Shimano Acera BR-MT420 Post Mount Hydraulic Disc Brake Caliper (Black)
EBRMT420MPRXL
A hydraulic disc caliper for riders who want stronger, more consistent stopping power without upgrading their whole brake system.
Overview
The BR-MT420 sits in Shimano's entry-level hydraulic disc lineup, built around a 4-piston caliper design that Shimano positions as a meaningful step up from 2-piston calipers in raw stopping power.
It's a straightforward, no-frills caliper - no lever included, just the caliper body and pads - which makes it a natural pick for anyone upgrading an existing hydraulic setup or building a bike from parts. The painted aluminium body keeps weight reasonable while the 4-piston layout spreads clamping force more evenly across the pad, which is where a lot of that extra stopping power and improved wear resistance actually comes from.
It makes sense as a targeted upgrade for a rider who's happy with their current shifters and levers but wants noticeably stronger, more consistent braking - rather than a full groupset swap just to fix underpowered stopping power.
Why You'll Like It
4-piston caliper design
More braking power and better modulation than a 2-piston caliper, especially useful on loaded bikes or steeper terrain.
D03S resin pads included
A quiet, easy-modulating pad compound straight out of the box, with D02S metal pads available as an upgrade if you want more bite in wet or muddy conditions.
Wide rotor compatibility
Works with SM-RT30, SM-RT54, SM-RT56, and SM-RT64 rotors from 140mm up to 203mm, so it fits a wide range of frame and fork setups.
Post mount design
Straightforward to fit on most post-mount frames and forks without needing an adapter for a standard setup.
Who Is It For?
Riders upgrading an older or lower-spec hydraulic disc setup who want noticeably stronger braking without replacing shifters or levers. Also a solid pick for anyone building or maintaining a bike from individual parts who needs a dependable, well-priced caliper.
It's a practical fit for riders dealing with the steeper, less predictable braking demands of Indian traffic and terrain - loaded commutes, sudden stops in city riding, or steep sections on longer rides - where the extra stopping power of a 4-piston caliper over a 2-piston setup is genuinely noticeable.
Good to Know
- This caliper ships without a mount adapter, so check your frame or fork's native mount spacing against your chosen rotor size before fitting.
- It comes fitted with D03S resin pads - if you later want to switch to D02S metal pads for wet-weather bite, both compounds are compatible with this caliper.
- Because it's sold as a caliper only, it pairs well with your existing brake lever when you're upgrading just the stopping power side of your setup.
Technical Specifications
- Mount Type: Post Mount
- Number of Pistons: 4
- Brake Pad Compound: D03S Resin (included); D02S Metal compatible
- Recommended Rotors: SM-RT30, SM-RT54, SM-RT56 (resin pads), SM-RT64 (resin or metal pads); 140-203mm diameter range
- Includes: Brake Caliper (pads included, adapter and rotor sold separately)
- Caliper Material: Painted aluminium body, steel hardware
Additional Information
- Country of Origin: Malayasia
- Imported By: Shimano South Asia Pvt Ltd., 19, (Ground Floor) Kumara Krupa Road, Bangalore - 560 001, Karnataka, India
- Net Quantity: 1N
- Customer Care Address: 291, 10 Main, 5 Block, Jayanagar, Bangalore - 560041. Ph: (080)47183232, Email: support@bumsonthesaddle.com
- Commodity: Caliper Brakes