SUMC · FLAT TOP CHAIN · SRAM
S12 PRO — SRAM-Tuned Flat-Top, Gold Finish
Built on SUMC's flat-top link-plate platform and tuned specifically for SRAM 12-speed drivetrains, the S12 PRO pairs a crescent outer plate with SUMC's patented oil-storing sealed pins for a chain that runs quiet and stays lubricated from the inside out.
10,000 KM
Rated Riding Distance, Oil-Sealed Pins
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Flat-Top DesignSUMC's flat-top (crescent) chain platform, tuned specifically for SRAM drivetrains.
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Oil-Sealed PinsPatented O-ring seals keep lubricant inside every roller, rated for up to 10,000km of riding.
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SL, EL, or No Suffix: What the Name Tells You
SUMC's tier naming isn't just marketing — it describes exactly how the chain is machined. This is an SL (Super Light) chain: it has hollow pins AND cut-out side plates, the lightest construction SUMC builds, bringing this 12-speed flat-top chain down to just 256g. Step down a tier to EL and the pins become solid while the side plates keep their cut-outs, landing at 268.5g. Chains with no suffix at all use solid pins and solid side plates throughout — the sturdiest and heaviest of the three, at 274.3g. As more material is machined away, weight drops and price rises, so you can pick the tier that matches how much you're willing to spend to save grams.
| Tier |
Pins |
Side Plates |
Weight |
| SL |
Hollow |
Cut-out |
256g |
| EL |
Solid |
Cut-out |
268.5g |
| No suffix |
Solid |
Solid |
274.3g |
Shimano vs SRAM: What Actually Differs
Shimano and SRAM chains of the same speed count share the same nominal chain pitch, but the two brands tune inner link width, pin length, and outer-plate chamfering differently to match their own derailleur cage geometry, cassette tooth-ramp profile, and quick-link design — Shimano's own quick-link versus SRAM's PowerLock/Flattop link. This S12 PRO is built and dimensioned as the SRAM-tuned version of SUMC's flat-top platform.
Why SUMC?
SUMC is a dedicated Chinese chain manufacturer whose oil-storing sealed pin technology (patent ZL 2024 2 1214393.1) traps lubricant at every joint instead of relying on surface oiling alone. Combined with a 4-micron anti-corrosion coating tested through 1000+ hours of salt spray, the S12 PRO is built to run clean and quiet well past where an ordinary chain would need relubing.
Specifications
| Speed |
12-Speed |
| Compatibility |
SRAM 12-speed drivetrains |
| Link Design |
Flat-top (crescent) outer plate |
| Chain Pitch |
1/2" x 11/128" |
| Finish |
Gold |
| Links |
126 |
SKU: SMC-SRAM-S12SL-PRO-GLD
