Does such a thing exist? I know you can convert hope 24mm press for to gxp but can’t find anything for 30mm
If it does exist I'd say Wheels Manufacturing would probably make it. I converted my BB30 to an external Shimano 24mm with one of theirs.
id sooner buy a gxp BB to suit the frame and benfit from the potentially larger bearings
You need a new BB as opposed to a conerter, but yes
https://www.bike-discount.de/en/praxis-works-bb30/pf30-sram-gxp-mtb-bottom-bracket
Found this one on Google too
https://www.c-bear.com/en/products/bottom-bracket/bb30-sram-gxp
I'd steer clear of converters that sit inside the bearings, GXP works by loading the non drive side bearing in both directions, unless the BB is designed for that then it can cause problems with the bearing drifting out, same on the drive side, SRAM BBs use a circlip, no one else does as the drive side crank usually retains it.
TBH I'd either use one of the screw together conversions to convert the frame to a BSA threaded shell if it creaks, or go with BB30 cranks if it doesn't and sell on whatever you have. Either could end up cheaper than a conversion BB (and probably be more reliable).