Information

These are the inner VBC (Variable Bolt Circle) chainrings and will fit either style of outer VBC rings for the M/A/R/G 30 cranks or ENO/Square Taper Road cranks.  Chainring “sets” are available on the “VBC Chainring Sets” page.

When Doug saw the limitations presented by all the different bolt-circle diameters required to manufacture chainrings, he figured there had to be a better way.  “Hey, how about no standard?”, and the VBC chainring system was born.  VBC stands for “Variable Bolt Circle” and replaces several different bolt patterns with one simple, slotted outer chainring design that accepts a wide range of our inner VBC chainrings.  The outer chainring mounts directly to the crank and serves as the mounting point for the inner chainring.

As bikes, drivetrains, and riding styles have changed in the last decade, the VBC system has found a following among riders tired of being told what gear ratios they should be using.  Available in 39 “recommended” combinations, there’s no other system that allows this level of customization!

Features

• Compatible with White Industries cranks only
• Chainrings are made from  U.S. sourced 7075-T6 aluminum
• Available in black anodize only
• Available to fit either M/A/R/G cranks (30mm) or ENO/Road Square Taper cranks (17mm)
  • The outer rings are specific to which style of crank you have ie 30mm or 17mm
    • Each crank uses a different spline configuration for the outer ring
• Inner VBC chainrings are the same for either crank style
• Chainring “sets” come assembled together with White Industries VBC-specific hardware
  • Hardware available separately (see Chainrings>VBC Bolt/Shift Hardware Set)
• Outer VBC chainrings cannot be used without an inner chainring!  They are not stiff enough by themselves!

Specs

• Inner VBC rings are engraved with “Inside”, which should face toward the frame
• Compatible with 9, 10, and 11 speed drivetrains only
  • 12 speed chains are too narrow and will fall/jam between the rings
• We recommend Shimano front derailleurs only for best shifting performance
•  To ensure proper shifting we recommended inner/outer chainring combinations of:
  • A difference no smaller than 10 teeth
  • A difference no bigger than 20 teeth
• Inner chainrings are available from 24t to 38t in 2 teeth increments
• Outer chainrings are available from 38t to 52t in 2 teeth increments

Torque

• VBC bolts: 7 ft lbs (10 Nm)