Mountain bike cranksets are very important when it comes to the proper functioning of your MTB bike. With most cranksets having external type bottom brackets that have larger bearings, this makes them sturdier and stronger with a longer bearing life. Let’s look at how they function and how you can choose the perfect set-up.
Mountain Bike Crankset FAQs
What is a crankset?
A mtb crankset (sometimes called a chainset) is the essential part of a bikes drivechain and is made up of a crank, bottom bracket and chainring. The mtb crank arms are where the pedals attach and range in size from 165mm to 180mm – the standard size is 175mm.
What types of cranksets are there?
They generally come single, double or triple crank wheels. The market has moved towards single crank wheels (1x) with Sram and Shimano producing 11/12 speed cassettes. Having a 1X mtb crankset means you are shedding all the weight of have a second derailleur and reducing the potential problems. A 1X MTB work with just the rear derailleur to change the gears.
What are Cranksets made of?
Mountain bike cranksets are made of steel, aluminum and carbon. Carbon MTB Cranks being the lightest and most expensive.
Who are the top Crankset Manufacturers?
Sram, Shimano, Truvativ, Hope DMR, Race face
Are carbon cranksets best?
Not necessarily. They are definitely lighter, but there are much cheaper MTB parts to change out first if you are looking to shed weight.
What is a DUB Crankset?
DUB stands for ‘durable unified bottom bracket. DUB technology was produced by Sram when they standardized their spindles to 28.99mm (not 30mm!!) across their range. They now have one spindle and four different bottom brackets (BB) that will fit most standard mountain bike frames.
MTB Crankset Test by Team Sauserwind
To carry out the mountain bike crankset reviews , we ensured all the products were tested by our writers. Having a combined 16 MTBs between us, this was not difficult. To rate these MTB cranksets, we specifically looked at the following.
- Crankset Price
- How smoothly the cranks rotated
- Material used for crankset manufacturing
- Crankset weight
Here’s some of the best MTB cranksets on the market in 2019.
SRAM GX 1000 GXP X-Sync Crankset
The SRAM GX 1000 X-sync crankset is built to provide you and your bike a whole new level of durability in any terrain. The chainrings are specifically designed with mud-clearing recesses to increase your bike’s performance level.
GX gives you personalized options gear choices and ranges to match your riding style. The finish is great and it’s built with an attractive design for both convenience and aesthetic purposes. This crankset is very durable so it will be able to stay strong through multiple uses in any terrain.
- Incredibly easy to install
- Boost 148 compatible
- Great design for convenience and style
- Light MTB crankset
- Built a bit heavy
Truvativ Descendant C Eagle Dub Crankset
Lightest mountain bike crankset on test
The Truvatic Descendant C Eagle Dub crankset is built with a spindle design that gives you a whole new level of capability for your bike. This MTB crankset will give you the capability of both forward and backward compatibility.
It is designed with DUB technology and carbon construction for lightweight durability. The carbon construction is light enough for cross country racing while still giving your bike a high enough level of durability for other heavier bike riding purposes.
- Provides sealing against contamination
- Fits all major bottom bracket standards
- Will remain durable even when coming in contact with a hard surface
- More expensive than other carbon MTB cranksets
FSA SL-K Modular Adventure 386EVO Crank
The FSA SL-K Modular Adventure 386EVO crankset will provide your bike with excellent coverage for gravel, adventure, or road use. It can fit in a variety of frames to accommodate your bike.
46/30T chainrings are included with this purchase of this crankset. It is able to fit the Shimano and SRAM 10-11 speed system and hollow carbon fiber arms with a UD finish.
- Good to use for mountain terrain
- Built with a forged AL7050 BB386EVO spindle
- Made with the latest FSA crankset technology
- Priced quite expensively
Shimano SLX FC-M7000-1 Cranks
best 1x crankset on test
Aside from a slight weight penalty that comes with this product, the Shimano SLX FC-M7000-1 crankset will aim to provide you with the same high-quality service as other equally high-quality products.
These cranks were perfectly designed and modified to stay strong through any type of terrain your bike endures. Charging bolts are included with the purchase of this crankset, and it can be used for a Shimano 10 speed cassette. It is designed for easy installation even for those who have minimal knowledge of fixing bikes.
- Good price for its performance
- Durable and lightweight
- Charging bolts are included
- Does not come with a bottom bracket
Crank Only – Add Chainrings and BB Separately
Shimano XT FC-M8000-1 Cranks
[Cranks only, order chainring+ BB as an addition]
The Shimano XT FC-M8000-1 Cranks will provide your bike with more stability than ever before. These cranks are built out of aluminum and will decrease the weight and bearing drag. They will help your bike work smoothly through more muddy road conditions.
The asymmetrical bolt pattern that is designed for this type of crank will give your bike a greater level of responsiveness and stability. It does so by placing the strength spots where the most pedal force is applied. It is built with Hollowtech II technology and will allow you to have a variety of bike type and riding style options.
These bike cranks are designed to give you a smoother riding experience while helping you keep your bike stable through more rugged terrain.
Recommended Chainring Pairing – Shimano SLX M7000 1X chainring
- Compatible with a single chainring
- Better sealing and smoother rotation
- Hollowtech II technology gives you more riding style options
- May not function as a 1x crank
3 Chainring Crankset Options
SHIMANO M361 Hybrid Crankset 3 Chainring (Black)
Shimano’s 3 chainring chainset is still lightweight at only 900g. This crankset is square bottom bracket compatible and not included.
