Buy the bike …. found a great frame a GT XIZANG LE from late 90’s early 00’s on eBAY with Rolf Propel Wheels and SID fork for a bargain.
It is currently set up as single speed but the idea is to put a rohloff speedhub on the rear of the bike.
Currently the bike weighs 19lbs but this would rise to 23 24ish once setup.
This will be used for mtb marathon races 50km plus where riding on the Klein makes me feel like I have been punched in the kidneys ….. A LOT.