Enve's latest Twenty 9 carbon fiber 29er cross-country mountain bike has always been marketed as tubeless-compatible but now it's official, having earned genuine UST certification from the standard-keepers over at Mavic. Moreover, Enve says that information gleaned from the company's high-profile sponsorship of the Santa Cruz Syndicate team also makes these rims stronger and more rigid than earlier versions thanks to more impact-resistant laminates.
Claimed weight for a single 24mm-wide (external; 18mm internal), 31mm-deep hoop is just 385g, as compared to 330g for the equivalent 26" version.
"Our investment in new testing equipment has strengthened our ability to take real world results and feedback, validate it in the lab, and then reintroduce it to the athletes and testers to validate any of the changes we had made," said Enve engineer Kevin Nelson in a press release. "This process is very apparent with our new XC mountain rims. We took what we were learning from our test riders, and made changes accordingly. As a result, the new XC mountain rims are stiffer, stronger, and now tubeless."
As with all of the company's rims, one of the Twenty 9 XC rim's defining features are the molded-in spoke holes that are said to be stronger than ones that are drilled conventionally since no fibers have to be cut. The internal nipples still required pierced outer rim walls for access, though, so tubeless setups will require the use of airtight rim strips.
Unfortunately, Enve still hasn't gotten around the tubeless issue on its more versatile AM rims. According to Enve's Jason Schiers, the wider rim profile has proven harder to adapt to the UST in carbon and development has been pushed back far enough that there's currently no set timeline for release.
Schiers says that official UST approval for Enve's Twenty 6 XC rim is pending, however, with the delay being attributed solely to nuances in the approval process between the two different sizes.
However, one might wonder: Why the emphasis on UST certification while others - notably NoTubes and others like Sun-Ringlé that use the same licensed shape - have managed to successfully do the tubeless thing using rim profiles of their own design?
"We talked about doing our own and potentially working with Stan [Koziatek - founder and namesake of Stan's NoTubes]", Schiers told BikeRadar. "UST to us seemed the most user friendly and you have an enormous tire selection. It was an easy decision after all things were considered. The unique thing about UST is that they really push the concept that it can be inflated with a floor pump and not require a compressor. It was more challenging than we expected to get approval especially with the holes in the rim but the bead lock concept is an additional security feature that we thought was attractive both as a manufacturer and for consumers."
Enve will offer the new Twenty 9 XC as part of a complete wheelset with DT Swiss or Chris King hubs, or as standalone rims in 28 or 32-hole.
Retail pricing is expectedly on the premium side of things. A set of Twenty 9 XC tubeless clincher rims laced to Chris King quick-release hubs will run you US$2,550; subbing in a pair of DT Swiss 240s hubs will change that to US$2,500; and using thru-axle DT Swiss hubs will cost US$2,520. The bare rims will cost US$899 each.
This article originally appeared on BikeRadar.