Shimano RT-MT900 Front Rotor
What the checker says901will not fit3check before you buy128worth knowing
Run variant by variant through the mountain 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 5997 verified mountain bike parts in this catalog. 5696 produced no finding of any kind; that is RT-MT900 203mm (CL). RT-MT900 140mm (CL) clears 5324. Each variant produces 12 to 439 distinct errors and 0 to 3 distinct warnings.
Will not fit
- Will not fiterror · Front WheelFront rotor interface mismatch: Center Lock rotor on 6-bolt front hub - no adapter exists for this direction. On 180 of the 270 verified front wheels in this catalog. Applies to all 4 variants.
- Will not fiterror · Front HubFront rotor interface mismatch: Center Lock rotor on 6-bolt front hub - no adapter exists for this direction. On 21 of the 40 verified front hubs in this catalog. Applies to all 4 variants.
- Will not fiterror · ForkFront rotor too small: 140mm is below the Manitou R7 Pro 100 minimum of 160mm (its native mount size). Post-mount adapters only space the caliper up, so no adapter can make a smaller rotor fit. On 2 of the 490 verified forks in this catalog. Applies to 1 of 4 variants.
- Will not fiterror · ForkFront rotor too small: 140mm is below the Manitou R7 Pro 120 minimum of 160mm (its native mount size). Post-mount adapters only space the caliper up, so no adapter can make a smaller rotor fit. On 2 of the 490 verified forks in this catalog. Applies to 1 of 4 variants.
- Will not fiterror · ForkFront rotor too small: 140mm is below the RockShox 35 Gold RL minimum of 180mm (its native mount size). Post-mount adapters only space the caliper up, so no adapter can make a smaller rotor fit. On 2 of the 490 verified forks in this catalog. Applies to 1 of 4 variants.
- Will not fiterror · ForkFront rotor too small: 160mm is below the RockShox 35 Gold RL minimum of 180mm (its native mount size). Post-mount adapters only space the caliper up, so no adapter can make a smaller rotor fit. On 2 of the 490 verified forks in this catalog. Applies to 1 of 4 variants.
Front rotor min, Fork. 882 more findings from the same check, on up to 1 of the 490 verified forks each.
Front brake rotor max, Front Brake. 10 more findings from the same check, on up to 1 of the 92 verified brakes each.
Front brake rotor excluded, Front Brake. 3 more findings from the same check, on up to 1 of the 92 verified brakes each.
Open a variant in the builder to see the ones that apply to your own parts.
Check before you buy
- Check before you buywarning · ForkFront rotor: 203mm exceeds the fork max of 180mm. A post-mount adapter is the part that steps a caliper up to a bigger rotor, sold in the maker’s own discrete size steps (commonly +20mm, e.g. 160 to 180mm or 180 to 200mm) rather than for any gap - and not every step is offered for every caliper model, so check the maker’s own fitment before buying. On 31 of the 490 verified forks in this catalog. Applies to 1 of 4 variants.
- Check before you buywarning · ForkFront rotor: 203mm exceeds the fork max of 200mm. A post-mount adapter is the part that steps a caliper up to a bigger rotor, sold in the maker’s own discrete size steps (commonly +20mm, e.g. 160 to 180mm or 180 to 200mm) rather than for any gap - and not every step is offered for every caliper model, so check the maker’s own fitment before buying. On 22 of the 490 verified forks in this catalog. Applies to 1 of 4 variants.
- Check before you buywarning · ForkFront rotor: 203mm exceeds the fork max of 185mm. A post-mount adapter is the part that steps a caliper up to a bigger rotor, sold in the maker’s own discrete size steps (commonly +20mm, e.g. 160 to 180mm or 180 to 200mm) rather than for any gap - and not every step is offered for every caliper model, so check the maker’s own fitment before buying. On 5 of the 490 verified forks in this catalog. Applies to 1 of 4 variants.
Worth knowing
Front rotor interface unstated, Front Wheel. 116 more findings from the same check, on up to 1 of the 270 verified front wheels each.
Front rotor interface unstated, Front Hub. 12 more findings from the same check, on up to 1 of the 40 verified front hubs each.
Open a variant in the builder to see the ones that apply to your own parts.
$55.00 to $60.00 MSRP·88 to 150 g
What the maker states
- Size
- 140 mm rotor (on 1 of 4 variants); 160 mm rotor (on 1 of 4 variants); 180 mm rotor (on 1 of 4 variants); 203 mm rotor (on 1 of 4 variants)
- Mount
- Center Lock
A value shown as a set or a range differs between this model’s variants and is never one variant’s spec.
4 verified variants
| Variant | Size | Price (MSRP) | Weight | Source | Last checked | Build |
|---|---|---|---|---|---|---|
| RT-MT900 203mm (CL) | 203 mm rotor | $60.00 | 150 g | maker’s page | 2026-07-10 | Build with this |
| RT-MT900 160mm (CL) | 160 mm rotor | $58.00 | 108 g | maker’s page | 2026-07-10 | Build with this |
| RT-MT900 140mm (CL) | 140 mm rotor | $55.00 | 88 g | maker’s page | 2026-07-10 | Build with this |
| RT-MT900 180mm (CL) | 180 mm rotor | $60.00 | 132 g | maker’s page | 2026-07-10 | Build with this |
The rest of what the maker states1 not published
1 further field the checker looks for is not published by Shimano, so we leave it blank rather than estimate it, and that check stays silent on this front rotor. It is thickness. 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 2026-07-10.
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.
- 5DEV R-SPEC Trail/Enduro Cranks (Crankset) No conflicts found
- 9point8 Fall Line (Dropper Post) No conflicts found
- 9point8 Stout (31.8, 30mm) (Stem) No conflicts found
- ACID SLX 30 front (Front Wheel) No conflicts found
- ACID SLX 30 rear (Rear Wheel) No conflicts found
- Acros ZS44/ZS56 (Headset) No conflicts found
6 of 1861 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.