The pyrolysis of undiluted cyclohexane has been studied in a continuous flow tubular reactor at temperatures from 913 to 1073 K and inlet feed flow rates in the range 288-304 g.h(-1) at 0.17 MPa reactor pressure with average reactor residence time of 0.5 s calculated based on the pressure in the reactor, the temperature profile along the reactor, and the molar flow rate along the reactor estimated by the logarithmic average of the inlet and outlet molar flows. The reactions lead to conversions between 2% and 95%. Forty-nine products were identified and quantified using two-dimensional gas chromatography equipped with thermal conductivity and flame ionization detectors. The products with molecular weights between those of hydrogen and naphthalene constitute more than 99 mass % of the total products. A kinetic mechanism composed exclusively of elementary step reactions with high pressure limit rate coefficients has been generated with the automatic network generation tool "Genesys". The kinetic parameters for the reactions originate either directly from high level ab initio calculations or from reported group additive values which were derived from ab initio calculations. The Genesys model performs well when compared to five models available in the literature, and its predictions agree well with the experimental data for 15 products without any adjustments of the kinetic parameters. Reaction path analysis shows that cyclohexane consumption is initiated by the unimolecular isomerization to 1-hexene but is overall dominated by hydrogen abstraction reactions by hydrogen atoms and methyl radicals. Dominant pathways to major products predicted with the new model are discussed and compared to other well performing models in the literature.