I thought eKretz's test with the WheelCheck utility was interesting and should show some results of a wheel that is being neutered by the firmware. That is, if the test is really to be a measure of wheel strength/speed.
So... I ran some tests with my T500RS in a similar manner, though I used the GT rim as it's heavier and should show the issue more readily, I'd hope. I had previously done this a few times and noticed that the results seemed to vary a little, in fact enough that it might be hard to determine if the issue was heat or something else. I decided to run 3 tests when cold. (wheel freshly turned on after sitting all day in 64 degree house with nobody in it) I would then check the results and average if necessary.
I then ran a '64 Shelby Cobra 289 around Bathurst using the HistorX rFactor mod. I ran on max FFB for well over an hour straight, having a blast mind you.
Fan on the wheel was in overdrive. You could feel that the motor was pretty toasty, (by no means "hot") though I didn't measure it, sorry... Maybe next time.
I then ran the test again, 3 times in a row, same story as above... I noticed no change beyond the standard deviation that showed between successive tests. I placed all 6 runs on the same graph together and it's hard to distinguish what is what, they are that close. The only "interesting" thing of note was that it seemed the wheel's "finishing point" is always closer to max when warmed up, than when cold. I'm guessing this is from the belts, etc. loosening up which allows the wheel to "coast" better.
So, I don't know if maybe it's not a good test (seems like it should be relevant on some level...) or the T500RS isn't cutting the power to it's motor. I have some weights (weight lifting weights) I could strap on the rim, maybe a 5 pounder or something... That'd certainly make a huge difference LOL! I'd rather not though.
That said. I have a much simpler way for me to test this, since I don't have one of those scales and it will tell me exactly what I want to know... If I find the time, I will just connect my oscilloscope to the motor terminals. The motor is no doubt driven by PWM as are the Fanatec wheels. The duty cycle of the PWM determines the current sent through the motor. If even at a cold state the T500RS motor is not running at a duty cycle of 100%, the motor is not being fully utilized. As well, I can easily measure the duty cycle to determine the exact percent of decrease, if any, when it's heated up.
Anyhow, I just wanted to add that in there because I thought it was interesting. I can post the graphs at some point but they aren't all that interesting to look at since like I said there's not any discernible deviation between "hot" and cold conditions. (on the graphs)
Lastly, it is interesting to note that on all of the graphs, the distance the wheel travels from "low peak" to "high peak" is nearly the same, despite the temperature of the motor and any other variations. What I mean is, maybe on one graph it goes down to 5000 on the first part of the cycle, then up to 2500 on the next part. Then on another run it goes down to 5200 on the first part of the cycle, it will go up to 2700 on the next part. Always showing an approximate change that matches, no matter the motor state.
That's about all I'm going to do on this for now. I mostly did this because I was curious if my wheel gets weaker, as I had not noticed it getting weaker... If it does, so far I can't really tell. I don't want to concentrate on it either because things like this have a way of making you perceive something as happening that may not be. At some point, I'll check the PWM stuff I was talking about. I apologize but I'm not going to purchase a digital scale for this purpose, even at $10-$15. It's just not that important to me.