Any such thing? I purchased (ages ago) a used 52mm TB off a forum member and was just getting around to the install. Just for sh!its and giggles, I took out the calipers and measured the TB holes and each is just at about 50.5mm. My calipers were calibrated fairly recently, so I do not believe that's the problem. Even if they were off, they wouldn't be off 1.5mm (roughly 60 thousandths). Hmmmmmmm.