I always mess wheels up!
What i have found is that some cheap wheels i have fired get stuck and don't spin where the large quality ones like 'Fiery Eye' Don't get stuck as much. Atleast thats what ive found - was quite worried about the wheel in the coral cube box when i fired it as it was the only one in the box but it worked well.
All 15 wheels that i fired last night gone really well and they was all cheap ones... I nailed 10 wheels to a piece of chipboard with only about 4 inches space inbetween the wheels. Suprisingly enough the wheels lite each other but started going boom. lol, it was really impressive but reminder for myself leave more space inbetween next time