Having ridden mountain bikes primarily for the last 16 years I have had the best of luck with the Campagnolo Thor rims. They seem like they were indestructible and this was racing them in NORBA NCS Downhill races in '94-'96 before the long travel bikes with big rims. I remember at Mount Snow taking hits that I that were going to collaps the wheels. I still have one front wheel that is true, but the rim is worn so thin I don't dare ride it any longer. At the present time I have three sets of road wheels with Campagnolo rims and the are running straight and true despite bunny hopping road kill on these West Virginia roads.