Hunt has released a disc version of its imaginatively named carbon-spoked 44 and 54 UD Carbon Spoke Disc wheels after the rim brake version of the wheel saw success being raced by Canyon DHB throughout 2019.
The wheels are claimed to be 6 per cent more laterally stiff than an identical steel-spoked wheel while presenting a significant – in the context of high-end carbon wheelsets anyway – reduction in weight.
The wheels are available in 44mm and 54mm depths and are priced at £1,069 / $1,299 and £1,089 / $1,319 respectively.
A carbon conundrum
Carbon spokes cannot be made in the same way as a regular steel one because it’s not possible to cut threads directly into carbon fibre.
Different methods for attaching spokes to both the hub and rim have been used throughout the industry, with most bonding the whole lot together as a single unit. Notable examples include Lightweight and Mavic's Cosmic Ultimate wheels.
(Mavic also offers the R-Sys wheelset, which uses replaceable carbon pillar spokes, but its construction is quite different to these wheels.)
Hunt’s wheels differ in that they largely resemble – and can be trued like – a conventionally spoked wheel.
Each carbon spoke is fitted with a flared aluminium cap (or mandrel, to use its proper name) at its base and a threaded steel cap at the top.
Rather than being bonded, these caps are placed on the spoke during the curing process. The spoke is flared and tapered at each end and the caps are mechanically wedged in place when they're slid to the ends of the spoke and tensioned.
While it may look like a nipple, the cap at the rim end of the spoke is actually permanently fixed.
An internal nipple can be accessed from the rim bed and threads onto the cap, allowing the spoke to be tensioned.
The cap features a standard square profile, so it can be held in place with a spoke key to prevent twisting.
At the hub end, a conventional straight-pull hub is used.
These spokes are claimed to be extraordinarily strong, with a maximum tensile strength of over 450kgf (kilograms-force). Conventional steel spokes will typically have a maximum tensile strength of around 300kgf.
It’s worth noting that most rims have a maximum allowed spoke tension below even the upper limit of a typical steel spoke, so while useful to illustrate the strength of the spokes, they should never reach these limits in normal use.
Hunt shares this technology – which it has dubbed as TaperLock – with Cadex, the in-house component and wheel brand of Giant Bicycles.
Stiffer, lighter and more comfortable
According to Hunt, in testing, the 20-spoke wheels pictured were shown to be 6 per cent more laterally stiff than an otherwise identical steel-spoked wheel with 24 spokes.
This, Hunt claims, “shows that we can achieve greater lateral responsiveness while also reducing spoke count and weight with carbon spokes”.
On the subject of weight, the 44mm deep wheels weigh a claimed 1,398g for the pair while the 55mm deep wheels weigh a claimed 1,456g. Hunt is usually spot on with its claimed weights, so we tend to believe these figures.
In terms of aero performance, the rims are based on existing designs from Hunt and, according to the brand's own testing, the wheels have aero performance that betters a Zipp 303 NSW or DT Swiss ARC 1100 Dicut 48.
As well as a reduction in weight and improvements in stiffness, Hunt also believes the wheels offer a smoother ride quality than a typical steel-spoked wheel.
This feels counterintuitive as a stiffer wheel should, in theory, feel harsher.
However, Hunt claims that the carbon spokes “exhibit a frequency-dependent loss coefficient that is well-tuned to absorbing high-frequency road buzz”. Or, in other words, the spokes are claimed to dampen vibrations more effectively than steel spokes.
This is one of the more intriguing claims made about the wheels and is something we're very keen to put to the test.
Lifetime crash replacement
To coincide with the launch, Hunt is also launching a free lifetime crash replacement for first owners of all UD carbon spoke wheels, alongside its Limitless and Aerodynamicist range of wheels.
This package covers any Hunt-branded/made part and will include any labour costs associated with repairing the wheels.
Riders will only be required to cover the cost of shipping wheels to Hunt’s base in either Colorado or the UK.
The wheels are available for pre-order now, with the first batch expected to arrive in July.
