## What are the standard BCD for chainring?

On a chainring with 4 bolts, the BCD is the distance between two bolts across from each other….How to measure Bolt Circle Diameter (BCD)

BCD | Distance (mm) | Distance (in) |
---|---|---|

102mm | 72.1mm | 2.84in |

104mm | 73.5mm | 2.90in |

110mm Shimano – asymmetrical | 63.6mm; 90.6mm | 2.50in; 3.56in |

110mm SRAM – asymmetrical | 64.8mm; 89.3mm | 2.55in; 2.51in |

**What is the smallest chainring for 104 BCD?**

AbsoluteBLACK 30t oval chainring

The AbsoluteBLACK 30t oval chainring is the smallest 104 BCD compatible chainring in the world, and it’s taken some clever engineering to make it happen.

### What is a 104 BCD crank?

104 BCD is the most common bolt pattern on double and triple cranksets and happens to be the first product ever made by Wolf Tooth Components. The Drop-Stop® tooth design is the best performing and longest lasting wide/narrow chainrings on the market.

**What is the smallest chainring?**

The award for the smallest chainring on a road crankset goes to Middleburn with their 94/58 BCD “Incy” chainring spider (removable). The “Incy” spider offers a small front chainring as low as 20 teeth!

## How do I choose chainrings?

The larger chainring gives you bigger, harder to turn gears that move you further per pedal revolution – so it’s suitable for higher speeds – while the smaller chainring gives you gears that are easier to turn but move you a shorter distance per pedal revolution – so it’s suitable for lower speeds, including riding …

**What BCD do Navy Seals use?**

BC-72. This is a unit for the advanced or professional diver. It is designed around a fully-featured back inflation buoyancy compensator device with its technical style inner air-cell and protective three-dimensional Nylon/Cordura outer shell.

### What BCD is Shimano Tiagra?

110mm BCD

Shimano Tiagra FC-4700 110mm BCD 4 Arm Outer Chainring – 52T-ML.

**What is BCD on a bike chain?**

BCD defines the positioning of the chainring bolt holes diametrical location. In layman’s terms, it’s the size of the mounting for the chainrings, and it must match for the crank and chainrings or they won’t mount up.

## What does 104/64 BCD mean on a chainring?

On triple cranks, and on most mountain 2×10 (and 2×11) set-ups, there are 2 Bolt Circle Diameters — one for the large ring (or rings), and one for the small chainring. In this case, they are usually designated as something like 104/64 BCD. That means 104 mm bolt circle diameter for the larger ring, and a 64 mm diameter for the smaller ring.

**What is the diameter of a BCD bolt?**

In this case, they are usually designated as something like 104/64 BCD. That means 104 mm bolt circle diameter for the larger ring, and a 64 mm diameter for the smaller ring.

### How do I find the correct chainrings for my bike?

Find the number of bolts in the circle (Left Column) and the approximate measurement (metric or English) between adjacent holes. Find those numbers in the table, then in the Right Column you’ll see the Bolt Circle Diameter (BCD). Use this information to buy the correct chainrings for your bike.