wheels I know of considered very glider safe.
freedom wheel, now made by myfreerunner.com NOT atticworz.
raptor wheel, at
www.mygliderwheelsandmore.com/shop-for-wheels.html
custom cruiser.
also apollo at critterlove.com.
I have 6 gliders, have had up to 15. I use freedom wheel, raptor wheel,
a treadmill - unkown maker, and think a custom cruiser.
In 5 years I have NEVER had an accident with a freedom or raptor.
I had a raptor that started to crack on the back lid part, so I took it out
and threw away as I thought the nails could get stuck in the crack while running
on wheel.
with any of these wheels you must clean and INSPECT, if a problem is seen,
throw away or fix immediately.