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I've only noticed cheap road cranks flex. Like really cheap old square tapers on lowest end bikes.

Even a $80 slx crank is crazy stiff. I bought my x01 mostly because I wanted an x01 crank. I can't feel a difference between it and any Shimano crank, but the price was right and I wanted a cool crankset.

High end cranks are a pretty colossal waste of money.
 

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Elitest thrill junkie
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Yours is the first I've seen, now lets compared that to the how many reported for carbon cranks?
I have pictures (if you want to see them) of how badly I've beat on my X01/XX1 cranks DHing and enduro. Disclaimer, after about 5-6 years and 2 bikes, I eventually broke the XX1, slamming the pedal on a root on a ride, but I got my money's worth. I ram these things into rocks and all sorts of stuff and they are fine with it. They actually have a durable construction IMO and I'd take them over an aluminum crank that has been made effectively paper-thin.

We see the same thing with fat-bike wheels. There are a few aluminum rims that have enough cut-outs in their single-wall construction to be "as light" as some of the carbon-fiber ones, but the aluminum ones at the same weight have the consistency of soft cheese comparatively, at least to anyone who has experienced the carbon-fiber ones. For the extra material (not weight) I get double-wall construction and a much stronger and stiffer (never needs truing) setup.
 

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change is good
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Unpopular opinion: carbon isn't generally worth it. On anything. Specially on mountain bikes. Specially on mountain bike cranks.
Agree, mostly. I have to have a carbon 29er rear rim and a carbon handlebar.


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Elitest thrill junkie
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I have pictures (if you want to see them) of how badly I've beat on my X01/XX1 cranks DHing and enduro. Disclaimer, after about 5-6 years and 2 bikes, I eventually broke the XX1, slamming the pedal on a root on a ride, but I got my money's worth. I ram these things into rocks and all sorts of stuff and they are fine with it. They actually have a durable construction IMO and I'd take them over an aluminum crank that has been made effectively paper-thin.

We see the same thing with fat-bike wheels. There are a few aluminum rims that have enough cut-outs in their single-wall construction to be "as light" as some of the carbon-fiber ones, but the aluminum ones at the same weight have the consistency of soft cheese comparatively, at least to anyone who has experienced the carbon-fiber ones. For the extra material (not weight) I get double-wall construction and a much stronger and stiffer (never needs truing) setup.
And my point isn't that either one is necessarily better, but when you start claiming your paper-thin aluminum one that weighs as much as the CF one is "better"...um, no, I'll go with the "regular" aluminum crank with enough material to stand up to a few bashings, thank you.
 

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View attachment 1924748

Shimano XT far stiffer than SRAM XO carbon. 102 N of force for each mm of flex/deflection vs 78 N.

Stiffness-to-weight is another story though. Between cranks of similar weight, cranks with large hollow sections were stiffer. Lightning/SWorks has some of the best stiffness-to-weight. Heavier cranks are generally stiffer.

Upgrade worthiness here more dependent on riding style. If you prefer to plow and cruise with stability, comfort, smoothness, steady-turtle-like pacing, etc. over being active with agility, playfulness, thrills, rapid-accelerating-rabbit-like pacing, etc. then it's generally a waste to spend money on lightweight cranks. Carbon is generally a compromise people make for the sake of lowering weight.
More fake news

I’ve been a XT fan boy for years and my XOs feel stiffer.


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change is good
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I remember when we heard the issue was solved with the G4's, then it wasn't.
Just maybe they got it right this time? No worth the risk to me for no gain. There's a reason carbon frames have been getting heavier.

Just a refresher since a sample size of 3 is meaningless.

A single shop warranty box: View attachment 1924761
Not fake news. Race Face sucks. I don’t worry about my XOs breaking. But alloy is a better value by far.


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Agree, mostly. I have to have a carbon 29er rear rim and a carbon handlebar.


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Rims and handlebars are the other places where I wouldn't touch carbon with a flagpole, they're simply not worth it safety wise.

Spending a fortune to save a few grams in a component that won't tolerate forces for which it wasn't designed (impacts, mainly) on a mountain bike, seems like a joke to me.

My current mountain bike is one year old. I have not fallen even once with it, however, cranks already have some impacts from hitting rocks when climbing technical sections, and from flying rocks sent by the front wheel. The frame and rims also have a few impacts from gravel and rocks thrown by the tires.

I'd be comfortable on a carbon road bike, but not on a MTB. In any case, I still think it's not worth it even on the road.

My endurance road bike cost me 1099€. The only carbon parts it has are the fork and seatpost, and it weights 8.5kg even with hydraulic disc brakes. Meanwhile, a Canyon Endurace CF SL Disc 7.0 weights 8.39kg and costs 2099€ while being similarly equipped (105 vs Rival, DT Swiss E 1850 vs Mavic Ksyriums). Almost double the price. It's just a scam.
 

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Trail Ninja
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I didn't make an experiment, but I guess the flexing mainly comes from the spindle, am I wrong?
Models with the same axle but different arms measure very differently in stiffness, from around 55 N/mm to 105 N/mm.

Though, I'll note that NDS cranks that attach by spline and bolts tend to measure less stiff than the DS crank with a tight shrink-fit style of press-fit. S-Works/Lightning crank Hirth coupling had the least variation in stiffness between DS and NDS arms.
 

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Rims and handlebars are the other places where I wouldn't touch carbon with a flagpole, they're simply not worth it safety wise.
Agreed. I could barely make it through a two hour ride with carbon rims and bars without 1. my bike breaking and 2. a trip to the ER. Now that everything is aluminum and steel, I can finally get a workout.
 

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Yours is the first I've seen, now lets compared that to the how many reported for carbon cranks?
It is in fact a common problem. Hollowgram knows about it. Expained to me it was a bonding issue when glueing the 2 halves together. My Raceface carbons have 5k of heavy off road use and no failure yet. knocks on wood
 

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Holy crap. Is that crank press-fit from two halves? No wonder it broke. No part of that assembly is any stronger than the half of what it should be.
It is. Standard for Hollowgrams. They knew about the bonding failure. Despite such they don't warranty them after 12 months
 

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Agreed. I could barely make it through a two hour ride with carbon rims and bars without 1. my bike breaking and 2. a trip to the ER. Now that everything is aluminum and steel, I can finally get a workout.
Carbon works well until you hit it the wrong way. Which, as you surely know, never happens on mountain bikes.

I'm going to leave for another day the crappy manufacturing of everything bike-related, but specially everything carbon.
 

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I recently got these e*13 LG1 carbon cranks on a new bike. I hope they're durable. They say they're DH-rated.

 
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