I am trying to get my old ripper going for my son. I had a xcaliber seat post clamp but it is now cracked. I remember something about having to use certain clamps because of the aluminum frame. Can anyone advise my of what clamp I can use and if I need to use a certain seat post? Also if you can advise my were I can purchase these. Thanks for any help.

Welcome to the Jungle another member that knows will be with you shortly.

Xcaliber seat clamps work fine on PKs, the material doesnt matter. You can find another xcaliber on eBay pretty easy I would guess. I think using a chromoly seat post was prefered when using an aluminum frame so it wouldnt seize and freeze stuck in the frame.

Thank you for the reply. A few more questions. I don't necessarily need an xcaliber clamp. I followed a link from this site to J&R and looked at the current clamps. Would any of those clamps be ok on the ripper frame? What type can be used and what type can't. Can I use the quick release? and as far as measuring the for the post, do I measure the inside or outside of the frame? Or do you know what size clamp and post I would need. Sorry for all the questions but i want to make sure that the bike will also be safe for my son. I don't remember all the different sizes when I was putting the bike together so many years ago, the bike shop I bought the pieces from must have made sure that the parts would fit correctly for me. Again thank you for your time.

The newschool clamps won't work. The diameter is too big. The inner diameter of your seat tube is 13/16". Outside diameter is approx 1". The newschool stuff is bigger diameter. You can use a chromoly (best choice) seatpost or an aluminum seat post (use antisieze). The thing you don't wanna do is use a fiberglass post (Uni seat). They flex and cause cracking issues at the top of the seat mast. Any oldschool clamp, hinged or not, will work fine. These are ALL OVER Ebay. Just search BMX or OLD SCHOOL BMX.