SRAM post-mount disc brake adapter 20 mm — Black/Rainbow with stainless steel bolts

The SRAM Post Bracket 20P Standard Mount is a post-mount disc brake adapter that lets you install compatible calipers on frames not originally designed for them, and it ships with stainless steel mounting bolts for secure fitting.

When upgrading or repairing bicycles that lack factory disc-brake fittings, the right adapter can restore proper rotor-to-caliper alignment and reliable braking performance. The SRAM 20P adapter is intended for post-mount setups and includes stainless steel bolts (rainbow finish) to fasten the caliper to the frame or fork. Note that this adapter targets specific frame geometries and is not a one-size-fits-all solution; some frames require thin washers or additional spacing to achieve correct alignment.

How does this adapter help fit post-mount disc calipers to non-standard frames?

The SRAM 20P adapter converts existing mounting points to accept post-mount calipers, aligning the caliper so it grips the rotor correctly. It provides a secure interface between caliper and frame or fork, preventing misalignment and rubbing.

• Converts compatible frame mounts to a 20P standard post mount orientation.
• Includes stainless steel rainbow bolts for corrosion-resistant fastening.
• Engineered specifically for disc brake applications to maintain consistent clearance.
• May require thin washers on some frames to fine-tune alignment.

Will these mounting bolts work on any post-mount caliper?

The included stainless steel bolts are sized for the intended post-mount interface and are compatible with many post-mount calipers, but compatibility depends on caliper thread and frame spacing. Always verify dimensions before installation.

• Stainless steel fasteners resist corrosion for long-term use outdoors.
• Designed for Avid-style post bracket installs; check caliper thread pitch and length.
• If bolt length or thread differs, replacement bolts of correct spec may be necessary.
• Not a universal adapter—measure twice, install once.

What installation issues should I expect during fitting?

Installation is straightforward for compatible frames, but some bicycle models need thin washers to correct spacing or rotor alignment. Tighten hardware to the manufacturer torque specification and confirm rotor runs free without contact.

• Some frames require washers between adapter and frame to achieve correct caliper position.
• Check rotor-to-pad clearance and adjust before final torqueing.
• Use appropriate torque to avoid stripped threads or damaged components.
• Inspect for interference with nearby frame or brake hose routing.

How do I know if this adapter is right for my bike?

This adapter is suited for riders upgrading to post-mount disc calipers on frames lacking the exact factory mount. It’s ideal when your caliper type matches post-mount standards and the frame has compatible mounting points.

• Choose if your caliper is a post-mount design and your frame needs a 20P-style bracket.
• Verify mounting hole spacing and thread compatibility first.
• Not suitable if your frame has a flat-mount standard or unique proprietary mounts.
• Consider a professional bike shop installation if unsure about fitment.

Who this is for: Cyclists, mechanics, and bike shops seeking a reliable post-mount adapter for disc brake retrofits will value the SRAM 20P bracket. It’s a practical option for riders converting wheels or upgrading braking systems when their frame lacks a factory post-mount tab, provided dimensions match and minor shimming is acceptable. If your bike uses a flat mount or an uncommon proprietary interface, consult measured specifications or a professional mechanic before purchasing.