NEED SOME HELP UNDERSTANDING BMX CRANKS?

BMX cranks have plenty of options and come in many different constructions, sizes and options. This may be daunting at first but it's not as complicated as it may seem. Use our handy guide below to find your perfect cranks and if you still have questions just get in touch and we will be happy to help.

Click below to check out our BMX drivetrain Buyers Guide video.

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CRANK ARM LENGTH

The length of the cranks arms from the spindle to the pedal. Any length will work on all bikes but there are a few things to consider; If you are purchasing a replacement crank for a child's BMX its best to measure what you are replacing and match accordingly, 10mm either way is acceptable.

If it’s for a full size BMX, the length will be personal preference of the rider. Standard lengths of cranks are 170-175mm which are great for all types of riding. Some street riders, especially those running 2 pegs at the back sometimes prefer shorter cranks for better heel clearance between their heel and peg.

SPINDLE DIAMETER / BEARING TYPE

99% of all freestyle BMX bikes now come with a standard Mid Bottom Bracket shell which makes frame compatibility easy. The only thing you need to get right is matching up the inner diameter of your BB with the spindle size on your crank. All our cranks have their spindle diameter listed in the specifications and you will need a BB to match - for instance a 22mm Spindle will require a 22mm Mid BB.

Note: That race frames and cranks typically use a Euro BB and are clearly marked as such.

SPROCKET TYPES

All of our standard sprockets will fit our cranks as they are supplied with the relevant spacers and simply bolt to the crank arm using the spindle bolt.

Alternatively we do also offer Spline drive sprockets which work only with 48spline spindle cranks and must match the size of the spindle - for example a 22mm Spindle must have a 22mm Spline drive sprocket.

Spline drive sprockets work with any 48 spline spindle crank but some spline drive specific cranks are also available which don't have a sprocket bolt for a cleaner look.

RHD / LHD

RHD / LHD or drive-side refers to what side of your bike your drive chain is situated. The standard on BMX bikes is on the right but there are options to run your drivetrain on the left.

The reasons for doing this is that if you grind on your right side there are some advantages to moving to LHD to prevent catching sprockets, chains and drivers when grinding. If you are looking to swap to LHD you will need LHD specific cranks and a LHD rear hub for this to work.

All our cranks are specified Right or Left hand drive in the specifications and many are compatible with either. Rear Hubs/Wheels on the other hand are typically specific to one drive side only.

GEARING

This refers to the relationship between the front sprocket and rear cog and determines how easy or hard it is to pedal. The standard gearing for full size Freestyle BMX bikes is 25t - 9t. However, there are some other popular combinations below. Obviously if you like it slighter harder to pedal, you can increase the size of the front sprocket - for example a 27t-9t.

25t-9t
28t-10t
30t-11t
33t-12t
36t-13t
44t-16t