actually, GT, mongoose and supercross made CF bikes in the mid 1990's, good luck finding any info on them though. i remember when BMX plus! tested the supercross frame it broke because it wasn't full CF. they used CF tubes bonded to steel "lugs" like on a giant cadex carbon frame. anyway, it didn't really technically break, it just kind of, pulled apart in mid-air because they decided to use some stupid bolts that pierced the CF, and also there was residue on the steel part that was inserted into the CF part.

the mongoose frame was an injection molded one that actually did fairly well in races and such, i forget who their top pro was at the time, brian somebody (not foster). it was a pretty good frame. it was called the stealth.

the GT carbon fiber was a CF/aluminum frame. the front triangle was injection molded CF and was bonded to an aluminum rear triangle. the chainstay/bottom bracket joint looked like old auburns. i think some guy they used to call the lumberjack, i think his first name was either gary or greg, rode it in races and stuff. it held up pretty well too.

anyway, i remember seeing the supercross frames (after they refined them) at a local shop and kinda laughing about how they just fell apart. and i'm pretty sure the mongoose made it into production too. it sold for around $500.

i can't find anything about CF BMX frames either, just a brief blurb here or there about the stealth on google.

i think everyone stopped making them because they cost too much, not because they broke.