Crankset Buying Guide

The Crankset sits at the heart of the bike and comprises a couple of different components, namely the Crank Arm and the Chainring. This post has been created to answer several common questions about Cranksets. Although this part may be simple in its operation and purpose, there are many variations, making it tricky to choose the right crankset for your requirements. In the simplest possible terms, though, the crankset is the bike's parts that propel the bike forward, harnessing the power of your pedalling.

What Is A Crankset?

The formula stays the same regardless of the type of bike a crankset is on. There are two crank arms which are connected via an axle. Modern cranks have this axle built into the crank arms and passed through the bike's bottom bracket. Older cranksets have the axle as part of the bottom bracket, not the crankset.

What Are Cranksets Made From?

What cranksets are made from will vary depending upon the bike's age, the bike's cost, and the bike's purpose; on race bikes and mountain bikes you can expect to find carbon fibre cranksets, alloy cranksets on mid-range road bikes and mountain bikes - and steel cranksets on BMX and older road and mountain bikes.

Crankset Length?

One of the biggest determining factors in what crankset to purchase for your bike is the crankset length you require. Most Road and Mountain Bike Cranks are 170-175mm long. There are however a range of different crankset lengths, which may suit shorter or taller riders - measurements available sit between 160-180mm. Mountain Bike Riders who ride a lot of rough terrains will typically use a shorter crankset, which provides greater ground clearance over objects, especially in downhill racing and similar disciplines.

Chainrings Guide

Chainrings allow the chain to transfer power to the rear wheel. The chainring is the cog on which the chain links operate, and chainrings have teeth representing different gearing. Although it’s possible to buy high-end chainrings which have been made from carbon fibre, they are typically made from alloy.

There can be multiple chainrings, but many bike manufacturers have now largely switched to a single chainring, so the chainrings are directly mounted.

MTB Crankset Guide

Mountain Bike Chainsets in recent years has gone from an industry standard of having three chainrings to running a single chainring - although triple and double rings can still be found on some entry-level mountain bikes. Single chainrings are popular today because of their simplicity and increased chain retention.

Although almost all chainrings are now single chainrings on mountain bikes - there are still differences in design. Cranksets which are designed for cross-country mountain biking will be more lightweight than cranksets designed to absorb the impacts of downhill mountain biking, with its jumps and obstacles. So different mountain bikes require different cranksets.

One of the biggest developments in the world of MTB Cranksets is the shift towards the direct mount, mountain bike chainrings. Traditionally, cranks are mounted with bolts - although direct mount chainrings do not require these bolts, making it lighter and easier to maintain.

Road BIke Crankset Guide

An increase in the number of required gears on road bikes usually sees most riders favour a double chainset. A happy medium, also known as a semi-compact - is commonplace - running 52/36. This effectively closes the gap between compact gears and faster standard gears - it makes a full spread of gears within reach allowing easier and faster climbing.

Road Bike Cranks are typically between 170mm and 175mm in length, but the full range spans from 160mm to 180mm to cover different leg lengths and cadence requirements. Again, most road bike cranksets are alloy - but carbon fibre versions are available for those looking for ultimate weight-saving performance.