A few months ago I pulled out a sliver of glass from mine. The shard cut deep, but very luckily only into a side knob (softer rubber). I only noticed the intrusion when the trail ended and the road began, and I started hearing the periodic sound of grinding glass on pavement.
However my reply might be irrelevant in that my Tricross came stock with Houffalize.
As for the Houffalize, they're pretty tacky out on the trail (70a center, 60a shoulder) and don't pack in much mud.
Last edited by iam93157; 04-17-11 at 03:02 PM.