There are a few things to keep in mind when choosing a bottom bracket for your bike.  First, you need to figure out the style of bottom bracket that fits your bike. From there, you need to select the bottom bracket that is sized correctly for your crank spindle. Finally, you will want to match your riding style to the proper bearings to ensure maximum life of the bottom bracket.  You want to make sure to get all three things right! Keep in mind as you get ready to take your measurements, that you will need to do so in the metric system. Here is more information:

Your Frame’s Bottom Bracket Shell

The first thing you need to do is measure your frame’s bottom bracket (BB) shell for yourself. Sure, you might know the actual manufacturer’s specs. However, it is important not to rely on solely on this information.  Frame manufacturers will sometimes change the specs on a bike and not update their online information.  It is much better to know exactly what the measurements are for yourself. You will need both the frame width measurement and the bottom bracket hole’s diameter in order to ensure that you correctly fit the bottom bracket to that area. 

While in there taking your measurements, you will also want to notice if you have a threaded BB shell or a press fit BB shell. The bottom bracket you choose will either be made to fit into a threaded BB shell or a press fitted BB shell. 

Know the Crankset Spindle

The next item that impacts which bottom bracket you choose will be the crankset spindle. The crankset is the part of the bike that is used to drive the chain or belt. The bottom bracket connects the crankset to the frame of the bike. It is in this way that the parts work together. 

When fitting a bottom bracket to your bike, you will need to know the diameter of the crankset spindle.  You will also need to know the effective crank spindle length. Again, these measurements are likely located in the manufacturer information for your bike specs. However, it is still a good idea to take these measurements for yourself. 

Choosing the Right Style of Bottom Bracket

At the end of the day, the style of bottom bracket you choose for your bike will be a matter of personal preference, provided that you select the one that fits correctly on your bike. Riders who use their bikes in all kinds of inclement weather and in salt air conditions need a different bearing than riders who only ride on dry and smooth pavement.  Riders who put on high miles every week will want a bearing that can withstand the mileage, but also doesn’t need to be serviced every 100 miles. You will want to work with the place where you are buying the bracket from to ensure you find the best fit. The ultimate goal is to buy the bottom bracket that will give you the most enjoyable ride. 

Generally speaking, most avid cyclists want a bottom bracket that reduces friction and performs well. They two main materials bottom brackets can be made from are ceramic or steel. Steel can be just as efficient as ceramic. Read the results from an independent study that shows how this is the case.