Shimano SM-RT56 6-Bolt Disc Brake Rotor
$70.00
Color Options
SilverSize Options
A 6-bolt rotor for resin pads only. The Shimano SM-RT56 comes in 160 mm and 180 mm, mounts with six bolts on a 44 mm PCD, and includes anti-loosen tightening plates. The braking face is etched RESIN PAD ONLY. Metal pads wear this rotor quickly, so check the pad compound before you fit it.
At a glance
- Type: 6-bolt disc rotor, not Center Lock
- Brand: Shimano. The rotor face is etched MALAYSIA
- Model: SM-RT56. 160 mm part ESMRT56SC, 180 mm part ESMRT56MC
- Diameters: 160 mm and 180 mm on this page
- Pads: resin (organic) only. Both narrow and wide pad shapes are listed as compatible
- Mount: 6-bolt, P.C.D. 44 mm, with anti-loosen tightening plates
- Minimum thickness 1.5 mm and a rotation arrow are etched on the rotor
When this rotor is the right replacement
Replace a rotor that is below its minimum thickness, warped, or deeply grooved. Braking then feels soft, noisy, or uneven. The SM-RT56 is a one-piece stainless rotor for riders who already use resin pads. It is not an upgrade path onto metal pads.
Long descents in Hong Kong heat will warm any rotor. This one has no floating carrier. If you ride loaded descents and need metal pads, choose a rotor Shimano lists for metal-pad calipers.
Who it suits
- Bikes with a 6-bolt hub and resin pads: mountain, city, or disc-brake road
- Riders choosing 160 mm or 180 mm on one page
- Not for Center Lock hubs (unless you add an adapter), metal pads, or frames and forks that do not allow that diameter
We already sell the resin-only Shimano SM-RT26 160 mm 6-bolt rotor and Shimano SM-RT26 180 mm 6-bolt rotor. Neither accepts metal pads. The SM-RT56 specification specifically includes anti-loosen tightening plates.
Resin pads only
The pad is the block inside the caliper that grips the rotor. Shimano resin pads come in a narrow face and a wide face, depending on the caliper. The official table marks both as compatible. The limit is the compound, not how wide the pad is. "Organic" and "resin" mean the same thing here, matching the RESIN PAD ONLY etching.
Do not fit metal or sintered pads. Shimano's compatibility note says resin-only rotors in this group are easily damaged by metal pads.
160 mm or 180 mm
Same model, two diameters. The 160 mm rotor is etched φ160 and carries part number ESMRT56SC. The 180 mm rotor is etched φ180 and carries ESMRT56MC. The current Shimano page lists only these two diameters, not 140 mm or 203 mm.
Stay within the maximum rotor size marked for your frame and fork. An 180 mm rotor often needs an adapter, depending on the mount you already have. If you are unsure, send photos before ordering.
Contact us before ordering. Use the shop enquiry page or the Jollymap Facebook page. Tell us whether the hub is 6-bolt or Center Lock, the rotor diameter fitted now, and the maximum size your fork or frame allows.
Compared with other rotors
| SM-RT56 (this page) | SM-RT26 (already on the shop) | SM-RT66 | |
|---|---|---|---|
| Mount | 6-bolt, P.C.D. 44 mm | 6-bolt | 6-bolt |
| Pad compound | Resin only | Resin only | Listed for metal-pad calipers |
| Sizes we sell | 160 mm and 180 mm | 160 mm and 180 mm on separate pages | Not opened in this batch |
| Fixing | Anti-loosen tightening plates included | See that page | Not compared here |
The SM-RT54 is also resin-only on Shimano's compatibility list. This page is the SM-RT56.
Specifications
| Brand | Shimano |
|---|---|
| Model | SM-RT56 |
| Series | SHIMANO (the current spec table does not name Deore or another group) |
| Part numbers | 160 mm: ESMRT56SC; 180 mm: ESMRT56MC |
| Mount | 6-bolt (P.C.D. 44 mm) |
| Outside diameter | 160 mm, 180 mm |
| Pad shape | Narrow and wide |
| Pad compound | Resin only |
| Remarks | With anti-loosen tightening plates |
| Minimum thickness | 1.5 mm (etched Min.TH=1.5) |
| Colour | Silver |
Source: Shimano product specification, matching on the North America, Australia, Taiwan and Japan pages. Minimum thickness and rotation come from the etching on Shimano's product photo. Stainless one-piece construction is from bike-components and BIKE24. The official table does not list material or weight, so weight is not in this table.
In the box
- One SM-RT56 rotor in the diameter you select
- 6-bolt fixing screws and anti-loosen tightening plates. bike-components lists 6 screws and 3 plates
Our supplier listing has no barcode for this rotor. If the box print shows another size, the diameter you selected on this page is the one we sell.
FAQ
Can I use metal pads?
No. The SM-RT56 is for resin pads only. Shimano states that metal pads easily damage rotors in this resin-only group. Organic and resin refer to the same pad compound.
Is this 6-bolt or Center Lock?
6-bolt, with a 44 mm bolt-circle diameter. It is not Center Lock. A Center Lock hub needs a separate adapter. Contact us before ordering if that is your hub.
Should I choose 160 mm or 180 mm?
Use the maximum diameter your frame and fork allow, and do not go past it. This page offers 160 mm (ESMRT56SC) and 180 mm (ESMRT56MC). Whether 180 mm needs an adapter depends on the mount already on the bike.
How does the SM-RT56 differ from the SM-RT26 and SM-RT66?
The SM-RT26 and SM-RT56 are both resin-only. The SM-RT66 is listed for calipers that use metal pads; the SM-RT56 is not. Our SM-RT26 rotors are on separate pages for 160 mm and 180 mm.
How thin is too thin?
The face is etched with a minimum thickness of 1.5 mm. Replace the rotor below that, or if it is clearly warped or deeply grooved. Shimano does not give a time limit, so age alone is not the test.
Which way does it face, and what is the bolt torque?
Follow the ROTATION arrow so it matches the wheel's forward direction, and use the anti-loosen plates supplied. The official specification table does not list a torque figure, so tighten the bolts evenly with those plates rather than guessing a number.
Will it rust, squeal, or overheat?
The rotor is stainless steel. In humid weather the face can still discolour; discolour alone is not a reason to replace it. Resin pads are usually quieter than metal, but long descents still heat the rotor, and this is not a floating design. Noise is worth checking against pad compound, oil on the face, and rotation direction.
What does it weigh?
Shimano's specification table does not list weight, so this page does not treat a gram figure as official. Some overseas retailers quote about 135 g for 160 mm and 151 g for 180 mm. Treat those as retailer figures only.
Specifications and components follow the manufacturer's latest release and may change without notice. If in doubt, please contact us to confirm before ordering.
Last updated: October 2026
