more nuanced answer: xc racing: i'd prefer tapered (not simply oversized) headtube and 9mm for weight savings with improved stiffness/vibration damping. trail riding: 15mm thru axle as this is where stiffness counts most, per my experience, especially on 29ers (which i ride).
best answer (for me): both! i have a superfly 100 (tapered headtube) and converted my f29 to 15mm with new lowers. despite the mild weight increase, the performance gain is totally worth the grams!
best answer (for me): both! i have a superfly 100 (tapered headtube) and converted my f29 to 15mm with new lowers. despite the mild weight increase, the performance gain is totally worth the grams!
