Marcus 'Mac' O'Reilly is a Cytech Master Mechanic and former head wrench for a UCI Continental racing team. He possesses over two decades of workshop experience, specializing in hydraulic systems and carbon frame integrity. Currently, he runs a specialist service center focusing on high-end MTB and road bike maintenance.
Marcus O'Reilly is a veteran of the bicycle industry, known for his uncompromising standards and deep mechanical intuition. Starting his career in local bike shops in the North of England, he rapidly progressed to become a Cytech Master Mechanic, the highest attainable qualification in the UK trade. His career includes three seasons on the European circuit as a race mechanic, where he mastered the art of rapid diagnostics and precision tuning under extreme pressure. Marcus specializes in the complex maintenance of modern bicycles, including full-suspension pivot service, hydraulic brake bleeding, and electronic drivetrain troubleshooting. He is an expert in materials science, capable of identifying dangerous carbon delamination and advising on the nuances of frame repair versus replacement. His technical guides are written for the home mechanic who wants to move beyond basic cleaning to understanding the engineering principles behind their machine. Whether explaining the cavitation of damper oil or the intricacies of press-fit bottom brackets, Marcus provides clear, no-nonsense instructions rooted in years of getting his hands dirty.