To investigate the effects of bike fitting compared to qualitative-based riding posture recommendations on comfort, fatigue, and pain in amateur cyclists. This was a randomised controlled parallel trial of 162 amateur cyclists divided into two groups: bike fitting group (BFG) - participants received a bike fitting session based on 3D kinematic assessments; and a control group (QG) - participants who received a handout containing qualitative-based cycling posture recommendations. Primary outcomes were perceived comfort (FEEL Scale), perceived fatigue (OMNI Scale), and perceived pain (numeric rating pain scale, NRPS). Outcomes were assessed at baseline, when the interventions were delivered, and after 15 days. Intention-to-treat analyses were conducted using student -tests between pre and post intervention on both groups. All dependent variables from BFG displayed significant statistical difference between both groups post-intervention ( < 0.05). FEEL Scale and OMNI Scale results showed the highest changes of all variables under analysis (mean differences of 3.12 and 3.95 points, respectively); while the body parts with more reduction in riding pain were Groin and Back (mean differences of 1.68 and 1.35, respectively). In conclusion, 3D kinematic bikefit demonstrated superior improvements over riding pain, comfort and fatigue compared to qualitative riding posture recommendations.