Bottom Bracket Shells

The Bottom Bracket Assembly

• Is the foundation of the frame from which all geometry is referenced.

• Is the mounting point for the crankset (chainset) to the bicycle and allows the crankset to rotate freely.

• Must be able to carry the load from the riders pedaling efforts.

• Must be located so that its axis is parallel to the hub axles, and perpendicular to the vertical and longitudinal centerlines of the frame.

• Is available in a variety of diameters, widths, and methods to mount the crank bearings.

Components of the Assembly

• A spindle to which the crankset attaches.
  

• The bearings that allow the spindle and cranks to rotate.
  

• The chain rings and pedals that attach to the cranks.
  

• The above components fit into the bottom bracket shell which connects to the seat tube, down tube, and chain stays.

Compatibility

• Most bottom brackets are designed to work with specific types of frames.

• Check the instructions from the manufacturer to determine whether they will work with the type of bike you have.

Price

• Choose a price point and then make your selection based on:

  • The quality of the materials used.

  • The reputation of the manufacturer.

  • The customer service they provide.

Reviews

• Avoid buying without checking reviews on various sites to see what customers are saying about it.

Brand

• Only consider purchasing from a reputable company that is known for making quality items and backing them up with excellent customer service.

Material

• Consider compatibility, durability, and how your your bike will be ridden.

The Bottom Line

• The wide variety of bottom bracket assemblies on the market today evolved out of a demand for bicycle frames that are lighter, stiffer, and cost less to manufacture.

• With today’s emphasis on cutting edge technology and innovation, new standards are the norm rather than the exception.

• Our decision to manufacture a given standard will be based on its anticipated applications and longevity in the market.