Atomik Carbon has been very busy this year with some new tech & product we’ve seen, and some we (still) can’t talk about just yet.
What we can talk about are the new and finally released 27.5+ Chubby 43 and 26″ Fatty 85 wheels and rims. Atomik approached the Plus and Fat designs without considering traditional rim construction. Which is good, since these are by no means a “traditional rim”. With the goal of making them strong, light
cheap stiff, Atomic looked at the pros and cons of various rim constructions when going wide.
That said, I’m going to try and not explode with excitement as I’ve been
bashing riding a prototype set of Atomik’s carbon mid-fat wheels for the last few months and wasn’t allowed to talk about them. Now that they’re official, I’ve got the green light, so here it goes….
Atomik entered the “Plus” and “Fat” market with a “no limits, from scratch” approach as there were many things they wanted on the feature list. Like not skimping on performance while making sure the design was durable enough for real-world riding. They consulted with aeronautical engineers, F1 engineers and sporting goods designers that use carbon fiber in high-stress, high-impact environments. Those conversations led to a foam core and stronger single-wall design.
To reflect a little on the technology we’ve covered previously, the new Phatty 85 and Chubby 43 both use Atomik’s “Solowall” (single wall), and patented HDP (High Density Performance) Foamcore technology. The foam forms a lightweight structure and is hydrophobic so it won’t absorb water. It boosts the structural integrity and stiffness of the rim while allowing it to remain very, very thin. Just 15mm, to be exact. Why is this important?
Atomik considered how much more surface area would be exposed to carbon unfriendly rocks with a more traditional rim profile on 43mm and 85mm wide hoops and the flat design was the clear winner.
The first thing Atomik’s Wayne Lee told me to do was to keep track of the number of impacts. During their own testing, they discovered that approximately 75% of the rock impacts were happening above the 15mm line.
Coming up with a way to make a sturdy, yet light rim that is only 15mm deep was the reasoning behind this mad science. Even though the majority of impacts on carbon wheels result in merely cosmetic flesh wounds, the chances of structural damage are reduced significantly. And they will look pretty for longer too!
They use a custom “done in house” 12k carbon weave at their factory that is as strong as it is gorgeous. This method is to improve durability as well as structural integrity to increase strength, stiffness and impact resistance. All of that makes them strong in all directions to withstand forces from impacts as well as the additional lateral forces created by the increased traction by the larger tires when railing a turn (and oh do they).
Atomic chose to use a hookless bead design that has a virtual bead lock that is more of an angled “shelf” (center). This keeps the tire’s bead from slipping or loosing air if you’re running really low pressures. To better resist impacts, the rim’s bead is a whopping 3.5mm wide (left diagram), and is no doubt stout.
For bearing holders on the Premium Chubby 43’s, ($1,960), Atomik went across the bay (in Florida) to Profile Racing’s Tampa headquarters for their Elite “you’ll never have to say ‘on your left again‘” hubs. Having always set the bar high on the BMX circuit with their cranks, hubs and many other shiny goods, though not as well known as companies like Chris King or even Industry Nine. Profile has the fastest engaging, made in the USA hubs on the market and if you’ve never heard them…. you’ll know it when you do.
As a less expensive alternative, you can get them built with the also very nice DT Swiss DT350 hubs on the Standard Chubby 43s ($1,650). Both wheelsets use top shelf Sapim spokes.
Profile’s fit, finish, durability, and axle options are a good choice to compliment these premium wheels.
On the Fat side of things, the Fatty 85 Premium ($2,300), comes with Industry Nine’s Torch Fat Classic hubs and the Standard Fatty 85 ($1,825), comes laced on to DT Swiss’ DT350 Big Ride hubs.
Stay tuned for a more detailed piece in the near future featuring these portly hoops on a little Bikerumor project…