Crank Stiffness, carbon vs. aluminum

Forums Mountain Bike Forum Crank Stiffness, carbon vs. aluminum


Viewing 2 reply threads
  • Author
    • #585611

      Searching the internet for credible tests of carbon vs. aluminum cranks for stiffness is hard to come by.   I just find a lot of repeated marketing hype.  Does anyone know of any tests where actual stiffness measurements were reported?

      My personal experience is that I’ve put a lot of XC miles on both high quality carbon and aluminum cranks.  Having broken two carbon cranks at the pedal inserts I’m going back to aluminum now, which I have never broken.  This is in regards to durability.

      The obvious difference is weight, where my Next SLs (carbon) are about 160 grams lighter than my Turbines (aluminum).   Even as a self-confessed weight weenie, I no long care about this weight located low and in the center of the frame if it costs me durability.  And the expense wouldn’t bother me if they lasted at least a few years.  My carbon cranks failed after six months.   I’m concluding that making mtb cranks out of carbon with alloy pedal and crank inserts is a poor design.

      I have not been able to feel any difference in stiffness (on FS XC bikes) and I have no reason to believe the marketing hype that more expensive carbon cranks are any stiffer than say a $105 SRAM NX crank.   Does anyone know of any credible tests on this topic?

    • #585659

      There aren’t any.


      It’s pretty much what you describe. Carbon parts are cool. And light, and pricey. They definitely have their place. But if you’re a strong rider, carbon cranks don’t make a lot of sense. Very little gains, and failure is a real possibility (as you’ve experienced).

      I ride (road) with a guy who has tree trunks for legs. Strong rider/racer. He’s snapped carbon chainstays on two bikes so far. Just sayin’.

    • #585660

      Pfft! Plastic, no thankya. If I’ma droppin serious coin, Cane Creek Ti, *Mic Drop*

Viewing 2 reply threads

You must be logged in to reply to this topic.