RT series is the serial number of Shimano discs.
They all start with RT. The higher the number, the higher the grade. For example, RT56 is entry-level, equipped with Shimano oil brakes worth 200 to 400 yuan; RT66 is mid-range, standard for professional mid-range oil brakes SLXM7000; RT86 is secondary The top-level professional high-end XT oil brake is standard. (But the size is universal. XT oil brakes can also be equipped with RT56 discs, but RT86 is a "sandwich" technology, Shimano's exclusive patent. Three layers of different steel and aluminum are pressed together to ensure strength and expansion coefficient. and heat dissipation). The above three types are all "6-pin" structure discs (most discs on the market are also 6-pin type, fixed with 6 pins and the hub). . . In addition, Shimano's RT series also has a "center lock" type (developed by Shimano itself, which does not use screws, but uses a locking plate to fix the disc and hub, eliminating the need for the "6-nail" type to twist Different forces may cause the disc to bend and scratch, or even loose screws, causing potential accident problems). The "center-lock" type also starts with RT, but the number is different. For example, the center-lock disc of the same level as RT86 is RT81. See the product description or consult the seller for details. . . Finally, note that due to the large sales volume of Shimano discs, there are many imitations of traditional craft discs other than RT81 and 86 "sandwich" technology, with RT56 being the most common. Imitation ones are prone to deformation (disc scratching), rust, and abnormal brake noise. . . There are no imitations of the center-lock type because of the increased technical difficulty and low sales volume.
Ordinary level RT. RT54, RT56. Genuine products are made of high-quality martensitic steel, which is rust-free and highly wear-resistant. The corners and the inner edges of the round holes are chamfered (to prevent scratches on the edges or damage to the ring), and there are very few polishing marks on the surface. Mirror-like, high brightness. Basically, you can tell the difference by comparing the imitation ones.