The EBC MD873X floating front brake rotor is a 310mm, fully floating upgrade for the stock solid front disc on liquid-cooled Triumph modern classics. It replaces Triumph’s solid front disc, part number T2023388, on models such as the Bonneville T120, Speedmaster 1200, and Bonneville Bobber. It bolts straight on with your stock caliper and wheel. It is hand built in the UK by EBC Brakes and sold individually.
A floating rotor separates the stainless braking ring from the alloy center hub. The ring can then expand and contract with heat, without the warping and vibration a one-piece solid disc can develop. You get a lighter front wheel, consistent feel under hard braking, and a more performance-focused look.
Key Features of the EBC MD873X
- Fully floating 2-piece design: a stainless steel rotor blade mounted on a lightweight alloy center hub, replacing the OEM one-piece solid disc.
- Patented SD (Square Drive) buttons: square-sided drive buttons sit in square pockets in the rotor and hub. This lets the blade float freely and prevents the “rivet lock” that causes distortion and brake judder.
- German mill-rolled stainless steel: the blade is heat treated and tempered, then precision ground for thickness and parallelism, so new pads bed in quickly.
- Full-circle X profile: the X suffix is EBC’s full-circle floating rotor design. It can be fitted on either the left or right side.
- Lighter than stock: less unsprung and rotating weight helps steering and suspension response.
- Quality assured: every EBC disc is 100% inspected for accuracy and runout, and EBC’s X Series rotors carry R90 accreditation.
- Made in the UK: hand built by trained EBC staff, not mass produced on a production line.
Specifications
- EBC part number: MD873X
- Replaces Triumph part number: T2023388 (Front Disc, Solid, Dia 310)
- Diameter: 310mm
- Type: fully floating, full circle (X Series)
- Position: front, left or right
- Quantity: sold individually (one rotor)
Fitment: Liquid-Cooled Triumph Twins
The MD873X replaces the T2023388 solid 310mm front disc fitted to these models:
- Triumph Bonneville T120 and T120 Black (2016-on)
- Triumph Speedmaster 1200 (2018-on)
- Triumph Bonneville Bobber and Bobber Black
- Triumph Thruxton 1200 (non-R models)
- Selected Bonneville T100 and Street Twin models originally fitted with the T2023388 disc
Check your original disc first. Triumph used two different 310mm front discs on its liquid-cooled 900cc twins. If your Bonneville T100, Street Twin, Street Cup, Street Scrambler, or Speed Twin 900 has disc T2021404, you need the EBC MD886X Front Brake Rotor instead. Thruxton R models with Brembo radial calipers use the EBC MD883X 310mm Front Brake Rotor. Contact us with your VIN if you are not sure.
Dual-disc models: the MD873X is priced and sold per rotor. Many 1200cc models, including the T120 and Speedmaster, use two front discs. Order two to keep both sides matched.
Installation Tips
- Follow the front wheel and brake disc procedure in Chapter 10 of your Triumph service manual, including the disc bolt torque specification.
- Clean the wheel hub mounting face so the rotor sits perfectly flat. Dirt or corrosion here can cause runout.
- Use new disc bolts or the threadlock specified in your manual. Tighten the bolts gradually in a cross pattern.
- Fit new brake pads with new rotors. Worn pads will not seat evenly on a fresh rotor surface.
- Bed in the rotor and pads with a series of moderate stops from medium speed before hard braking.
- Check that your speed sensor and ABS components are clear and working before your first ride.
EBC MD873X vs. EBC MD873 Solid Rotor
Want a like-for-like replacement for your stock disc? The EBC MD873 Front Brake Rotor is a fixed one-piece disc that replaces T2023388 directly. Choose the MD873X floating rotor if you want better heat management and less risk of warping and judder. It also cuts weight and gives your Bonneville a sportier look.
Related Parts for Your Brake Service
- Triumph Bonneville/Street Twin EBC Front Brake Rotor PN MBI-MD873 (solid OEM-type replacement)
- Triumph Bonneville T100, Street Cup, Street Twin EBC Front Brake Rotor PN MBI-MD886X (for T2021404 bikes)
- Triumph (Liquid Cooled) EBC 255mm Rear Brake Rotor PN MBI-MD874
- Triumph Bonneville 1200cc EBC Rear Brake Pads PN MBI-FA140
Learn more about EBC’s floating rotor technology on the EBC Brakes floating motorcycle rotors page.
Looking for a different rotor? Click here.
Need brake pads? Check these out.
The product images shown are for illustrative purposes only and may not be an exact representation of the product received. Manufacturers occasionally make minor cosmetic changes to items, such as color, finish, label, or design. These changes do not impact the item’s function or compatibility. Please contact us if you have specific concerns regarding appearance.
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Frequently Asked Questions
What Triumph models does the EBC MD873X floating rotor fit?
It fits liquid-cooled Triumph twins that use the T2023388 solid 310mm front disc. These include the Bonneville T120 and T120 Black, the Speedmaster 1200, the Bonneville Bobber and Bobber Black, the non-R Thruxton 1200, and some T100 and Street Twin models.
Which Triumph part number does the MD873X replace?
It replaces Triumph part number T2023388, the solid 310mm front disc.
How do I know if I need the MD873X or the MD886X?
Check the part number of your original front disc. Bikes fitted with T2023388 take the MD873X. Bikes fitted with T2021404, such as many T100, Street Twin, Street Cup, and Speed Twin 900 models, take the MD886X. If you are unsure, send us your VIN.
Is the MD873X sold as a single rotor or a pair?
The MD873X is sold individually. Models with two front discs, such as the Bonneville T120 and Speedmaster 1200, need two rotors.
Can the MD873X be fitted on either side of the wheel?
Yes. The X suffix means EBC’s full-circle floating rotor design, which can go on either the left or right side.
What is the difference between the MD873X and the MD873?
The MD873 is a solid one-piece disc that matches the stock Triumph design. The MD873X is a two-piece fully floating rotor. Its stainless blade floats on an alloy hub, so it handles heat better, resists warping, and weighs less.
What are the benefits of a floating brake rotor over a solid rotor?
A floating rotor lets the braking surface expand and contract with heat separately from the hub. This reduces warping, brake judder, and fade during hard or repeated braking. It also cuts unsprung weight for sharper steering and suspension response.
What is EBC’s SD Square Drive button system?
EBC’s SD system uses square-sided drive buttons that sit in square pockets in the rotor blade and center hub. Most rotors use round rivets, which can lock up when hot. Square buttons let the blade float freely, which prevents rivet lock, distortion, and vibration.
Do I need different brake calipers or wheels to fit the MD873X?
No. The MD873X is a direct-fit replacement for the stock T2023388 disc. It uses your original caliper, wheel, and mounting points.
Should I fit new brake pads with a new rotor?
Yes. Fresh pads seat evenly on a new rotor surface and give the best braking performance. Bed in the pads and rotor with several moderate stops before braking hard.
Where is the EBC MD873X made?
EBC Brakes hand builds the MD873X in the United Kingdom. The blades are German mill-rolled stainless steel, and every disc is inspected for accuracy and runout.
How do I know when my Triumph front brake rotor needs replacing?
Replace the rotor if it is below the minimum thickness stamped on the disc or listed in your service manual. Other signs are a pulsing brake lever, vibration or judder when braking, deep scoring, cracks, or blue heat discoloration.
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