AI 速览
- BR-R9270 (Dura-Ace) calipers: MONO-BODY one-piece forged, 233 g/set, K05Ti-RX resin pads, ICE TECH, mineral oil — the benchmark for road disc braking
- RT-CL900 rotors (Dura-Ace): 140 mm = 96 g, 160 mm = 116 g; FREEZA cooling fins; RT-CL800 (Ultegra) same weight at 40% lower cost
- ST-R9270 Di2 levers (Dura-Ace): 175 g each; wireless shifting + hydraulic braking; R8170/R7170 same ergonomics with incremental weight penalties
- Official dealer manuals (DM-RADBR10) and exploded views linked for every component — sourced from si.shimano.com
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Why this page exists
Shimano's official website is product-marketing-first — not reference-first. Spec tables are scattered across product pages, dealer manuals (si.shimano.com) are gated behind cookie-walls, and cross-tier comparisons simply don't exist on their site. This page is the spec reference I wish existed: all the numbers for the current-generation road disc brake lineup, in one place, with links to the original PDFs and dealer docs where you can verify every claim.
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Brake Calipers
All three calipers share the Shimano Flat Mount system, ONE WAY BLEEDING (simplified hydraulic bleed), and ICE TECHNOLOGIES pad compatibility. The differences are materials, weight, and pad clearance. The Dura-Ace BR-R9270 uses MONO-BODY construction (machined from a single cold-forged block); Ultegra and 105 use multi-piece construction that is marginally heavier but functionally equivalent.
Road disc brake caliper comparison: R9200 · R8100 · R7100
| Spec | BR-R9270 (Dura-Ace) | BR-R8170 (Ultegra) | BR-R7170 (105) |
|---|---|---|---|
| Series | DURA-ACE R9200 (12s Di2) | ULTEGRA R8100 (12s Di2) | SHIMANO 105 R7100 (12s Di2) |
| Construction | MONO-BODY (1-piece forged) | 2-piece | 2-piece |
| Weight (set, F+R) | ~233 g | ~282 g | ~320 g |
| Pad clearance | Standard | +10% wider (less rotor rub) | +10% wider |
| Recommended pads | K05Ti-RX Resin (w/o fin), L05A-RF Resin (w/ fin) | K05Ti-RX Resin, L05A-RF Resin | K05Ti-RX Resin, L05A-RF Resin |
| Recommended rotor | RT-CL900 / RT-MT900 | RT-CL800 / RT-MT800 | RT-CL700 / RT-MT800 |
| Fluid | Shimano mineral oil | Shimano mineral oil | Shimano mineral oil |
| Mount type | Flat Mount | Flat Mount | Flat Mount |
| Piston count | 2-piston opposed | 2-piston opposed | 2-piston opposed |
| Rotor size range | 140 mm (F+R), 160 mm (F only) | 140–160 mm | 140–160 mm |
| Caliper material | Aluminum (forged, anodized) | Aluminum | Aluminum |
| Approx. retail (USD) | $225–230 (front), $225 (rear) | ~$160 each | ~$110 each |
| Dealer manual | DM-RADBR10 (PDF) | DM-RADBR10 (PDF) | DM-RADBR10 (PDF) |
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Disc Brake Rotors
Shimano road rotors use a 3-layer ICE TECHNOLOGIES sandwich (stainless steel braking surface + aluminum core + stainless steel carrier) for heat dissipation. The FREEZA variant (CL900, CL800) adds painted radiator fins. Rotors are Center Lock mount and cross-compatible across all road groupsets — you can run RT-CL900 rotors on a 105 bike. MTB XTR rotors (RT-MT900) are lighter and also cross-compatible on road hubs.
Center Lock disc rotor comparison
| Spec | RT-CL900 (Dura-Ace) | RT-CL800 (Ultegra) | RT-CL700 (105) | RT-MT900 (XTR, MTB) |
|---|---|---|---|---|
| Weight (140 mm) | 96 g | 95 g | ~110 g | 85 g |
| Weight (160 mm) | 116 g | 113 g | ~130 g | 106 g |
| Sizes available | 140, 160, 180, 203 mm | 140, 160 mm | 140, 160 mm | 140, 160, 180, 203 mm |
| Technology | ICE TECH FREEZA (painted fins) | ICE TECH FREEZA (painted fins) | ICE TECH | ICE TECH FREEZA |
| Arm design | Revised arm profile (reduced warp) | Same as CL900 | Simplified arms | 5-arm (≥180 mm), 4-arm (≤160 mm) |
| Lock ring weight | ~7 g (aluminum) | ~7 g (aluminum) | ~10 g (steel) | ~7 g (aluminum) |
| Approx. retail (USD) | $95–110 | $61–70 | $50 | $80–85 |
| Compatible pads | Resin (K05Ti-RX, L05A-RF) | Resin (K05Ti-RX, L05A-RF) | Resin only | Resin / Metal (D02S-MX) |
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Levers & Shifters
All three tiers use Shimano's Di2 wireless platform for shifting. The hydraulic brake lever shares the same basic architecture across tiers. Weight increases as you go down the range, mainly from material substitutions (carbon lever blades → aluminum, titanium hardware → steel). The brake master cylinder and servo-wave mechanism are identical across all three — brake feel and modulation are functionally equivalent.
Di2 hydraulic shift/brake lever comparison
| Spec | ST-R9270 (Dura-Ace) | ST-R8170 (Ultegra) | ST-R7170 (105) |
|---|---|---|---|
| Weight (per lever) | 175 g | ~195 g | ~220 g |
| Shifting | Di2 wireless, 2 buttons/lever | Di2 wireless, 2 buttons/lever | Di2 wireless, 2 buttons/lever |
| Lever blade material | Carbon | Carbon | Aluminum |
| Reach adjust | Tool-free dial | Tool-free dial | Tool-required (hex) |
| Brake caliper pairing | BR-R9270 | BR-R8170 | BR-R7170 |
| Servo-Wave | Yes | Yes | Yes |
| Hood shape | Slim, textured | Same as R9270 | Same as R9270 |
| Approx. retail (USD) | $680 each | ~$450 each | ~$280 each |
| Dealer manual | DM-RADBR10 (PDF) | DM-RADBR10 (PDF) | DM-RADBR10 (PDF) |
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Compatibility Matrix
All R9200/R8100/R7100 components are cross-compatible within the 12-speed Di2 road ecosystem. You can mix and match: run a Dura-Ace caliper with Ultegra levers, pair 105 shifters with Dura-Ace rotors, etc. Brake hoses use the same SM-BH90-JK-SSR standard across all tiers. Mineral oil only — do not use DOT fluid.
The only hard incompatibility: BR-R9270 does not support rear 180 mm rotors. Rear max is 160 mm for Dura-Ace calipers. Ultegra and 105 calipers accept 140–160 mm front and rear. For 180+ mm rotors, use RT-MT900 (XTR) with a flat-mount adapter.
/ 来源
资料与延伸阅读
- Shimano BR-R9270 product page
- Shimano BR-R8170 product page
- Shimano BR-R7170 product page
- Shimano RT-CL900 product page
- Canadian Cycling Magazine: R9200 weights & pricing
- Mr. MAMIL: Shimano Dura-Ace vs XTR rotor comparison
- Hands On Bike: CL900 vs MT900 vs RT900 rotor comparison
- Shimano Dealer Manual DM-RADBR10 (PDF)
- Shimano BR-R9270 Exploded View (PDF)