Now that I created another vehicle with these wheels (first was back in Sep. 2014) I saw that due to Keens improvements/changes the wheel parameters seem not to be good for your wheels anymore.
The wheels seem to have a more aggressive sideways friction due to these changes so that vehicles tend to flip when going sideways.

Also I detected a bug:
When the wheel is turned back (like the front inner wheel) blocks in front of the wheel may be damaged/destroyed. Unexpectedly, since actually the wheel is moving away from the block. Looks like an issue with the hitbox maybe extending too much to the inside or so combined with the violent wheel movements which can occur in certain situations (mainly when unloaded).

This bug is also occuring with vanilla wheels but not as often.