We put both aluminium and carbon sets to the test
Looking for advice on the best mountain bike cranks? You’ve landed on the right page. Here’s our experience and knowledge of single ring MTB cranks.
Now that the front mech is dead (hurrah!) we only feature single ring cranks in this guide. If you’re looking for a multiple chainring setup, you’re out of luck. Sorry!
Many riders with entry level bikes are thinking about converting their triple or double ring setups to a single ring but why all the fuss over 1x in the first place?
Losing gears may seem like a backwards step, but upgrading to a 1x crankset allows you to eliminate the front derailleur and all the associated weight, unreliability and attendant hassles. A narrow/wide chainring can put an end to chain loss, too. And it’ll save a ton of weight — the front mech, shifter and cable can add up to 450g (nearly a pound).
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There are some secondary benefits too — more clearance round the bottom bracket area, less maintenance as you have one less cable to look after and it declutters the handlebar.
These cranksets are yet to feature heavily on entry-level bikes because they go hand-in-hand with wide-range cassettes, and that’s where the money is, but affordable aluminium 1x cranksets are readily available aftermarket.
Is carbon worth it?
Once you’ve splashed the cash on a new trail bike one of the easiest, although not always the cheapest, ways of saving weight is to invest in some carbon components. The biggest savings can be had with the wheels but carbon handlebars and cranks can also shed the grams and, in the case of the latter, also boost pedalling stiffness.
As you can see from the prices, fronting up for a carbon crank is not an insignificant investment but Truvativ is offering a more affordable option in the form of the Descendent Carbon. This crank also runs on a traditional 24mm steel spindle, where as the two top-end cranks use stiffer 30mm alloy spindles. So the obvious question is are the top-end carbon cranks stiffer, lighter and more durable or is the budget route the one to follow?
We think the crank market is split between either whatever aluminium crank is in the sales at the best knockdown price (typically go with Shimano in this instance) or what is the best all-round carbon crankset, regardless of whether it’s in the sales or not. As such, this buyer’s guide reflects this opinion.
Having said that, we also feature a couple of aluminium cranks from alt brands (DMR and Hope) for those searching for a bombproof, Brit-designed setup.
Understanding the best mountain bike cranks
The traditional crank length on a mountain bike is 175mm but 165, 170, and 180mm cranks are also sometimes available. Shorter cranks offer better pedal clearance and work best for riders with short legs. Longer cranks offer more leverage and are good for riders with longer legs.
The alternating thick and thin teeth on a narrow/wide chainring interlock with the male and female links on the chain to provide more secure engagement and lessen the risk of chain loss. You can use any single ring with nine, 10 or 11-speed gearing and a Shimano or a SRAM drivetrain.
AKA bolt circle diameter. This is the diameter of a circle drawn through the bolts holding the chainring onto the spider. The common size for a triple crankset is 104mm, but there is different diameter for double cranksets and even some custom BCDs, such as that used for SRAM’s XX1 cranks.
Not all cranks come with a BB, so you’ll need to budget for that. And some cranks are offered with different diameter spindles, so it’s important to get the right size for your bike. If your bike has a standard threaded BB you’ll need a crank with a 24mm diameter axle. If it’s oversized you’ll need a BB30 crank with a 30mm spindle.
Forging produces the stiffest and strongest aluminium because it aligns the grain structure of the material. Hollow forging is even better, but it’s a more complex technique and is therefore notably more expensive.
These little covers protect the most fragile part of the arm from impact damage — essential on carbon cranks. They’re also available separately (from Race Face, SRAM and Zefal) for under a tenner.
If you’ve spent £600 on a carbon crank the last thing you want is for it to look tatty after two or three rides. Most carbon cranks come with clear tape on the arms to reduce wear and tear from foot rub. It doesn’t always look pretty but it can be replaced once it wears off.
Direct mount chainring
The standard method of attaching a chainring is to mount it to a spider, which is either part of the crank or bolted on. Direct-mount means eliminating the spider and bolting the ring directly to the crank arm, saving around 80g. The downside is once the ring wears out the whole thing needs replacing. And direct-mount chainrings do cost more.
Best mountain bike cranks: reviews
In price order, here are our favourite mountain bike cranks…
mbr review: “Offers fantastic performance and reliability and really does look stunning. After months of use through winter and into summer, our Hope crankset has been faultless. The extra stiffness of the 30mm spindle, and the solid, forged and CNC’d arms, is immediately apparent and very welcome. You’ll need to add in a chainring and bottom bracket — both are sold separately.”
mbr review: “With massive hollow-forged arms, an oversized 30mm axle and reasonable system weight of 784g, DMR’s AXE crank aims to be both light enough for trail use and tough enough for downhill abuse. For £240 you get all the parts you need to get you up and running but if you want to source your own BB and chainring, you can mix and match to suit. The crankset itself costs just £139.99.”
Truvativ Descendant Carbon
mbr review: “The Truvativ Descendant Carbon is a great first step on the carbon crank ladder; factor in £80 worth of chainring and, it’s actually more of a bargain. The X-sync 2 ring is easily the best thing about this crankset. It’s only when we back-to-backed the cranks that we noticed how much smoother it was compared to the Race Face and Praxis rings. Even with the chain at an extreme angle, there was less chain noise and it seemed to peal off with bottom of the ring much easier, which really helps when riding in wet and sticky conditions.”
Race Face Next SL G4
mbr review: “In terms of power to weight the Race Face Next SL G4 really is a superb – it’s also silly light, sensibly stiff and cheaper than other carbon cranks. Despite the Race Face crankset being lighter than the Praxis Lyft (see below) it’s equally as stiff with a positive feel under the pedal. Like most carbon cranks, there’s a damped feel when riding rocky or hard packed surfaces but it’s still incredibly responsive when charging up a climb.”
SRAM X01 Eagle DUB
mbr review: “For more stiffness and weight saving, SRAM’s new aluminium axle is a hair under 29mm, a big leap up from the older (steel) 24mm one and closer to an oversized 30mm spindle. The new axle’s extra mm of space (over 30mm designs) sounds minimal, but it allowed engineers to better seal the BB against contamination and ensure lifespan is at least as good as the older GXP with its bigger balls. The latest chainsets are compatible with all current frame sizes with the correct BB too.”
Praxis Works Lyft
mbr review: “The Lyft is incredible responsive when stepping on the gas but at the same time has a nice damped feel when you’re slamming through rough stuff. Praxis Works has done an excellent job on the Lyft crank, it’s stiff, lightweight and top quality and it should stay that way too with scratch resistant helicopter tape and crank boots included in the box”
Best mountain bike cranks: verdict
A crankset, especially one with a single ring, is one of the few components on a bike that you can fit without having to worry too much about compatibility.
Best mountain bike cranks aluminium: Hope Spiderless.
Best mountain bike cranks carbon: Race Face Next SL G4.