Topeak defender m1xc11 mudguard setdefender m1 is compatible with all standard front forks including reverse arch designs the unique quick release attachment system integrates the defender m1 seamlessly with the front of your bike the xc11 is a lightweight removable rear fender providing exceptional mudspray protection and built specifically for 27 5 650b mountain bikes multiple pivots allow easy fender angle adjustment for a perfect fit while the quick release clamp adjusts to fit 25