It is not about generic faith in marketing. Experience teaches me some companies tell the truth, some don't. I haven't had a problem with Giant and have no evidence their numbers aren't accurate. Why would I jump to the that conclusion like you did just because you don't want to believe that the ISP frame is lighter? I don't have that inducement to trash Giant's veracity like you do. You're the one taking the negative stance. So it is up to you to go prove the published numbers aren't correct. Surely there is a Giant dealer near you where you can weigh a frame. Or maybe other forum members have experience with this. What say you guys? Any medium TCR Advanced SLs out there with ISP that have verified weights? With or without topper? How about non-ISP versions from certain years they were offered? I am absolutely willing to correct my belief based on evidence. Is there any to be had?