Conversely, spirocyclohexyl nitroxides cis,cis-9 and 11 exhibit low Tm dephasing rates even at higher temperatures, with dimethylated spirocyclohexyl nitroxide cis,cis-9 having relaxation rates similar to the non-methylated analogue 11 up to ca. 100 K. Additional dephasing beyond this temperature is presumably driven by rotation of the methyl substituents on the nitroxide ring. The spin echo decay curves at 100 K (Figure ) illustrate how distinct behaviour of different methyl environments have a critical impact on Tm at this temperature, which can be easily achieved using liquid nitrogen cooling. The intriguing consequence of this finding is that not all methyl substituents are created equal. We hypothesize that this diversity in impact on Tm can be explained not only by different rates of methyl rotation, but also by distance from, and alignment with, the anisotropic spin tensor.