There are a lot of great carbon mtb wheel options out there. But the 5 year warranty is what keeps me loyal to the ENVE brand. It has be my experience in the past that ENVE holds true to their guarantees and honors their warranty if you are the original owner. MAKE SURE TO REGISTER YOUR WHEELS ON ENVE.COM! I bought the M60/forty series to replace some 50/fities that came on my Scalpel Team. The M60s have a slightly wider internal rim profile (2mm wider than the 50s) and are also a bit more robust which should add a little extra backbone when these are blasting around the local Park City trails.
These carbon wheels ride awesome but like ANY product associated with mountain biking, a bad bounce off a boulder or a poorly chosen line can sign the pink slip to one of these super-tough, super premium wheels.
Do yourself a favor, Register your fresh new wheels and shred with confidence!