Purpose <p>Pacing is a key determinant of endurance performance, yet pacing behavior in mass-participation Gran Fondo cycling events remains insufficiently described. The objective of this study was to examine pacing differences across performance-based finishing-time groups in the Quebrantahuesos Gran Fondo.</p> Methods <p>Publicly available split-time data from the Quebrantahuesos 2025 edition were collected via web scraping and 6589 finishers were included. Pacing metrics included pacing range, split-level relative speed, and the percentage of total race time spent in each segment. Differences between performance groups were tested, and k-means clustering was applied using relative speed, time distribution, and pacing range to identify pacing-derived groups.</p> Results <p>Pacing variability differed significantly across performance levels (<i>p</i> &lt; 0.001), with the fastest cyclists (&lt; 6:00&#xa0;h), demonstrating the lowest pacing range compared with all other groups. Faster cyclists adopted a more conservative start and became progressively more differentiated from slower cyclists in later race segments, particularly at the finish. Time distribution patterns indicated that faster cyclists spent proportionally less time in decisive mid-race climbs and showed the greatest separation in the final segment. Clustering revealed three distinct pacing profiles: the best-performing cluster was characterized by lower relative speed early in the race and superior performance during the major climbs, whereas the highest-variability cluster exhibited slower mid-race speeds and greater time accumulation in the final segment, suggesting suboptimal effort distribution or premature fatigue.</p> Conclusion <p>Quebrantahuesos performance was associated with lower pacing variability and segment-specific strategies, supporting individualized pacing recommendations for recreational cyclists and coaches.</p>