seat clamp help Home › Forum › Bike Forum › seat clamp help Viewing 3 posts - 1 through 3 (of 3 total) seat clamp help crush83Member Hay guys I have a old Marin Palisades Trail that I am turning into a SS comuter. It has a cracked seat tube from the opening about 1cm down. I am not welding it and this is not a solution. The frame has a built in seat clamp that I have had ground off. It has a 30.0 seat post. I bought a 30.0 non qr seat clamp but it doesn’t fit the seat tube. What size will I need? 30.8? Posted 4 years ago cynic-alMember likely 31.8 for steel, or 34.9 for alloy. Posted 4 years ago crush83Member It’s alloy so will order a 34.9 Posted 4 years ago Viewing 3 posts - 1 through 3 (of 3 total) The topic ‘seat clamp help’ is closed to new replies.