Cane Creek's new XX 44mm Traditional lower headset assemblies will let riders use tapered forks in frames equipped with a straight 44mm-bore 1-1/8in ZeroStack head tube.
When launched in June, this should help breathe new life into countless older frames out there and allow their owners to take advantage of the latest technology without having to upgrade their entire setup.
Since the 1.5in lower steerer will fit through the ZeroStack head tube – but the steerer and bearing together will not – the XX 44mm Traditional will move the cup and bearing to the outside of the frame.
This will add just under 10mm of stack height (hence the 'Traditional' nomenclature), but assuming the buyer sticks to the same travel as the old fork, and taking sag into account, the net geometry change should be less than one degree to the head and seat tube angles.
While this will open up the upgrade potential for current owners of ZeroStack-equipped frames, Cane Creek say the idea actually came from small-volume frame builders seeking a way to fit tapered forks into head tubes that weren't massively oversized and without requiring expensive and complex machining.
"After hearing from David Turner [of Turner Bicycles] and then speaking with Sean [Chaney of Vertigo Cycles], I was so excited by the problem-solving nature of his headset solution and its far reaching implications for both new and old bicycles using the ZeroStack standard that I produced a technical drawing the same day," said Cane Creek director of research and development Josh Coaplen. "The headset bottom is simply a 1.5in traditional with a 44mm diameter insertion sleeve that fits a frame using the ZeroStack standard."
"Custom builders, like Sean, may not have the tooling available to them to produce a tapered head tube. They also don’t want to make a 1.5in straight head tube for a cross-country or road bike," said Cane Creek marketing director Jason Grantz.
"ZeroStack is still used heavily on mountain bikes and is now making its way downmarket to hybrid/city bikes and more cost-sensitive mountain bikes that use a straight 1-1/8in steerer. So, this solution solves a problem and allows a builder to produce a ZS-standard head tube and still run a tapered fork through it. It also allows me to put a tapered RockShox on my 2007 BMC TrailFox, which I just might do."
Bear in mind that ZeroStack is not the same as a truly integrated headset – where the cups are part of the frame – and not all internal-cup head tubes will work. Compatible frames must have a straight 44mm internal bore but it's quite a popular fitment with models from Giant, Pivot and Scott all sporting appropriate dimensions along with heaps of others.
Cane Creek will ultimately offer two versions of the XX 44mm Traditional lower headset assembly: a high-end model similar to the company's 110 XX and made at the company headquarters in North Carolina plus a lower-cost option made overseas.