Shimano CUES ST-U6030 / BR-U6030 Front Hydraulic Disc Brake Set
$1,280.00
Color Options
BlackSize Options
This front set is a left 2-speed hydraulic brake, not a caliper on its own. The Shimano CUES front hydraulic disc brake set pairs the ST-U6030-L dual-control lever with the BR-U6030-F flat-mount caliper. Two pistons, Shimano mineral oil, and official rotor support for 160 mm and 180 mm.
At a glance
- Category: Shimano CUES hydraulic disc brake set, front
- Brand: Shimano (Japan)
- Models: ST-U6030-L lever, BR-U6030-F caliper
- Shifting: left side, 2-speed, for a front derailleur (double chainring)
- Caliper: flat mount, 2 resin pistons, standard pad B05S-RX resin without a fin
- Rotors: 160 mm and 180 mm. 140 mm, 200 mm, 203 mm and 220 mm are not listed
- Fluid: Shimano mineral oil. SERVOWAVE is not on the official specification
- Clamp: 23.8–24.2 mm, with reach adjust
- Best for: drop-bar bikes with a double chainring that already use, or are moving to, CUES LINKGLIDE
The left lever also shifts the front chainring
A front brake search often means “the brake for the front wheel”. ST-U6030-L does that and also shifts a 2-speed front derailleur. A 1x bike usually needs a brake-only left lever. If the bike has no front derailleur, contact us with photos of the bar and chainrings before ordering.
The matching right-hand 11/10-speed lever and rear caliper are the Shimano CUES ST-U6030 / BR-U6030 rear hydraulic disc brake set. A double-chainring bike needs both. Both pages are still drafts, so the links open on the shop only after both are published.
Which bikes it suits
- Drop bars with a 23.8–24.2 mm clamp, and a flat-mount fork
- A double chainring that needs a 2-speed front shift on CUES or LINKGLIDE
- A front rotor of 160 mm or 180 mm
Do not assume it fits a flat bar, a 22.2 mm clamp, a post-mount fork, or a 203 mm rotor. The cable lever ST-U3030-L is a mechanical NEW SUPER SLR lever and does not replace this hydraulic lever.
What matters on this set
Flat-mount, 2-piston, built around a 160 mm rotor
Shimano describes the CUES flat-mount hydraulic brake as an integrated design for the widely used 160 mm rotor, so a separate adapter is not part of that idea, with a simple 2-piston body. The specification also marks 180 mm as compatible, and leaves 140 mm and 203 mm unmarked. The standard pad is B05S-RX resin without a fin. ICE TECHNOLOGIES pads are not listed as compatible.
Mineral oil, funnel bleeding and ONE WAY BLEEDING
The fluid is SHIMANO Mineral. Do not fill the system with DOT fluid. The caliper has ONE WAY BLEEDING and the lever has funnel bleeding. The kit hose is SM-BH59-JK-SSR, black, with a straight joint. The caliper specification marks J-kit for OEM builds. Hose length is not in the specification table used here, so this page does not state one.
Reach adjust, drop-bar clamp
Shimano’s ST-U6030 description says the lever shape shortens the reach from the bar. The table confirms reach adjust and a 23.8–24.2 mm clamp. The “up to 2 gears per sweep” note applies to the right lever, not this left 2-speed lever.
Front set and rear set
| Front set (this page) | Rear set | |
|---|---|---|
| Lever | ST-U6030-L, left | ST-U6030-R, right |
| Shifting | Front, 2-speed | Rear, 11/10-speed, up to 2 gears per sweep |
| Caliper | BR-U6030-F | BR-U6030-R |
| Mount | Flat mount, 2-piston | Flat mount, 2-piston |
| Pad | B05S-RX resin | B05S-RX resin |
| Rotors | 160 mm, 180 mm | 160 mm, 180 mm |
| Fluid | Shimano mineral oil | Shimano mineral oil |
Comparison source: Shimano productinfo specification tables.
Contact us before ordering
A hydraulic brake with the wrong mount or rotor size is awkward to sort out after it arrives. Contact us with the bar diameter, whether the fork is flat mount or post mount, the rotor size, and whether the bike is 1x or 2x. We can check from photos before ordering.
Specifications
| Brand | Shimano CUES |
|---|---|
| Lever | ST-U6030-L |
| Caliper | BR-U6030-F |
| Lever type | Hydraulic DUAL CONTROL LEVER |
| Front speeds | 2 |
| Recommended caliper | BR-U6030, BR-RS405 |
| Recommended lever (caliper table) | ST-U6030, BL-U6030-L, ST-U4030, BL-U4030-L |
| Hose (kit) | SM-BH59-JK-SSR, black, straight joint |
| Fluid | SHIMANO Mineral |
| Mount | Flat mount |
| Pistons | 2, resin |
| Caliper material | Aluminum, painted |
| Standard pad | B05S-RX resin (without fin) |
| Rotors | 160 mm, 180 mm |
| Clamp band | 23.8–24.2 mm |
| Reach adjust | Yes |
| Bleeding | Funnel bleeding, ONE WAY BLEEDING |
| J-kit | Marked for OEM specification |
| Official weight | Not published (shown as “-”), so this page leaves it out |
Source: Shimano productinfo (ST-U6030-L, BR-U6030-F) and the bike.shimano.com product description.
What is in the set
The distributor lists this code as a front brake set for ST-U6030-L and BR-U6030-F, with a resin pad. Shimano’s caliper specification describes the kit weight setup as including the standard pad and two fixing screws, without an adapter. A rotor is not part of that description; use a 160 mm or 180 mm rotor. Hose length, and whether a full bottle of mineral oil is in the box, are not stated in the table. Ask us if you need that confirmed.
FAQ
Can this brake use DOT fluid?
No. The official fluid is SHIMANO Mineral oil. Bleed it with a Shimano funnel and mineral oil, and do not mix in DOT fluid.
Will it take a 203 mm or 140 mm rotor?
No. BR-U6030-F is marked for 160 mm and 180 mm only. 140 mm, 200 mm, 203 mm and 220 mm are not marked.
Can a 1x bike use this set as the front brake?
Do not assume so. ST-U6030-L is a 2-speed front shifting lever for a double chainring. If the left side only needs a brake, contact us before ordering.
How is this different from the ST-U3030 lever?
This set is hydraulic. ST-U3030 is a mechanical cable lever on Shimano NEW SUPER SLR and does not operate a BR-U6030 hydraulic caliper. The cable left lever is ST-U3030-L.
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
