The Mavic EN521 rims are strong rims that will not weigh you down helping to make these durable rims a great choice for Enduro or light Freeride builds. These rims feature Mavic's SUP techonolgy which helps to increase wheel strength and helps to eliminate wheel shudder while braking. 6106 aluminum alloy Clincher Disc only Single eyelet Traditional drilling ETRTO compatible size: 559 x 21c Recommended nipple length: 12 mm Recommended rim tape: 559 x 20 x 0.6 Recommended tire widths: 2.10 to 2.50 SUP Technology Weight: 540g