Carbon cranks vs. Aluminum


#1

Is it worth an extra $300? I’m looking at the Quarq Dzero Crankset so I can begin training with power. I like the looks of the carbon cranks better, but I’m wondering if the extra $300 would be better spent elsewhere…can anyone offer insights on this matter?
Thanks in advance!


#2

Lighter? More bling?


#3

I spent 4 years on aluminum crank arms and went to carbon in the past few months (using the same Dzero spider) and I prefer the carbon. It may be placebo, but the different in flex is noticeable to me, especially when out of the saddle.


#4

Are you using the quarq carbon cranks or something different? Do you just like the feel better or have you noticed a difference in performance?


#5

Yes, the Quarq carbon cranks. It’s difficult to say if there is an actual performance benefit, but I did recently set an all time 3min power pr in the offseason. Correlation != causation though.


#6

I’ve always wondered if a stiff crank on a “not so stiff” bike would help.

Like if you get your cranks 100% stiff maybe you’re just bending your bottom bracket more.

It almost seems like you need the whole system to be pretty rigid: shoes, pedal spindle, cranks, bottom bracket, bike…and then stem and handle bars while sprinting.

I’ve also never seen specialized advertise watt savings for stiffer things, which makes me think it’s a very small amount (< 1 watt) since I think if they could prove it saved 2-3 watts they would market the heck out of it.

But I do agree that stiff stuff feels nice. My new Venge feels WAY more stiffer than my old one and it’s very enjoyable.

For money saved you could invest that $300 into a wax chain setup and save more watts and still have money left over :smiley:.


#7

Yeah, in this instance I went from a Niner BSB to the new Tarmac so I was changing a lot of variables (including going to some Sworks shoes) at the same time. My old aluminum crank arms were also really banged up so I had to replace them anyways.

All I can really say is that I prefer carbon crank arms for feel and that is as far as I am willing to go in terms of performance benefits.


#8

It would be going on a Cervelo S3 2017 Ultegra Di2 6870 setup with Wickwerks chainrings. Everything else is what it came with and look keo 2 pedals (aluminum). I do like the look of the carbon, but just have zero experience with them. Does it feel stiffer?
In terms of weight, it’s only slightly less than a half of a pound (221 g) difference.


#9

Ooo, a half a pound weight difference is a pretty nice savings. And since you’ll probably have this crankset for like…ever…then maybe it’s not that bad of an upgrade!


#10

Not alu to carbon, but I went from a square taper cheap crankset to a 105 hollowtec (far from the stiffest) on a 64cm Trek aluminium frame (lots of flex!) and definitely notice the increase in stiffness. No idea if it transfers to speed but definitely feels an awful lot nicer to ride


#11

Nate, I can’t tell if you’re joking or not lol. I didn’t think a half of a pound was very significant. Are you still thinking the money is better spent elsewhere? I mainly like to do events of 50 miles and up for cycling, working toward triathlons if that helps at all.


#12

$300 for half a pound is pretty solid. Better cost/weight savings than a wheelset for sure.


#13

Aluminium cranks can’t be that bad as Shimano have stuck with them for years.


#14

For speed to $$$ spent half a pound for $300 isn’t very good. For weight for $$$ spend $300 for half a pound is pretty good.

If you’re doing 50 mile events and tris one day, aero upgrades are where it’s at. Better kit, aero helmet (or aero road helmet), nice waxed chain, low rolling resistance tires…all of those would make you faster compared to saving a half of a pound.


#15

Got it…thank you all for the help. I’m still undecided at this point, but you’ve given me a lot to think about. Last question, are there any known negatives to the carbon cranks? Longevity, stripping, seizing, or anything else I should think about? BTW Nate, love the podcast and the trainerroad program. The workouts are great and the podcast is the highlight of my week. Please keep it up!


#16

No real negatives, especially on the road.

One last thing to consider if you are getting the Quarq: the carbon crank arms are cheaper if you get them upfront with the spider, versus swapping them out later. It was $400 when I ordered them through Quarq to swap out.


#17

Thanks! Good to know since I had considered that as an option too!


#18

ehhhh rotating mass and gyroscope effect… not exactly the same…

My thinking exactly I have carbon Record on my old Pinarello, but every bike I ride daily is aluminum.


#19

BB386 FSA sexy carbon versus BB386 FSA ally Powerbox absolutely zero difference bar the weight.

BB386 FSA ally Powerbox to Cannondale Si BB30a absolutely zero differencebar the weight.

Includes out of the saddle sprinting, hard climbing, general riding including rough roads.


#20

Ohh lawdy!! Carbon vs Alum/Alloy Have you seen the Titanium EeWings Cranks from Cane Creek!!! I had a pair in my hand a few days ago and WOW, the cardboard box they were in weighed more than the cranks did… cool thing is you dont have to worry about peddle or crank arm strikes with them because your not going to hurt them… price is a whole different subject because they 800 ish and with power meter 1100 ish…