price may vary in storeThe new Shimano 105 BR-5800 Brake Calipers see an increase in braking power and added tire clearance at a price that is difficult to beat. Most noticeable update is the redesign of the pivot system that has been a Shimano staple. Instead of using the mounting bolt as the second pivot, creating asymmetrical arms, the new dual-pivot system uses a mounted plate with a centre bolt for frame attachment. The brake arms are cantered over the wheel with an integrated pivot. The cable stop is located to one side, but the new pivot system means that equal pressure is applied when the lever is pulled. This increases your stopping power of 10% from its predecessor, the previous 5700 version. Furthermore, the new design means added tire clearance, which enables you to run up to 28mm tires. This is a rear brake only. Not compatible for use on the front of the bike.