- 175mm crank arm length
- Comes with 3 chainrings - 42/32/22
- Comes with a chainguard
- Square bottom bracket compatible
Shimano Altus M311 7/8s 42x32x22 175mm 3 Chainring Set
This does not come with a bottom bracket so make sure you buy a compatible product separately. The chainrings on the Altus are fixed and cannot be removed.
- Shimano Altus M311 7/8-Speed 175mm 22/32/42t Square Crankset Chainguard BLK
SRAM S600 3 Chainring Crankset
This is an exceptionally smooth crankset with 3 chainrings offer 8/9 speed. The Spam S600 weighs 825g and has a standard 175 mm arm.
Again the bottom bracket is not included.
- Sram S600 triple chainsets
- 42-32-22 teeth chainrings with 175mm cranks
- Made of forged alloy
- Available in pitch black colour
- Size: Square taper. 8 speed
How a Mountain Bike Crankset Functions
MTB cranksets differ in crank length, the number of chainrings and the bottom bracket (BB) type.
MTB crank arms are usually 175mm long. Riders who have longer or shorter legs will feel more comfortable on cranks aligning with their leg length. 165mm to 180mm is ideal for different leg lengths, but it would be best to determine your crank length in relation to your leg length.
Type of bottom bracket (BB)
This is the engine room of any MTB crankset and is located at the junction of your frame’s seat- and down-tubes. It comprises two bearings – one at either side where your pedal axle is located, allowing the chainset and pedals to spin.
The bottom bracket assembly may also comprise spacers and lockrings among other parts. All these depend on the type and design.
If you have a good-quality BB which has been correctly installed, it should last you for years. Ensure that your BB is secure and in good condition. Replace or upgrade your BB with models that fit with your bike type.
Depending on how you want to use them, MTB chainsets normally use either one, two or three rings.
-Direct Mount V Spider Chainrings
Usually chainrings attach to a spider which forms part of the crank, but recently direct mount (DM) chainrings have become popular. Direct mount chainrings attached directly to the crank so you don’t need the spider, saving weight. Spider chainrings attach with either 4 or 5 bolts.
The chainrings on good cranksets tend to have teeth which alternate in thickness, this make the system more securing and help prevent your chain coming off. Most common single chainrings are 38T + and the most common double chainring has 42T on the inner and 52T on the outer.
Guide for Picking the Right Crankset
The Crank arm’s length
MTB Crank arm lengths vary from 165-180mm and have 5mm increments. While the standard length of mountain bikes is usually 175mm on bikes, the smaller frames and those used by women might be shorter and around 165mm. The long arms are ideal for downhill and the short arms for uphill.
The shorter MTB cranks are the best alternative if you have short legs while the long ones are great if you have long legs. The best would be to try out different sizes to see which one is comfortable using a professional fitting to determine the perfect length.
Below is a chart giving you the perfect crank arm length to your height.
There are two connected parts in every crank set which are the crank arms and the chain rings. Each might be made of a different material, though they mostly include aluminum alloy, Chromoly steel, carbon fiber, titanium among others. Check your other components to determine the right materials.
Carbon cranks are expensive, lighter and stiffer compared to steel which is heavier and cheap. If you decide to go for steel, use Chromoly steel which is more durable compared to other forms of steel. Aluminum and titanium are also great though titanium is more expensive and less common.
Consider the chain rings
The chain rings and the gear ratios go hand in hand with the gear ratio, determining the pressure you put to turn the wheels. The ratio is determined by taking into account the number on the rear cog to the number of teeth on the front chain ring.
A higher gearing has a bigger front chain ring to smaller rear cogs. It needs more speed and power and, thus, is ideal for downhill and flats. A lower gearing has a smaller front chainring and a bigger rear cog. It generates less power and speed and is ideal for hard ascents.
We recommend checking the number of chainrings and the sizes and comparison with the rear cog before buying a MTB crankset.
-How to choose a direct mount chainring
Check out this video from our partners which teaches you all about off set chainrings
Style of the bottom bracket
Bottom brackets come in various styles and their compatibility differ since bottom brackets of different sizes have different frames. Determine your frame bottom bracket size before buying one.
MTB Crankset Care and Maintenance
You must regularly inspect your crank arms and chain rings and ensure that they are working well and in good physical condition. Check if there are any dents or any form of damage.
To see if they function well, grab either crank arm (not the pedal) and rotate it back and forth. If they move, it might be that the bearings are either damaged or crank bolts are loose and need to be adjusted.
A bend in your crank arm or pedal can be felt during pedaling. Remove the pedal, and spin it.
A pedal that doesn’t spin smoothly is damaged and you need to replace it. In short, your bike needs servicing so take it to a bike shop for servicing.
Always keep your bike clean and as dry as possible. Clean your bike to remove any dirt and grime which might affect your bike’s performance by washing it after each ride. You can use a toothbrush or a stiff brush and solvent. Avoid spraying water directly on the bearing.
Installing Cranks and Reinstalling Pedals
Place the right MTB crank onto the spindle in the 6 o’clock position. Slide the left crank onto the spindle in the 12 o’clock position, then you will be able to screw the new crank bolt into its socket with an Allen key.
If applicable, replace the cap and tighten the pinch bolts and then place the pedals back onto the crank arms.
Buying a MTB Crankset Conclusion
Now that you are aware of how to remove and install crank set and have information on some of the best crank set products, you will be able to have the best quality crank set for your mountain bike. Remember to always check what type of crank system your bike has so you will be able to buy the right product and install it correctly.
Further MTB Crankset Resources
Boost Crankset – Understanding Chainline for Optimal 1x Conversions
Video guide to Sram DUB technology
Image source: Jenson USA, Sram