Aluminum might be one of the worst metals to use in an application like this. https://velo.outsideonline.com/road/road-racing/technical-faq-aluminum-frame-cran

Aluminum might be one of the worst metals to use in an application like this. https://velo.outsideonline.com/road/road-racing/technical-faq-aluminum-frame-crankarm-fatigue/ https://velo.outsideonline.com/road/road-racing/technical-fa... >Aluminum does not have a distinct fatigue or endurance limit, so its S-N graph curves down from the upper left to the right and continues to curve down lower and lower toward the lower right corner of the graph. This illustrates that it will eventually fail even from low stress applications, given enough of them. Steel/titanium, if its fatigue tolerance is in the temperature range, would last much longer if not near indefinably until it came to impacts.