Relative binding energies for C N −2 +C 2 have been determined for fullerene ions in the range 46 ≤ N ≤ 102. The values were derived from metastable fractions observed in a time-of-flight reflectron mass spectrometer. The timescale of the experiments was such that radiative cooling of the fullerene ions did not play an important role thus simplifying the data analysis. The results are compared with previous values of relative dissociation energies for C 2 loss given in the literature. It was found that the relative C 2 dissociation energies for large fullerenes ( N > 60) are significantly higher than previously estimated.