Just thought I would pass this info along. I cracked my Twinwalls a few days ago in a low speed crash (15 MPH or so). The crack started near the cross bar and was around 1" long. The opposite side also showed stress lines. I emailed Alan Curtin (Renthal LTD) and he replied to me stating to just send them in and they would replace them FOC. Not wanting to pay the shipping (and making my $130 bars now cost me $140) I went into my dealer (Capitol Yamaha). I learned at my dealer that Renthal is no longer honoring the "guarenteed for life" pitch that they used to sell me the $130.00 bars. I showed them the email and they contacted Parts Unlimited and approved the return (thx Alan). I got a credit from the dealer and bought some Tapers.