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Atomik building unique, single-wall foam-core carbon fat bike rims

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prototype Atomik Carbon fat bike rims with foam core

Atomik Carbon’s rim lineup continues to grow, this time with an interesting new process taking cues from things like hockey, skiing and even helicopter blades. What is that tech? Why foam, of course.

“We knew we wanted to produce a strong and light rim and decided it would have to be a single wall design,” said company co-founder Wayne Lee. “The problem with single wall rims is they tend to not be very rigid. We looked at different ways to accomplish this and decided that the foam ‘core’ would be the way to go. The foam core adds damping characteristics while also becoming a integral part of the structure, increasing rigidity and strength overall. This technology combined with the 12k weave outer layer works together to yield a light yet extremely strong rim. This process is much more difficult and time consuming to produce, but won out as the best method to produce a high quality, high performance product at a decent price point.”

Wanna see the inside? Join the foam party…

prototype Atomik Carbon fat bike rims with foam core
Cutaway is a prototype with 3K weave, production rims will use the 12K weave shown in other pics.

Typically, rims are made stiffer and stronger by using a double wall design. But Wayne told us that since the fat bike rims are already so wide, double wall construction was overkill. It also added weight, cost and manufacturing complexity. So, the foam-core single wall concept came about after exploring some of the tech their manufacturing partner was using in other areas.

The foam is hydrophobic, so it won’t absorb any moisture from snow, creek crossings or other muck you may ride through.

prototype Atomik Carbon fat bike rims with foam core

These rims will be tested in the Idatarod Invitational Race and Australian Outback this March. Assuming all goes to plan, they’ll enter full production and be available this August.

prototype Atomik Carbon fat bike rims with foam core
The 12K weave isn’t just cosmetic, it’s a structural component.

Tech specs are:

  • 85MM OD
  • 77MM ID
  • 500-540 grams target
  • 12K Weave
  • 14mm Offset
  • Hooked rim
  • 32 and 64 hole drilling options

prototype Atomik Carbon fat bike rims with foam core

Depending on how the light hits it, you may or may not see the weave from all angles. These have a matte clear coat on them, but Atomik’s working on a new exterior finish that will be unlike anything else out there…we just can’t tell you about it yet.

Following this rim will be a foam-core 27.5+ rim. That one will have a 36mm ID, 43MM OD and come in around 450g.

Not into fatties? Their XC and trail lineup was recently revamped to include both hookless and their “Mod-Hook” designs for anything else, and there’s a DH 27.5″ rim in development, too.

AtomikCarbon.com

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Bog
Bog
9 years ago

These look like pretty cool rims. It’ll be interesting to see how this single wall design translates to non-fat bike applications.

Tyler, the width of the rim should not be listed as an OD or ID.

Alex @ Hermes Sport
Alex @ Hermes Sport
9 years ago

US-made?

Steevo
Steevo
9 years ago

Not quite sure how this is single wall. There are two carbon walls sandwiching the foam core. True single wall would mean a solid piece of carbon, not one with a void or filler in the middle.

This is the same as almost all marine composite construction, foam or wood is commonly used to give a reinforced plastic supporting structure.

Cornelius
Cornelius
9 years ago

Foam-fiber composites have insane strength-to-weight ratios. I’ve always wondered why this construction technique wasn’t applied to wheels and frames.

codyish
codyish
9 years ago

@Bog – why not?

rodegeek
rodegeek
9 years ago

@codyish – The D in ID and OD typically stands for Diameter. Since width is not a dimension of a circle, there is no diameter in the measurement. But – one might argue that D stands for Dimension. Tyler, how about using IW and OW?

JBikes
JBikes
9 years ago

So if you fill a double wall with a material, it becomes single wall?

Whatever, it a good fit for this area of composite technology, and its good to see someone take advantage of it regardless of what they call it.

Drew Diller
9 years ago

JBikes yes it is sort of a single-double wall hybrid. I mean look at the cross section. It is two walls, very close together.

I think their reasoning is that if they claimed double wall, it’d be more of a stretch of the imagination and people would get pissed off. I think they made a wise choice.

Bobby Jack
Bobby Jack
9 years ago

I really like the idea and a step in the right direction.

TheBikeBondsman
TheBikeBondsman
9 years ago

Atomik Carbon Bravo. We are really looking forward to the direction this is going. The more options the better.

JBikes
JBikes
9 years ago

Drew, I think they should just call it what it is – a foam core composite rim.
And that actually has a more technical ring to it that cornering it into “single” or “double” wall status, while eliminating any negative connotation that either may have.

nsp234
nsp234
9 years ago

Cornelius, Foam was used in early Carbon frames. In most cases today it’s left away because with those rather large volumes of a Frame the foam would add too much weight. I guess the same applies to a rim with a more traditional shape/cross-section. In the case shown here the foam is really thin, so I guess the weight gain is minimal and well worth its price.

Veganpotter
Veganpotter
9 years ago

Yeah…definitely not single wall. That’s definitely a good thing because its a stronger wheel but they should say what it is. Even without the foam, this rim would benefit from the void and having the double wall

Bazz
Bazz
9 years ago

Too heavy, HED BD 85mm rims are 445 grams. For the same kind of money.

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