When the topic of carbon rims comes up, often the question to follow is how harsh are they? Or, to use fancy words: what is the radial compliance? There has been some debate on whether radial compliance is actually noticeable in a carbon wheel versus an aluminum wheel. NOX Composites wrote about it, essentially saying it is a myth. And they have a few equations to backup the claim. Stan’s thinks differently. With its new CB7 carbon rims, the company claims a measurable 10 millimeters of radial compliance. That is no small number. Stan’s claims the new rims absorb impacts, damp vibrations and roll faster.

Stan’s has released two new CB7 rims and wheelsets -- the cross-country-specific Crest and the trail-specific Arch. Both are available as rims only or in complete wheelsets. The Crest CB7 rim weighs 325 grams, firmly placing it among the lightest cross-country rims, with a 23 millimeter internal width. The Arch, on the other hand has an internal width of 26 millimeters and the rim weighs 450 grams for a 27.5-inch wheel, or 475 grams for a 29er.

Let’s dig into this claim of radial compliance though. Stan’s NoTubes is calling it RiACT, and the company is claiming it is the first to design a laterally stiff but radially compliant carbon rim. The rims are created with a high-impact-resistant nano-elastomer resin. Stan’s says that means greater overall strength while being able to deflect 10 millimeters radially, or inward. Yes, we already said that. Yes, it deserves to be said again. Stan’s claims that even with the radial compliance, the wheels are laterally stiffer than aluminum rims. Oh, and they claim the design virtually eliminates pinch flats.

Like other Stan’s wheels, the new CB7s received Bead Socket Technology (BTS). The technology is supposed to make for easier tubeless setup and reliability. It is also a lower profile design, which the company says means less weight, stronger sidewalls and a more effective tire shape.

Both rims will be available in 28-hole and 32-hole configurations. If you want an entire wheelset, as opposed to just the rims, there will be several stock 28-hole options, or you can design your own configuration with seven different colors and hubs for almost any axel spacing. The wheelsets are laced with Sapim Force j-bend spokes that are easily found at most bike shops.

Both rims and wheelsets come with Stan’s two-year carbon warranty program. If you register your wheelset, that warranty gets extended for a total of five years of coverage.

There are a lot of claims with these new wheels. We are going to hold off judgement until we get a pair to test. Keep an eye out for that.

Here are all the specs on both wheels:

Crest CB7

Use: Cross Country Racing
Internal Rim Width: 23 millimeters
Optimal Tire Sizes: 2.00 inches to 2.25 inches
Hubs: Stan's Neo with Durasync 28-hole Front, 28-hole Rear
Spokes/Nipples: Sapim Force Black 2.0/1.7/1.8 millimeters, Sapim Secure Lock Alloy Black
Wheel Weights and Sizes: 1,452 grams (29 inch)
MSRP: Wheelsets – $1,400, Rim – $600

Arch CB7

Use: Trail, All-Mountain and Enduro Racing
Internal Rim Width: 26 millimeters
Optimal Tire Sizes: 2.25 inches to 2.50 inches
Hubs: Stan's Neo with Durasync 28-hole Front, 28-hole Rear
Spokes/Nipples: Sapim Race Black 2.0/1.8/2.0 millimeters, Sapim Secure Lock Alloy Black
Wheel Weights and Sizes: 1720 grams (27.5") / 1794 grams (29")
MSRP: Wheelsets – $1,400, Rim – $600

Stan’s NoTubes

Related:

Stan’s Bravo Pro vs. Mavic XA Pro Carbon