BMX Bike Parts

The Theory 1-1/8" Internal (Semi-Integrated) Headset work great as a replacement for bikes like the SE So Cal Flyer.  1-1/8" Sealed cartridge bear...

The Theory 3/8" Axle for SE Cassette will fit any single speed V-Brake bike like Big Rippers, Big Flyers, Blocks Flyer, etc. Shoulder to shoulder:...

The classic 410 chain has everything you need in a basic chain. 1/2"x1/8" 100 Links

Thicker side plates and riveted pins means the 510 chain can take some serious abuse. 1/2"x1/8" 100 Links

The Theory 8-Spline Spindles are a great replacement for any stock 8-spline spindle that may have unfortunately bit the dust. Theory has even taken...

Theory Axle Nuts Aluminum construction 17mm hex 26tpi

 Theory Bond Top Load Stem is made of cold forged 6061 aluminum with a 50mm reach. 

The Theory Bottom Bracket Spacers come in both 19mm and 22mm to work with most styles of BMX Crank spindles out on the market.Includes:(2) .6mm | (...

The Theory Bypass Bars are a 2-piece chromoly construction with a basic geometry that anyone can get used to. Width: 29.5" Upsweep: 2° Backsweep: 12°

Theory Cog (2.3mm Shimano Spec)  

The Theory Conserve Cranks are traditional 3 piece style made from a durable chromoly. The Conserve cranks use a 19mm 8 spline 135mm spindle. Great...

The Theory Conserve Cranks (Bike Life Version), are made from the same durable chromoly construction as the normal version, but instead come with a...

The Theory Conversion Headset turns a non integrated 1-1/8" headtube frame into an integrated one with this kit. This kit includes everything you n...

Theory Crank Arm Pinch Bolts Sold as a pair  

The Theory Data grips use a classic and comfortable mushroom style pattern. 150mm in length to work with today's wider bars. 

Theory Elevate 29" Forks Someone had to eventually bring another decent option to the 29" wheel game, and Theory did just that. The Elevate Fork is...

Theory Elevate 29" Forks (With Disc Mount) Someone had to eventually bring another decent option to the 29" wheel game, and Theory did just that. T...

Theory Fork Compression Bolt M24

The Theory Grip Stop are a simple machined aluminum clamp that keeps your grip in place. What you see is what you get.  SOLD INDIVIDUALLY 

Theory Headset Spacer Kit Aluminum Kit includes 3 spacers: (1)2mm , (1)5mm, and (1)10mm Fits 1-1/8" steer tubes

Theory Integrated Headset Sealed cartridge bearings 10mm dust cover

The Theory Median Pedals are a combination of thermoplastic bodies with removable steel pins. The removable pins are perfect for utilizing one side...