Cranks

BMX Cranks Buyer’s Guide

Cranks are the metal arms that connect your pedals to your bottom bracket, which is the set of cups and bearings located inside your frame. Needless to say, cranks take a pretty serious beating from grinds, stalls, hard landings or straight up wear and tear, so they need to be built tough. Cranks come in nearly every color you can imagine, allowing for some personalization, and they are also a great place to save weight.

Things To Look For

As with any component, choosing the right set of cranks depends heavily on your riding style - the more aggressive you ride, the more robust your cranks have to be. Luckily, almost all cranks are sturdy enough to withstand some pretty serious riding. In fact, a good set of cranks will often outlast a frame. For that reason, it may be worth it to invest in some cranks that save weight, look good, and suit your style. It is also essential to know of the type of bottom bracket your BMX is equipped with in order to insure proper fit.

Types

There are four types of BMX cranksets to choose from: 3-piece, 2-piece, 1-piece, and race cranks. Most 2 and 3-piece cranksets are compatible with the same bottom brackets, so long as spindle diameter is consistent. Race bikes use a different style of cranks and bottom bracket, and are often made of aluminum, whereas freestyle cranks are made of either steel or chromoly.

3-Piece: This is the most common style of cranks on freestyle BMX bikes. They use two separate arms and a splined spindle, which is available in 8, 16, and 48 spline varieties.

2-Piece: Developed more recently than 3-piece cranks, the 2-piece design features a spindle that is integrated into one of the crankarms. Many companies offer both 2 and 3-piece cranksets.

1-Piece: These are most commonly found on children’s and entry-level BMX bikes. In this design, the spindle and both crank arms are all one piece. This type requires an American style bottom bracket.

Race Cranks: In order to save weight, race bikes use a different crank style that is more commonly found on mountain bikes. These cranks come in 2 and 3-piece designs, are made of aluminum or carbon fiber, and use Euro style bottom brackets.

Sizes

Crank sizing depends on two factors - the length of the crankarm, as measured from the center of the bottom bracket spindle to the center of the pedal spindle, and the diameter of the spindle. There are a plethora of available crank lengths ranging between 140 and 190 millimeters. However, most complete bikes come with either 170 or 175 mm cranks, and we’d suggest you stay close to that range. The two common crank spindle diameters are 19 and 22 millimeters, so make sure to check which one you have. Pedal spindle size is also a factor, but this is only a concern on children’s bikes, which have 1/2-inch spindles instead of the standard 9/16” size.

Materials

BMX freestyle cranks are made of either chromoly or steel. Higher quality cranks use chromoly because of the added strength. Race cranks are made of aluminum, and in some cases carbon fiber because they prioritize weight over strength.

Price Points

Cranksets range from around $10 for 1-piece cranks to $35-$400 for 2 or 3-piece designs. In the $35-$100 price range, there are many 3-piece cranksets available. They use either 6, 8 or 16 spline spindles, and crankarms are made of either steel or chromoly (chromoly cranks start at around $50). This price range offers good value and can sustain a considerable amount of abuse. Moving up to cranks ranging from $100 to $200, performance is emphasized with lighter and stronger designs coupled with the use of superior materials. These cranks come in both 2 and 3-piece designs, use stronger 4130 chromoly crankarms and 48 spline spindles to increase durability. Cranks in this price range are a great upgrade on most stock sets and are strong enough to withstand all levels of riding. The $200-$400 range cranksets use the same 48 spline 2 or 3-piece design as above, but incorporate more sophisticated manufacturing techniques and extremely lightweight parts. Cranks in this range are for riders seeking ultimate performance and will be a considerable upgrade on almost any stock BMX.

Product Reviews

Before buying, be sure to do your research and read product reviews. Reviews are a great way to find out specifics about a particular model, user impressions, and things to watch out for. After you’ve purchased a product and had enough time to thoroughly test it, we encourage you to leave a review for other people to see when they are researching bikes and parts on the web.

We hope you’ve found this information to be helpful. If you have a question that isn’t answered in this guide, our BMX forums are a great place to get advice from knowledgeable riders. Your local bike shop is also a great resource.