Review: Crankbrothers Iodine 3 Wheelset

The unique look of Iodine 3 wheels is unlike anything else on the market. At the center of the wild Twinpair spokes is a less exciting, but well-built set of hubs.


Construction

Crankbrothers Iodine 3 wheels are nothing if not unique. The aluminum Twinpair spokes and lacing configuration is claimed to create, "triangulated load bearing structures" which Crankbrothers believe offer "superior strength" despite the wheel's reduced spoke count compared to others in this class. The spokes are matched in pairs and join the rim at either side of a threaded aluminum dowel which protrudes through a central flange in the rim. The two-piece spokes thread together at their midpoints and to tension the spoke, you screw the segments together like a turnbuckle. Crankbrothers claim that one benefit of this design is that much of the strengthening material is away from the rim, where the additional rotational mass matters most.

Inside the rear hub is a three-pawl freehub with 21 teeth for engagement. Wheels are shipped with Shimano HG-type freehubs, but a SRAM XD conversion is available for $99 USD at the Crankbrothers web-store. Both front and rear hubs run on cartridge bearings. Front hubs can be spaced for 15mm or 20mm axles with interchangeable endcaps, while rears are 12mm x 142mm. At present the Iodine 3 wheels are not available for bikes running Boost front or rear configurations.


At the base of each spoke is a formed head, so there is little chance of the spoke pulling through the hub flanges. Inside the rim, you can see the undrilled internal profile that makes tubeless setups such a joy.

The spokes are connected to the rim via dowels that pierce through a flange in the rim. Between the spoke interfaces, excess material is machined away to reduce weight.


Installation

Maybe the biggest and most noticeable advantage for the wheel's construction is their tubeless compatibility. Because the interior of the rim has an undrilled surface, save for the valve hole, this means that they are tubeless ready out of the box, with no need for an additional rim strip. Not only does this save a little weight, it also makes setting them up for tubeless theoretically painless (although a couple of tires we tried did require the use of a compressor). We did, however, mount them on a range of tires with no issues whatsoever.


Riding

While the weight of Iodine 3 wheels on paper is on par with much of their competition, they did feel sluggish to get moving. Once up to speed they were fine though, rolling nicely. While they didn't flex noticeably, and it is always hard to talk about qualitative terms like stiffness in a review, there was a certain deadening quality to the ride from these wheels - they didn't pop and dance on the trail. Their biggest negative was the freehub, which was slow to engage and not something we'd expect to see at this price point.

With recent developments in wheel design it is easy to lose sight of the fact that things have improved incrementally, that equipment behind the curve of the latest trends is not obsolete. The 23mm internal width was fine for mounting anything short of full 2.5" DH tires, in other words: pretty much all of the available tires for all-mountain riding will pair well with these wheels without any problems. That said, today's all-mountain rims average around 26mm (30mm is not uncommon), which means that the Iodine's 23mm internal-width is as narrow as one would consider to be in this class.


Durability

This is where these wheels really shone. The rims were absolute tanks - we put them through six months and 2,000km of suffering on the rocks of Peille in Southern France, the same trails Nico Vouilloz cut his teeth on. For extra punishment they even spent some time on an electric-assist bike, which, regardless of your personal view on such bikes, is an excellent test bed because the bikes tend to weigh upwards of 20kg and out on the trail, that weight tends to make them blunt instruments when it comes to technical sections. Even with the additional abuse, the rims did not flinch once - they required a little spoke tension here there and the 20mm adapter on the front hub did get a little bit loose after six months use, but that is all. They stayed mostly true, with just some minor flat spots that, most importantly, did not affect the tubeless performance.

However, there is one thing to keep in mind with wheels like these: the design is completely proprietary. That means that if you have a good local bike shop who sell Crankbrothers you should be fine and you can, of course, order parts online. If you are the kind of rider who tends to break kit, we would recommend keeping spares to hand so you don't find yourself stuck waiting for them to arrive. We tried a few local bike shops to check availability of spares and the results were not reassuring, freehubs were easy to find, but we struggled to get hold of spokes which are likely to be the part that breaks most often.




Pinkbike's Take:

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