This study presents a comprehensive characterization and analysis of the uncatalyzed rTCA cycle using recently developed reaction network exploration methods. The resulting network comprises hundreds of quantum chemically characterized reactions, providing the first complete kinetic description of the uncatalyzed cycle and its side reactions. The results demonstrate that kinetic constraints severely restrict cycle feasibility under prebiotic conditions, despite thermodynamic calculations suggesting the viability of both the primary cycle and parallel alternatives. Several reaction sequences in the uncatalyzed cycle show kinetic preferences matching modern enzymatic pathways, particularly in the ordering of CO2 additions and carbonyl reductions, even though alternative sequences are thermodynamically possible. Nevertheless, kinetically favored sidereactions were identified for five of the main cycle reactions and no kinetically competitive parallel cycles were discovered. Under the simulated conditions, the primitive rTCA cycle is also kinetically inhibited by the relatively stable 2-oxoglutarate intermediate that forms after the first CO2 addition and acts as a local thermodynamic sink. These findings reveal how kinetic factors constrained the emergence of the modern rTCA cycle and highlight several species whose conversion would have to be catalyzed in prebiotic predecessors of the rTCA cycle. These findings are consistent with the idea that early carbon fixation cycles may have relied on other mechanisms to facilitate chemical reactions in a prebiotic environment or in combination with the compartmentalization of certain reactions within the rTCA cycle catalyzed or as shown in several studies that use Zn, Cr, or Fe as potential catalysts.