Shimano SM-RT64 Centerlock MTB brake disc with locking ring (internal groove)

A reliable Deore Shimano disc for powerful and consistent braking

The Shimano SM-RT64 is a Centre Lock brake disc designed primarily for mountain biking and intended for cyclists seeking effective, consistent and reliable braking. It combines a stainless steel rotor with an aluminium star, featuring a Centre Lock mounting system that allows for quick installation and removal on a compatible hub.

This version comes with an internally serrated locking ring, also known as Internal Serration. It is particularly suitable for set-ups fitted with a quick-release mechanism or a 12 mm thru-axle. For 15 mm or 20 mm thru-axles, Shimano offers a suitable adapter ring such as the SM-HB20.

The SM-RT64 is available in several diameters, including 140, 160, 180, 203 and 220 mm, depending on the version. The choice of diameter should be based on the specifications of the frame, fork and brake caliper.

Key features of the Shimano SM-RT64

• Centre Lock brake disc.
• Internal-grooved locking ring supplied.
• Rotor Made of stainless steel.
• Aluminium centre star.
• Two-piece construction.
• Compatible with organic and metal brake pads.
• Designed primarily for mountain biking.
• Available in several diameters.
• Quick fit and removal thanks to the Centre Lock system.
• Excellent balance between performance, reliability and price.

Centre Lock technology: a practical fitting system

The Center Lock system Shimano secures the disc directly to the hub’s splines. A locking ring then holds the assembly in place.

Compared to a traditional six-screw fitting system, this system makes fitting and removal easier and ensures precise positioning of the disc. Shimano also states that this design helps to achieve a rigid connection between the rotor and the hub.

The internally grooved ring is distinguished by its clamping system located inside the ring. It is particularly suited to hubs compatible with this type of lockring.

A rotor compatible with both resin and metal brake pads

The SM-RT64 is compatible with both resin and metal brake pads. This versatility allows the braking behaviour to be adapted to the cyclist’s needs and riding style.

Metal pads may be particularly suitable for more demanding mountain biking, whilst organic pads generally offer quieter and more progressive braking.

However, it is important to check that the disc, pads and caliper fitted to the bike are fully compatible.

Which diameter should you choose?

The SM-RT64 is available in several diameters. Shimano lists the following sizes in particular: 140, 160, 180, 203 and 220 mm.

• 140 mm: best suited to set-ups requiring lightness and moderate power.
• 160 mm: an excellent compromise for many mountain biking applications.
• 180 mm: offers greater stopping power and heat dissipation.
• 203 mm: suitable for activities requiring greater braking power.
• 220 mm: designed for compatible set-ups requiring even more power; Shimano states that it offers approximately 10 per cent more power than a 203 mm disc.

Please note: you must never increase the diameter of a disc without checking compatibility with the fork, frame, caliper and adapter.

A simple and robust design

The SM-RT64 features a construction comprising a stainless steel rotor and an aluminium star. This two-part design maintains good rigidity whilst keeping the disc’s weight under control.

Its relatively simple design makes it a particularly attractive option for the maintenance or refurbishment of a mountain bike fitted with a Centre Lock system.