Size and Style

Bottom brackets come in two main designs Loose ball and Sealed ball bearing. Since this is an article aimed at buying bearings for your BMX in 2020 we will leave the loose ball bearings here. Now we have that established the next thing to decide is what type of bearing you will need. BMX frames are made in a variety of sizes and shapes and the tubing where the bottom bracket fits is no different. Bottom brackets for BMX bikes come in 19mm, 19mm mid, 22mm, 22mm mid, and 24mm. Basically, this size refers to the size of the spindle that will pass through the bearing and allows the cranks to spin. This size of your bearing will be depending on the brand of your cranks as some brands will make a specific size only. The next size to take note of is the size of the bearing case itself and this is determined by the frame style you own.  Bottom brackets come in a range of styles including Mid, Euro, USA, and Spanish. Finally, bottom brackets come in both Internal and External bottom bracket options. Internal bearing are more common in freestyle BMX where some riders opting for the external style. The classification of the bottom bracket is important as it dictates the type of bearing that will fit your frame. Make sure to check with your local store before buying your bottom bracket to make sure you get the right one for your ride.