Theory

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...

The Theory Adirondack Bars are a great addition to the bike life scene. The multi butted and heat treated for superior strength. 8.25" x 33.5" We...

Please note price is for cups only, if you need the full bottom bracket kit it can be found here.

The Theory American Bottom Bracket Kit includes two color matched american bottom bracket cups, matching colored cone spacers, two precision sealed...

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

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°

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

Theory Crank Arm Pinch Bolts Sold as a pair  

The Theory Data Grip feature a classic mushroom style design for comfort and durability. 155mm in length to accommodate today's super wide bars.

The Theory Downtown 2 Bolt Railed Seatpost is an aluminum post that uses a two bolt design. Nothing overly fancy, just a workhorse looking to hold ...

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 Fork Compression Bolt M24

6" x 2"

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...

The Theory Method Tires are a great addition to the big BMX game with its refined design that offers a fast and grippy tire that wont break the bank.

The Theory Method Tires are a great addition to the big BMX game with its refined design that offers a fast and grippy tire that wont break the bank.

How are we going to see that work if your slippin' off the pegs? Don't worry Theory has you covered with pre-cut hassle free installation grip for ...

The Theory Pivotal Post is your basic pivotal post. Functions as it should, and comes in at a price that won't make you cry. Works best with tradit...