There's only a few miles on these and I trust they'll last a long time, but I felt compelled to write in with only one criticism so far. There is a noticeable low loud grumbling sound between 61-70 mph exactly. I can't explain it but it's there. Other than this, stability, comfort, traction, and noise level is superb. Really though, why would the noise be so loud in the 60's mph range and so quiet on either side of it?