MADISON NEGRO CONTRASTE  Rear hub

Technical Description

Madison Black Contrast is intended for track, fixed gear, and urban bicycles. The hubs are manufactured from round bars of 6061 aluminum, not forged, through multiple CNC machining processes, ensuring dimensional precision, structural strength, and durability.

A distinctive feature of this model is the additional machining and bright polishing process on both sides of the flanges, creating the visual contrast between the black anodized (not painted) body and the polished surfaces, while maintaining precise tolerances in the spoke support areas. Anodizing is a treatment that improves resistance to surface wear and corrosion, maintaining color and finish under intensive use without altering tolerances.

Adjustment Type

Fixing system: hexagonal nut

Nut size: 15 mm

Nut material: SAE 1045 steel

Surface treatment: chrome plated

Complement: floating washer

bearings

The assembly uses low-friction sealed 6000ZZ bearings in both the front and rear hubs. This type of bearing features double metal shields, reducing the ingress of dust and contaminants, maintaining internal lubrication, and allowing stable and consistent rotation, with low maintenance and good durability in urban and track use.

Materials

Shell: 6061 aluminum

Axle: Siemens Martin steel

Bearing cover: 6061 aluminum

Knurled locknut: AISI 304 stainless steel

Lockring: AISI 304 stainless steel

Technical Specifications

Rear hub

Use: track / fixed gear

Body material: CNC machined 6061 aluminum

Axle material: Siemens Martin 1045 steel

Bearings: 2 × sealed 6000ZZ bearings

Flange diameter: 70 mm

Over locknut distance (OLD): 120 mm

Threads

Fixed cog: 1.375" × 24 TPI

Freewheel: 1.375" × 24 TPI

Chainline — left lockring thread: ISO 33 mm (1.299")

weight

Approx. weight (fixed / free configuration): 320 g

Approx. weight (fixed / fixed configuration): 330 g

Approx. total weight (front + rear fixed/free): 560 g

Load Limit

Maximum combined rider + bicycle weight: 120 kg