i am going to have a frame and fork chromed, and is there anything i should do to prep the frame first. how do i remove the old chrome? do i need to?
Johnny

johnny, find a shop that can/will do it. visit them and check out finished product. communication is the key, see,show, tell them what you want ,expect. let the platers do the hard stuff....

Johnny,
Chrome is best removed by your plating shop and not mechanically (grinding/sanding). I would make sure that if there are any problem areas -like deep pits- that the plater be made to aware that you are willing to pay extra to have them built up with copper or whatever it takes to "rebuild" the surface. Otherwise you will get shinny pits back

In extreme cases the plater may inform you that welding may be necessary to restore the surface to a condition that CAN be plated. Also, ask the plater to be on the lookout for previous repairs if you suspect your frame may have been replated before.
Sometimes after the old chrome is removed a bad repair can be exposed that may require drastic procedures to correct (let's hope not)...for example I've seen primitive lead/solder crack repairs under chrome.

You have to approach chroming as a much less forgiving finish method than painting...be brutally honest with yourself BRO...if your frame is schizen it's often better to get a better one or paint it. Not trying to bum you out only trying to minimize your possibility of disappointment later on (I'm big on expectation management). Most platers think they can plate anything, no matter how bad it is, to the point of bankrupting your kids' college fund. Try to pick a plater that someone you know locally has used with good results. And for Christ sake don't take your cool BMX frame to some hack that does car bumpers unless you like the look of peeling chrome alongside those Aerospeeds? was it.