This study aimed to compare the performance at World Marathon Majors of three types of racing wheelchair frame materials: Aluminum (Alu), mixed Carbon-Aluminum (CA), and carbon (Carb). Three elite wheelchair athletes (wheelers) (1 male and 2 females) were chosen for the performance analysis, which was conducted on 117 marathons (Alu, n = 49; AC, n = 25; Carb, n = 43). Compared to Alu and CA, Carb was significantly faster (249.18 ± 168.39 s or 4.07%; p = 0.001; Effect size = 0.89) and (388.60 ± 224.06 s or 6.34%; p = 0.0001; Effect size = 0.93), respectively. In addition, no interactions were observed (p > 0.05) between the material of the frame and i) the course profile, ii) the steadiness of intensity, iii) the elevation gained from the start to the finish line, and iv) the surface quality. However, Carb frames behavior in Majors, in which there are remarkable descent sections were 6.9% faster or 412.4 s (effect size = 0.64) relative to Alu, showing an even greater advantage with CA (7.6% or 455.4 s; effect size = 0.63). In conclusion and considering the remarkable advantage in terms of performance that Carb frames confer to elite-wheelers compared to those who use Alu and CA frames, as also the unaffordable price of Carb racing wheelchairs for most elite-wheelers, we advocate for consideration of strict regulations (i.e., do not allow the use of Carb frames at sanctioned marathons) by the government body of this sport IPC Athletics.