Wheels and Tyres

CrankBrothers Iodine 2 wheels

Wider rims and tougher hubs from Carl and Frank

CrankBrothers have a distinctive design that is carried throughout their wheel range making them immediately recognisable. We have the new generation Iodine 29″ wheels in for long term test – these are our thoughts so far.

Words: Sean White Images: Ieuan Williams

There are plenty of head turning concepts in the mountain bike world. Products that take a different approach to the usual ways. Often, they are striking and controversial in their visual appeal and stir up questions regarding the engineering that is said to back up these designs. We’ve seen plenty over the years. Manitou’s Reverse Arch forks (and Pace too…), the single sided seat tube of the Specialized Demo 8, Cannondale’s Lefty fork and 29″ wheels all looked wrong at first sight and took time to visually adjust to. It was the same with the wheels from Crankbrothers. As with their pedal range they do things differently but over time have brought to market some winning designs – the Crankbrothers Mallet DH pedals have been a pick in the 2017 Dirt 100 and for many years before. Their wheels however, impressed us in certain areas but haven’t always gone the distance and held up to testing UK conditions. This latest range, the third generation, promises to deliver.


Mavic were the first with pre-built wheel systems (as far as we can remember…) and in 2017 a tubeless compatible rim and cartridge bearing hub on an ‘off the peg’ pair is now almost the norm. Spoke counts can vary from very low (24 on the front of Roval wheels from Specialized) to the ‘old standard’ of 32 (on Hope Hoops). Crankbrothers developed their Twinpair spokes and have stuck with this concept – it’s a system they believe in. These chunky black stainless steel spokes thread together from two shorter sections and are adjusted in the centre rather than at a nipple that sits into the rim. This design allows spokes to be replaced without removing the tyre and uses a rim with no spoke holes, resulting in a reliable tubeless seal. Here’s what Crankbrothers feel are the features and benefits of this system:

Massively different
Simple and beautiful – this unique wheel design is based around principles of strength, stiffness and acceleration.

Faster to accelerate
Low rotational inertia – a wheel design that distributes mass closer to the hub for faster acceleration and deceleration.
Tubeless ready – hole-less rims: stronger and no rim tape required for tubeless setup.

Stronger and stiffer
Twinpair spoke technology – designed using the strongest shape in construction, the triangle, to maximize strength and stiffness.
Beautifully simple – single spoke length: easy to true and replaceable without removing tire.


After my initial questioning of the looks, I fitted them to a long-term test Specialized Stumpjumper. Shod with some quality rubber (Maxxis High Roller II and Minion DHF) these looked very much up to the job. With the 29″ size weighing in at 1900g for the cheaper Iodine 2 model (the marginally lighter Iodine 1 wheels are 1830g) and with an internal rim width of 28mm these wheels are both up to date in dimensions and not worryingly dainty. The aluminium rims are also anodised black for a durable finish. Pricing (and weight) compares well to the Stan’s NoTubes Flow MKIII wheels which were another pick in the 2017 Dirt 100.

‘Enthusiast-level aluminium wheels for enduro’ is the tag line Crankbrothers hang on this hardware.

First impression were very good. These Iodine 2s were a touch heavier than the wheels we removed from the bike but they felt different. Different in a good way. They had a very pleasing ride quality, feeling stiff under power but not harsh in any way. Test conditions were dry with repetitive roots, rock gardens and braking bumps. There seems to be a compliance to the way these Crankbrothers wheels ride yet they remain stiff enough and light enough under power with good acceleration. Sure you know they are approaching 1900g a pair in weight but with a 90kg rider on board they felt suitably robust and hold their line well, giving some accuracy and precision to the steering.

So what about the hubs? Well, with nearly six months of use these wheels they haven’t missed a beat. The steel freehub body (a nice touch) and bearings are spot on. The wide rims have held the tubeless tyres tight, with no burping or leaking and the spoke tension has not needed adjustment.

A faultless performance so far, these wheels have won me over – they are staying on the bike…

PRICE: £499.99

SPEC OPTIONS: 29″ Boost, 27.5″ Boost, 27.5″ Standard (100mm/142mm)

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