Wednesday, September 23, 2009

Testing: Crank Brothers Cobalt XC Wheelset

I decided late last season that in 2009 I wanted to try Crank Brothers new Cobalt XC wheelset. Main reasons being both that I like to try new stuff and also because I thought they would match my new Anthem X0 perfectly.
Aesthetically the wheels are amazing. They have an overbuilt but minimalist look to them. I get tons of comments and compliments about them. If you own them you better learn if you like them and why. You are going to get asked that a lot.

The ride
What can I say....they roll along quite unspectacularly, which should be thought of as a good thing. They made it through my season drama free with just one loose spoke. They are fairly light which helps with steering and suspension responsiveness. They sealed up tubeless really easily and I only burped air once at Tremblant which was entirely my fault.

Specs and tech notes
Like I mentioned besides the loose spoke the wheels stayed very true. Bearings all remained intact and smooth rolling. The hubs utilize multiple cartridge bearings like many wheels and are super easy to take apart, mostly tool free. This includes disassembly for servicing including freewheel maintenance. Weight is a safe 1500grams, which is fairly common for this price range and is equal to their Shimano XTR and Mavic Crossmax SL rivals. Spoke tension is adjusted via the long blue spoke nipples where the stainless spokes thread in about 1/2 way through the diameter of the wheel. They are no more difficult to true than conventional wheel designs.
I did have some issues with the freewheel sporadically making a loud metallic pop. I also experienced this with my XTR 970 wheels last year. It's like the pawls don't fully engage and eventually pop into place under load. I experimented with different grease viscosity's and eventually found success with a fairly light coating of Rockshox Redrum which all but eliminated the ping.
On another note I also had a strange occurrence with the Cobalt's. I mounted up some Tubeless Ready Hutchinson Piranha's and have been running those for the past couple months. I kept having the tires slide on the rims under braking. Not hugely noticeable while riding but you could see it adding up over time since I always line the label up with the valve stem. Now I'm not sure if this was the tires or rims or both since I didn't run any different tires for any length of time. So just something to look out for. Could have just been a fluke so I'll have to investigate further.

My Impressions
So what do I think of the Cobalt's? They served their purpose very well. They made my bike look great, kept rolling along problem free, and even stayed perfectly true. I must say from a functional perspective these wheels really offer nothing special. Any design differences compared to Mavic or Shimano can really only be considered gimmicks. Despite this I was still very happy with them and would recommend them just as I would the XTR's and Crossmax's. Pretty much go for the ones that match your bike.

-easy tire sealing

Needs Work

-freewheel engagement

Value - 3 Power Rangers out of 5
Performance - One dozen delicious doughnuts out of a bakers dozen.

Actual weight
Front wheel - 703grams
Rear wheel - 860grams
Front skewer - 60grams
Rear skewer - 64grams
Valve stems - 6grams each

The Cobalts look pretty.

Tire sliding on rim. Note the valve stem used to be lined up in the middle of the printing on the tire.


  1. Hey Benno - what do you have to do to the Cobalts to make them ready for tubeless (UST) tires? Do you add a kit? If so, how much extra weight?

    I'm looking at getting a pair for this year, and want some practical info on the tubeless thing. I'm problem for weight?

  2. Like all true tubeless wheelsets the rim is completely sealed so all you need is the valve stems which are provided with the wheels. If you get a flat you can just pop out the valve stem and install a tube as usual.
    The Cobalts are some of the sturdiest wheels I've ever ridden and they will handle you weight no problem.
    Looks like the Cobalt XC's will now be offered in black, blue,and champion (silver??).

  3. Can I ask you , how you true this wheel, its clasical like other one piece spoke? or its more different

    1. The wheels are simple to true. The blue alloy part is like a long spoke nipple, you just turn that to make your adjustments. I think it just takes a normal spoke wrench.

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