Nice Update, Matt. Thanks for posting.
No reaction from my support contact so far (except … “everything ok”) … 
If Andy’s readings are well below 300 watts constantly I think we can safely assume it worked … (see my posting above). @andykingster: Would help to post your new watt readings on different resistance levels (I used 35/45, 60rpm)
I received mine last week. I get around 250-270 watts when going 23-25 mph. Heart rate close to 150. I don’t know how accurate this is. It seems like I pass people a little too easily. Although I am pushing pretty hard.
I’ve had my IC4 about a week and have a Wahoo Kickr Core to compare with. Noticed right away the IC4 was way off. Last night I did the FTP ramp test on Zwift first with the Kickr Core which i got an FTP of 183, then about 10 minutes later with the IC4 which I got 390! I’ve tried Schwinn support and they said it was a Zwift problem. I’ll also try this calibration tonight. I really hope there is a fix cause I like the bike and have been shopping for some power meter pedals just so I can use Zwift. As it is, I can’t even use Zwift as I can enter any 4-5 w/kg race and easily stay in first place when I should be down around 2 w/kg.
Can you try looking at the calories burned on your console and covert that to watts which is reported in Zwift? Then you can see if the console is the issue or Zwift is the issue.
energy (kcal) = avg power (W) X duration (hours) X 3.6
http://mccraw.co.uk/powertap-meter-convert-watts-calories-burned/
Ok I just did a quick run through. My calories reported on the Schwinn console were close enough to those reported in Zwift. Also the equation between calories and watts seemed to hold up fairly closely. I think that proves that Zwift isn’t the issue and that the calorie(power) output of the Schwinn is incorrect. I also think that the link between the bike and Zwift is done through the console power meter. I only tried one resistance level so maybe things vary more at different resistance levels…
Hi there, I did the following test this evening:
As far as I understand the calibration process this position of the resistacne knob is where the 1% value (=resistance level 1) should start:
In my (presumably mis-calibrated bike) after reaching this position, I can still turn the resistance knob 400 degrees (!) clock-wise until the training computer shows resistance level 1!
So, basically, what my bike considers “1” is a much higher resistance level! (a level that is reached 400 degrees later!). You can try it for yourself - 400 degrees is around 12-15 resistance levels on my bike.
So all speed and power output on resistance level 35, for example, are actually speed and power output on resistance level 20-25.
This would explain that on lower levels (~30), training computer/Zwift is showing measurements that are much too high (level 30 is actually just 15-20). On higher levels, the miscalculation decreases percentage-wise (resistance level 60 is actually 45-50 …).
Makes perfect sense for me, just didnt do the actual calibration since support didnt suggest it to me so far.
Hi Bernhard, what you seem to be saying is the console is reporting a lower resistance value than is physically set. In that scenario the power would be under reported and not over reported.
How do I know if the console is in power up mode?
Yes, that would me. Started a month ago. FTP 211. 
Hi, this is not in my IC8 manual, can i ask where you got this information? I have the same problem, it’s too easy to overtake other cyclists and not working hard.
I spoke with a Schwinn customer service rep yesterday and let him know my power output was at least 2x more than what is should be. He put me on hold and talked with one of their engineers. He said the engineer stopped him before he was done explaining the problem and said I know exactly what is going on (due to many people reporting this problem). He said the bike is reporting the correct data to Zwift but the Zwift software is not interpreting it correctly. My reply was “If Schwinn is selling this bike as designed to work with Zwift, shouldn’t they make sure Zwift tests the bike out and makes sure it is compatible?” He did give me the option to return the bike as I explained to him I purchased this bike primarily to use with Zwift and when I can win any race I enter it is obviously not working correctly with Zwift. So I’m thinking replacing or re-calibrating the sensor won’t do anything, the only solution that is going to fix this is if Zwift tests the bike out and makes whatever adjustments are needed.
Great info David, thanks!
I guess it still doesn’t explain why the calorie output on the actual schwinn console(which also matches the calories on zwift) is off by a factor of 2.
Hi there,
I wanted to buy this bike to use it with Zwift but now reading all this…
Does anyone know other indoor bikes (which are available in Germany and do not cost 2500 EUR 
which are also compatible with Zwift and show the right numbers?
Thanks
Buy a used Road bike and an Elite Zumo, Direto (X), Kickr Core, o.ä.
Much cheaper, much better and you have a bike for riding outdoor in the summer
Sounds Good - I will Look into it. But is there really no indoor bike in a similar price range as the Schwinn IC8 compatible with Zwift?
DC Rainmaker said in one of his Videos, the Wattbike Atom is the cheapest Smartbike.
But a used bike and a good Smart Trainer is still much cheaper and way more versatile.
Hi Andy,
I just interpreted power up mode to be “on.” So plugged in and moved a crank to get it to power on.
Hi Chris, thanks for thinking it through. I think you are right. Telling the bike by recalibrating it that “1” is 400 degress “earlier” (counter clock wise) might probably cause the measurements to go even higher compared to now.
Well, there goes my theory …
On the other hand - we won’t know for sure recalibration doesnt change it for the better until someone can post his/her results … recalibration does actually change not only lower limit (i.e. 1%) but also upper limit (i.e.100%) …and we do not know the power curve …
Hi David, thanks for your update - I would expect that an engineer from Nautilus / Schwinn might tell us that Zwift is the reason … I could even tend to believe the explanation, however:
What puzzles me is, that not only the Zwift watt output is looking quite high - the measurements of the training computer look similarily inflated … just try to ride with low rpms (e.g. 30) on lower resistance levels (e.g. 30) and see what happens with speed, calories and distance … compared to your effort level.
Hi Bernhard,
I agree that a recalibration will change things but based on how my own bike is set I think the difference people will see is quite minimal. I’m also hesitant to re-program something and have the warranty voided, though I think the risk that Schwinn would care is very low.
I only did the free 25Km on Zwift but if you have time and want to try a “virtual” calibration then I would suggest the following.
Do a normal hard workout on a constant resistance, let’s say on level 40 and keep a constant rpm. Doesn’t have to be long, maybe 5-10 minutes. Record your average watts and rpm.
Lower the resistance to level 1 and go the same rpm for the same time as you did in part 1. Record your watts and verify average rpm is close enough to part 1.
Now which watt level is close to what you would expect for your part 1 workout? If the watts shown in part 2 is closer to what you would expect then you would have to calibrate the bike such that 40 is now equal to 1.