I put some clearshield over the BB and downtube for protection. Sure enough, on my first ride (a race), I was descending a cobbley loose hill at 25 mph and had multiple rocks smack the downtube. The cracks were loud enough that I was terrified to see the result after cleaning the mud off. Not a mark. Just some scuffs in the clearshield. I know my Yeti's scandium tubes would have been dinged as they have a million times before.shortpull said:rocdog, i'm sure there will be more than a few carbon blur xc's and lt's being raced at downieville this weekend. it'll be interesting to hear if the carbon bikes can take the hits once the rocks start flying.