Many bikes from new have a bicycle disc that is a low cost item to keep the bike price down and is often marked with the words “Resin Pad only” which means it is normal factory rolled material and is NOT hardened and tempered and can only be used with standard trekking organic pads. Not only are these new EBC replacement bicycle disc products HARDENED AND TEMPERED they are precision ground to be flat and parallel meaning you won’t get distortion, you wont get lever pulsing and won’t get DRAG. If you see a brake disc any lower in price than EBC this is what you are very likely to be getting, a low cost unhardened piece of steel that will warp, wear out fast and drag. Good for your leg muscles and your workout though. On the other hand trust a brand name like EBC and buy this quality product.
