Earlier this year while Minnesota was trapped in Nature’s icy grip, we met with Mauro Bertolotto of Raceware Srl. Mauro was very excited to show us a special project he had been working on – the first Kuroshiro carbon rim. Unlike most companies that specialize in high end carbon goods, Kuroshiro was starting with products specifically designed for fat bikes. Using a number of intriguing technologies, the Enso 685 was designed to be one of the lightest fat bike rims on the market.
Now, Kuroshiro is introducing their second product, the all new Enso 950. After deciphering the naming structure, we’re left with a 29” rim that is 50mm wide. Perfect for the growing 29+ market. Created to be just as impressive as the 685, the 950 continues with a bit of new carbon technology to offer even higher performance.
Just like the 685, the feature packed 950 won’t come cheap, but it’s not every day you can drop 5 pounds from your bike with a single swap…
Just like the Enso 685, the 29+ version of the rim uses Kuroshiro’s patent pending SP-line rim reinforcement. By using a continuous ridge of carbon that connects the anchors of each nipple, the SP-line design claims to boost stiffness by 22%. Since the spoke holes themselves are reinforced with the extra cabon, nipples can be run without washers. As with the 685 this allows the Sapim Super Spokes to be run at higher tensions which eliminates the need for tubeless tape.
Enso rims simply seal up tubeless with sealant and the pressure between the nipple and the specially drilled holes in the rim alone. Mauro points out that the amount of tape typically needed to seal 29+ wheels comes in about 40g per set.
While the SP-line is similar to the 685, the 950s have a big changed to the actual structure of the rim to increase stiffness. Since 29” rims are inherently larger than 26”, it takes more engineering to make them as still so Kuroshiro introduced a special box section to the rim. More than just a double wall section though, as you’ll find a special closed cell cross linked polymer inside.
Using a proprietary process, the polymer is added to the box section before the final layer of carbon is added to the top. Used in airplane wings, rotor blades in turbines, and racing boat hulls, the polymer ends up boosting the stiffness of the rim without adding much to the weight and decreasing vibration as well.
While hookless rims might be catching on in other areas of mountain biking, fat bikes seem to be holding onto the hooks for now. Kuroshiro says this is due to the fact that they can build a strong and precise bead lock thanks to Alchemist’s proprietary carbon skills that will resist rock impacts and damage from riding with low pressure.
One of the growth factors in the rise of 29+ wheels and tires, is that they make an excellent “summer” set up for fat bikes as well as dedicated 29+ rigs. There are many fat bikers who will choose to keep their fat treads year round, but just about any fat bike is able to run a set of 29+ wheels and tires. This still provides gobs of additional traction and flotation compared to standard 29ers, but increases the speed and agility of the bike compared to full on fat. Mauro points out that the 29+ Enso 950s are also capable of being run on most 29ers with 2.2-2.4″ tires. Mauro set up a Salsa Fargo with the Enso 950 wheels and standard 29″ tires and noted an increase in traction over the standard wheels.
Already in one of the last stages of preproduction, Kuroshiro hopes to begin full scale production next month after less than 18 months of development. Enso 950s will be offered in rim only or in complete wheels with Sapim Superspokes and American Classic 130/225 hubs. On Mauro’s scale the rims come in at 398g a piece with complete wheelsets as low as 1,560g. That means that when compared to a set of standard Surly Krampus wheels the Enso 950s are an incredible 2,560g lighter. That’s over 5 pounds!
Kuroshiro rims are 100% designed and made in Italy, with the Enso 950s retailing for 849 Euros. The US price is to be determined with the same going for the price of the complete wheelset. All wheels include a two year warranty and are eligible for a crash replacement policy. Enso 950s can be ordered now with the first rims expected to ship to Italy, Switzerland, Germany, and the UK by the end of the month.