Stan’s NoTubes has introduced the new Flow CB7 and Baron CB7 carbon rims and wheelsets, featuring an entirely new asymmetric version of Stan’s patented Bead Socket Technology (BST) tubeless rim design developed in partnership with Ibis Cycles.
Stan’s notes that asymmetric rims with offset drilling allow for more balanced spoke tension and a stronger overall wheel, but until now, no asymmetric rim has been able to match the light weight, easy tubeless tyre installation and inflation and reliable airtight seal of a genuine Stan’s BST tubeless rim.
‘The new Flow CB7 and Baron CB7 combine the benefits of an asymmetric rim with the low weight, reliability and ride.’
The company adds that the shape of a well engineered tubeless rim is designed to guide a tyre’s beads up and out of the centre of the rim to the sides as smoothly and efficiently as possible for easy inflation. Drilling off-centre spoke holes into one of the slopes that the tyre bead slides up during inflation interferes with a tyre bead’s transition, making rim tape placement and proper sealing more difficult.
By taking advantage of the added width of rims like the Flow CB7 (29mm internal width) and Baron CB7 (35mm internal width) and carefully studying tyre behaviour during inflation – rim shape and spoke hole location were optimized to work together, making inflation easier.
Another practical challenge to designing an asymmetric tubeless rim is the need to synchronize the motion of the tyre beads during inflation, so that both snap into place at the same time to create a reliable tubeless seal, even if one side of the tyre has to travel further than the other.
Working together, Stan’s and Ibis did extensive testing and refining until the final rim shape was perfected. Tyre installation, inflation and removal are ‘now as quick and easy on asymmetric BST rims as they are on Stan’s conventional symmetric rims.’
Once a tire is inflated, a tubeless asymmetric rim has to be completely reliable and provide control, especially in corners. The difference in the shape of the two sides of an asymmetric rim makes achieving consistent bead retention and impact strength on both sides more challenging, but after several design iterations… ‘Stan’s was able to develop an asymmetric rim shape that not only maintains equally reliable seals when subject to off camber situations and the most aggressive cornering, but also withstands impacts equally on both sides.’
Having consistently reliable seals and impact strength on both sides of the rim mean that there is no ‘weak side’ of the asymmetric design, drastically improving overall wheel performance and rider confidence.
The Flow CB7 is a lightweight carbon trail rim featuring a new asymmetric version of Stan’s Bead Socket Technology rim shape. The new carbon Flow CB7 relies on an added lay-up process to increase strength while keeping weight to only 420g for the 27.5” rim and 455g for the 29” model. The 29mm inner width of the Flow CB7 is optimized for 2.35” to 2.6” tyres.
The Baron CB7 incorporates the same new asymmetric Bead Socket Technology as the Flow CB7 for added strength and lower weight, but its 35mm internal width makes it a choice for even wider tyres.
Stan’s NoTubes, founded and owned by Stan and Cindy Koziatek, forged a path for making mountain bikes tyres tubeless. Stan Koziatek devised the original NoTubes sealing system in 2001, the same system that today has become a preferred tubeless conversion system around the world. Stan’s NoTubes currently designs, produces and sells innovative mountain bike, road and cyclocross wheels, rims and hubs as well as a range of products for tubeless conversion.