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How do I know what crankset to buy?

Writer Sarah Cherry

Cranks come in a range of sizes, most commonly from 165mm to 190mm, and ideal crank length is often determined by three factors: your height, your cycling discipline and your personal preferences. If you change your crank length, it will change how it feels to pedal your bike, and it may change your fit on your bike.

How do I know what size crankset to get?

Crank length is measured from the centre of the bottom bracket axle to the centre of the pedal axle. If you're not sure what length the cranks on your bike are, the quickest way of finding out is typically to just look at the backside of your cranks, just below the pedal axle.

How do I know if my crankset is compatible?

In most cases three-and two-piece cranksets are compatible with the same bottom brackets so long as the axle is the same diameter. They are commonly used in conjunction with the mid-style bottom bracket standard. One-piece: This is where the axle and crank arms are a single piece of steel.

How do I choose a crankset for my teeth?

The larger chainring gives you bigger, harder to turn gears that move you further per pedal revolution – so it's suitable for higher speeds – while the smaller chainring gives you gears that are easier to turn but move you a shorter distance per pedal revolution – so it's suitable for lower speeds, including riding ...

Do all cranksets fit all bottom brackets?

Crankset compatibility

In general terms, most cranksets can be fitted to a variety of bottom bracket shells, though much of this compatibility depends upon the availability of suitable hardware (see next section). Any incompatibilities that do arise are often related to the length and/or diameter of the crank axle.

16 related questions found

Are Shimano cranks interchangeable?

Shimano road cranks are interchangeable between other component levels that utilize the dual pinch bolt. Nearly all pinch-bolt style Shimano road cranks are able to be interchanged in equivalent lengths.

What do crankset numbers mean?

The numbers on the chainrings simply refer to the number of teeth on each chainring. A standard crankset will have the 53 and 39 tooth rings (obviously the 53 tooth ring is the large one and the 39 tooth one is the small one), while a compact crankset typically has 50 and 34 tooth rings.

What gear should I use on a flat road?

High Gear. This one is great for descending, accelerating, or for use when you want to go nice and fast on a flat road. In a high gear, you travel a long way for each turn of the pedal.

What is the difference between a compact crankset and standard?

A compact crank refers to a road bike crankset with relatively smaller chainrings that can make pedaling easier. While 'standard' cranks come with a 53-tooth large chainring and a 39-tooth small ring, compact cranks usually feature 50- and 34-tooth rings.

Are crank arms interchangeable?

Cranksets are not always interchangeable. Every crank is designed to work with a specific bottom bracket. Even if the cranks use the same interface (octalink, square taper, or hollow tech), switching them between bike brands or even models of the same brand is hard.

Can you use a SRAM crankset with Shimano bottom bracket?

Higher-end SRAM cranks demand a SRAM bottom bracket for secure installation and optimal performance. Thus, they aren't compatible with Shimano bottom brackets.

Will shorter cranks help my knees?

Pain is relieved. Just by installing shorter crank arms, without any other adjustment, the knee at maximum flexion is lowered by 7.5 mm. That difference provides approximately 3° to 4° of relief.

What is the difference between 170mm and 175mm cranks?

Macdermid found that riders reached their peak power nearly 1 second quicker on 170mm cranks than they did on 175mm cranks. That means shorter cranks give riders better acceleration, which can make a difference when passing other riders or trying to clean an obstacle.

Does crank length make a difference?

Choosing the length of the bike cranks has always been an interesting topic. In fact, the correct crank length can improve both the biomechanical performance of the pedal stroke and reduce the risk of injury.

Should you change gears while pedaling?

Shifting your gears while standing still stretches the cables and strains the derailleurs. Remember, you have to be pedaling before the bike will change gears.

Which gear on a bike is easiest?

Low Gear = Easy = Good for Climbing: The “low” gear on your bike is the smallest chain ring in the front and the largest cog on your cassette (rear gears). In this position, the pedaling will be the easiest and you'll be able to pedal uphill with the smallest amount of resistance.

When should you shift gears?

Generally, you want to shift gears when your car reaches 2,500-3,000 RPM. Eventually, you will know when to shift by sound and feel.

What does 50 34 crankset mean?

Standard Setup. Currently, the most common gearing setup on new road bikes is a 50/34 chainset with an 11-28 cassette. This means that the big and small chainring have 50 and 34 teeth, respectively, and the cassette's smallest cog has 11 teeth and its largest cog has 28 teeth.

What gear should my bike be in?

Low Gears, Middle Gears, High Gears

There are three types of gear; low gear, middle gear, and high gear. For riding on flat roads, it is recommended to use the middle gear. It is a common choice among bikers as it helps you reduce pressure from your feet onto the pedals.

How many gears should a road bike have?

A road bike will have either a triple, double or compact crankset. This refers to the number and size of chainrings (located by the pedals). A triple crankset has 3 chainrings; it is often paired with a 9-speed cassette on the rear wheel to give it a total of 27 gears.

Are bike cranks universal?

Many chainrings are not compatible across different brands or even across different models for any given brand. Cranksets attach to a frame via bottom bracket, and there are many different types of bottom brackets.

How do I know what size bottom bracket to buy?

To find out the size of bottom bracket needed, measure the inside of the bottom bracket shell in your frame, it will be 73mm, 70mm or 68mm. Some older frames may have Italian threaded bottom brackets, instead of the more modern English.

Do I need to change bottom bracket if I change crankset?

To answer your question specifically, yes cranksets require a specific bottom bracket, especially so the new offerings from SRAM and Shimano and others.