Carbon in direct contact with a hot radiator might no be happy but I had two (one steel, one alu with crabon forks) on a vertical stand right next to a large double radiator with no issues.
Thanks. I can put the metal ones nearest to the radiator and have the crabon a bit further away. I just wasn't sure about how paint/bearings/bar tape would feel about living near a heat source.
Is storing a bicycle near a radiator something I should avoid?