My radwagon 4 came with mechanical disk brakes and they stopped the bike but it always felt like a bit of an adventure when going down a hill with a stop at the bottom. Checked factory brake pads and didn't seem any reason to switch to a different pad due to wear. Ended up buying these hydraulic calipers. Very easy switch out to the new calipers, way less than an hour of work. Perfect fit, didn't use any of the associated extra parts that came with new calipers, reused old bolts and washers. Made a tremendous difference in feel and confidence in actually stopping. Well worth the time, effort and money.