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Prototype - Evolving Daily

TRP HY/RD Front Caliper

What the checker says29will not fit

Run variant by variant through the gravel bike builder’s own engine. Every sentence below is the checker’s, unedited. Nothing here says this part fits your bike; it says what it does and does not fit among the parts we hold.

Checked against 854 verified gravel bike parts in this catalog. 843 produced no finding of any kind; that is HY/RD (Flat Mount). HY/RD (Post Mount) clears 823. Each variant produces 3 to 26 distinct errors and 0 distinct warnings.

Will not fit

  • Will not fiterror · Front RotorFront rotor too big for the caliper: 180mm exceeds the TRP HY/RD (Flat Mount) caliper's maker-stated maximum of 160mm - the flat-mount system has no size-up bracket, so no adapter can make it fit. On 6 of the 30 verified rotors in this catalog. Applies to 1 of 2 variants.
  • Will not fiterror · Front RotorFront rotor too big for the caliper: 203mm exceeds the TRP HY/RD (Flat Mount) caliper's maker-stated maximum of 160mm - the flat-mount system has no size-up bracket, so no adapter can make it fit. On 4 of the 30 verified rotors in this catalog. Applies to 1 of 2 variants.
  • Will not fiterror · ForkFront brake mount: TRP HY/RD (Post Mount) is a post-mount caliper and Fox 32 Taper-Cast has a flat mount - two different mounting standards, so the caliper does not bolt on as it is. The part that bridges them is a rotor-size-specific flat-mount-to-post-mount adapter. A shim or adapter may make other sizes or standards work, but that is a modification, not a fit. On 2 of the 31 verified forks in this catalog. Applies to 1 of 2 variants.
  • Will not fiterror · ForkFront brake mount: TRP HY/RD (Post Mount) is a post-mount caliper and RockShox Rudy Ultimate XPLR has a flat mount - two different mounting standards, so the caliper does not bolt on as it is. The part that bridges them is a rotor-size-specific flat-mount-to-post-mount adapter. A shim or adapter may make other sizes or standards work, but that is a modification, not a fit. On 2 of the 31 verified forks in this catalog. Applies to 1 of 2 variants.
  • Will not fiterror · ForkFront brake mount: TRP HY/RD (Post Mount) is a post-mount caliper and RockShox Rudy XL Ultimate has a flat mount - two different mounting standards, so the caliper does not bolt on as it is. The part that bridges them is a rotor-size-specific flat-mount-to-post-mount adapter. A shim or adapter may make other sizes or standards work, but that is a modification, not a fit. On 2 of the 31 verified forks in this catalog. Applies to 1 of 2 variants.
  • Will not fiterror · ForkFront brake mount: TRP HY/RD (Post Mount) is a post-mount caliper and RockShox Rudy XL has a flat mount - two different mounting standards, so the caliper does not bolt on as it is. The part that bridges them is a rotor-size-specific flat-mount-to-post-mount adapter. A shim or adapter may make other sizes or standards work, but that is a modification, not a fit. On 2 of the 31 verified forks in this catalog. Applies to 1 of 2 variants.
  • Will not fiterror · ForkFront brake mount: TRP HY/RD (Post Mount) is a post-mount caliper and RockShox Rudy XPLR (Base) has a flat mount - two different mounting standards, so the caliper does not bolt on as it is. The part that bridges them is a rotor-size-specific flat-mount-to-post-mount adapter. A shim or adapter may make other sizes or standards work, but that is a modification, not a fit. On 2 of the 31 verified forks in this catalog. Applies to 1 of 2 variants.

Rg brake mount, Fork. 21 more findings from the same check, on up to 1 of the 31 verified forks each.

Rg brake rotor max, Front Rotor. 1 more finding from the same check, on up to 1 of the 30 verified rotors each.

Open a variant in the builder to see the ones that apply to your own parts.

The checker compares the dimensions listed in what we check, and what we don’t. “No conflicts found” means no conflict among those dimensions — not a guarantee that a build works. Errors mean it won’t fit; warnings mean it works but check; infos are notes.

$149.99 MSRP·205 g

What the maker states

Mount
flat-mount caliper (on 1 of 2 variants); post-mount caliper (on 1 of 2 variants)
Pistons
2-piston caliper
Maximum rotor
Rotor up to 160 mm (on 1 of 2 variants)
Actuation
Mechanical
Brake system
Disc-mechanical
Maximum rotor evidence
Maximum rotor evidence: stated-maximum (on 1 of 2 variants)

A value shown as a set or a range differs between this model’s variants and is never one variant’s spec.

2 verified variants

VariantMountMaximum rotorMaximum rotor evidencePrice (MSRP)WeightSourceLast checkedBuild
HY/RD (Flat Mount)flat-mount caliperRotor up to 160 mmstated-maximum$149.99205 gmaker’s page2026-08-10Build with this
HY/RD (Post Mount)post-mount calipernot statednot stated$149.99205 gmaker’s page2026-08-10Build with this
The rest of what the maker states6 not published

6 further fields the checker looks for are not published by TRP, so we leave them blank rather than estimate them, and those 6 checks stay silent on this front caliper. They are excludes rotor, brake fluid, brake closed system, lever makers, design rotor thickness and design rotor thickness maximum. Each is recorded as “not stated by the maker (not checked)”.

Source: each variant links the maker’s own page in the table above. Last checked 2026-08-10.

Checked against

The checker ran this model against every verified part below that it has a slot for, the same way it checks a build in the builder. What follows is the verdict it actually produced for that specific pairing — not a recommendation, and not a guarantee any of these parts fits your own bike.

6 of 497 counterparts with a page of their own that the checker actually probed this model against, in alphabetical order by brand and model — never by price, popularity or the verdict itself.

Where this sits

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