[GKelley]

I'm shopping for some shorter cranks and figure I might as well look into an upgrade while I'm at it. My current cranks are the Truvativ Descendant Dub 6k set.

I'm either looking to go ahead and get a 7k series aluminum crank, or maybe even trying a carbon crank.

Is carbon even worth it? Will I feel a difference on the trail? Or are carbon cranks just for bling and weight savings?

EDIT: I should mention I am not the smoothest rider out there, so durability is an important factor.

 

[WHALENARD]

I "feel" their stiffness. Maybe moreso than any other part next to rims.

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[TwoTone]

I'm not afraid of carbon, have tons of it on my bike. Cranks is the one place it's not worth it to me.
You can get AL cranks that as light as carbon. My Hollowgram SiSl2 are 460g with Wolftooth Camo spider and 32t oval.
I have a set of Rotor Kapic coming from Germany. Not as light but a good balance between price, weight and it's not carbon.

 

[Suns_PSD]

Maybe you can feel the extra rigidity, but the weight savings is worth more than that. Weight savings isn't just a fashion choice or something and there is a solid 1/3# rotating to save there.
That said, CF cranks are a great choice for XC trail riding but I'd only consider Eewings for AM riding just because I've broken CF cranks.

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[Thoreau]

My 2018 carbon stumpy came with one of those truvativ descendant (non boost) cranksets. after splurging on axs eagle and all the xx1 bits, i came across a deal on a set of x01 cranks, so I figured why not...

i honestly have not once noticed any difference between the old alloy cranks and the shiny x01 carbons. I know they're lighter, supposedly stiffer, etc. but in real world use that was the most intangible upgrade I've ever made. I'd still do it again just because I like shiny things and even if I can't feel it, weight savings make the flabby parts of me happy. It also forced me to switch out the original pf30 BB for a dub compatible model, which in turn came in handy when i changed bikes last year.

I've known more than a few others who have upgraded to carbon cranks and feel the same way (most of them far more expereienced riders than me.)

No regrets regarding durability though. I slapped on the typical crank end boots on day 1 and despite running my Enduro flip chip in the low setting, and being a fairly crapy rider, the chunky az trails have yet to even destroy the cranks, or even scratch them.

 

[Amt0571]

Unpopular opinion: carbon isn't generally worth it. On anything. Specially on mountain bikes. Specially on mountain bike cranks.

 

[p0is0n0ak]

I "feel" their stiffness. Maybe more so than any other part next to rims.

I'll second this sentiment. I find Al cranks to be overly flexy and harsh for my tastes. I'm a bigger guy who can put down decent power, so the flex is very noticeable. I also have a disdain for the trail feedback that comes through Al, preferring the ride feel of carbon.

 

[WHALENARD]

I'll second this sentiment. I find Al cranks to be overly flexy and harsh for my tastes. I'm a bigger guy who can put down decent power, so the flex is very noticeable. I also have a disdain for the trail feedback that comes through Al, preferring the ride feel of carbon.

Ditto all that. As a long time weight lifter I hover at right around 235#'s at my peak summer fitness. My first set of carbon cranks was revelatory in the flexing and negative feedback I was getting through aluminum cranks.

Furthermore, ovalizing the pedal insert on aluminum cranks was a common occurrence for me at 2 to 3 seasons of use, even on big cranks like Atlas. I've yet to mangle a set of XO1's.

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[itsky]

Interesting, in a recent review in Enduro magazine, they were saying the new AL Sram GX crank was stiffer than the X01 Carbon.

 

[LMN]

With Carbon cranks you will always have shiny new cranks that really pop. With Aluminum cranks you transfer them from bike to bike and they will look dull and worn.

 

[Ogre]

I have mixed luck with carbon cranks. Have a pair of 7 year old X0 cranks which I love, and a pair of Raceface carbon cranks that gave out, got warranteed, then failed again.

I'm not sure I'm sold on it, definitely not when the focus is primarily on dropping weight. I've never noticed flex in AL, but never really thought about it either. I'll have to think on that.

 

[Skrool]

I think your question should better be : What is the benefit of Aluminum over Carbon. The answer is : Aluminum cranks NEVER give you problems, and, are nearly just as light. Every single pair of carbon cranks I tried on my MTB failed in less than a single season. After the 3rd pair I went back to Aluminum and have never looked back. Aluminum cranks simply work, never fail, and never produce issues....and...are cheaper.

 

[GKelley]

Interesting insights so far. I appreciate all your responses.

 

[Ogre]

I think your question should better be : What is the benefit of Aluminum over Carbon. The answer is : Aluminum cranks NEVER give you problems, and, are nearly just as light. Every single pair of carbon cranks I tried on my MTB failed in less than a single season. After the 3rd pair I went back to Aluminum and have never looked back. Aluminum cranks simply work, never fail, and never produce issues....and...are cheaper.

Curious now because I had a pair fail too. Which brand of cranks?

 

[Harold]

I consider cranks to be a pretty low-value upgrade above a solid alu crankset. I'm not saying the benefits aren't there. Just that the cost to get those benefits starts going up fast.

I wouldn't argue if someone gave me an eewings crankset, though (which is exactly what happened to a friend of mine a couple years ago - lucky bastard).

 

[Jayem]

I think your question should better be : What is the benefit of Aluminum over Carbon. The answer is : Aluminum cranks NEVER give you problems,

 

[Ogre]

Crash Photo

I've had carbon cranks fail when I was just cruising with no associated taco'ed front tire.

The failure without contact with pavement is my bigger concern with cranks.

 

[dysfunction]

Once a wheel's capable of holding fish tacos... almost all other bets are off IMO

 

[Jayem]

I've had carbon cranks fail when I was just cruising with no associated taco'ed front tire.

The failure without contact with pavement is my bigger concern with cranks.

Yeah, but the claim that aluminum cranks NEVER give you problems is just as ridiculous as saying Race Face Next SL is durable. Plenty of people have pulled pedals out of aluminum cranks, bent cranks, had interface problems, etc.

IME, Race Face carbon cranks should not be used as an example of CF cranks. They have been systemically bad, while SRAM has managed to make a durable product IME. I've broken 3 sets of the RF and the SRAM stuff has held up amazing. This appears to be due to SRAM using a metal skeleton inside the crank, rather than pedal/axle inserts bonded blindly into carbon fiber with the RF stuff.

Hollow shimano cranks are generally a good value, but they keep changing their chainring mounting standards basically every year or so. There are other metal cranksets that are a good value. If you learn/research a bit about aluminum alloys, you'll see there is a difference between some of the lower end and higher end aluminum stuff.

 

[HerrKaLeu]

IMHO, a crank seems to be the most expensive and worst place to save weight unless your life depends on being on the podium. Low center of gravity. And when I look at my Al-cranks and see the battle scars, I'm glad it is not fragile. It looks like rocks don't move out of the way, no matter how often i hit them. Yes, carbon is strong for the design forces, but not for impacts.

Some people put protective sleeves over their Cf cranks. But they add weight.

This is just my personal opinion and thoughts. It is your money and you have to decide if the few gram are worth it. The above may not apply if you are a very good rider that coordinates crank position well to avoid rocks.

Crank is the one part I think I need to change at some point due to damage without actually crashing. So better not to put all my money in it.