Resistance: 45
60rpm: 200w
80rpm: 325w
100rpm: 450w
Resistance: 55
60rpm: 230w
80rpm: 375w
100rpm: 530w
Resistance: 65
60rpm: 265w
80rpm: 445w
100rpm: 615w
Resistance: 75
60rpm: 307w
70rpm: 400w
80rpm: 485w
Resistance 85
60rpm: 360w
70rpm: 460w
80rpm: 563w
5 Likes
Awesome job, Lars! Could indeed be very helpful for all these lost Nautilus souls :-). I only use my power meter pedals on the IC8 - I don’t trust Schwinn anymore.
Thanks for posting this, Lars! I ran my own test on my Schwinn IC4 after calibrating it using the Nautilus-provided instructions, and I get reasonably close to your power meter readings - though there are still some notable differences. I am not intending to race in Zwift, but still want to know I’m close to “accurate” in my readings.
Here is what I get using the bike’s output to the Zwift app, riding the short FTP workout with ERG mode on, Tempus Fugit route at 0% incline (which shouldn’t matter in ERG mode but just in case… ) -
Resistance: 15
60rpm: 79w
80rpm: 123w
100rpm: 182w
Resistance: 25
60rpm: 121w
80rpm: 194w
100rpm: 280w
Resistance: 35
60rpm: 161w
80rpm: 258w
100rpm: 357w
Resistance: 45
60rpm: 194w
80rpm: 310w
100rpm: 440w
Resistance: 55
60rpm: 236w
80rpm: 381w
100rpm: 536w
Curious to see that my output is higher at low resistance, but is in line or even slightly lower than yours in the 35-45 resistance zone, and slightly higher again at 55. I could probably get a bit closer at the low end if I recalibrated and moved my “zero” to a higher setting, but it would still be trial and error. If we weren’t limited in the number of calibrations we can do, I’d play with it more. For my purposes, this is good enough for now.
Thanks again!
You can duel record and process the data in Zwiftpower, that should give a better picture.