Cadex 50 Ultra Disc Tubeless

The Cadex 50 Ultra Disc Tubeless wheels deliver impressive stiffness and a tangible sense of speed, which partly justifies their premium price. However, when paired with certain tyres their stability in the wind can make for a challenging ride. One thing's for sure – the freehub is loud enough to make sure everyone knows you're freewheeling.

For more options at a variety of prices, check out our guide to the best road bike wheels.

Every component of the Cadex 50 Ultras is designed with aerodynamics in mind, from the rims to the spokes and even the hubs. Cadex claims that these wheels deliver best-in-class performance in aerodynamics, efficiency, stiffness and weight.

As the premium sub-brand of Giant, Cadex offers a range of high-end wheels, tyres and components aimed at gravel, road riding and racing. The 50 Ultra Disc Tubeless wheelset is designed for versatile road use, whether on flat terrain or hilly routes, blending low weight and aerodynamics to perform in all conditions.

With a claimed weight of 1,349g (595g front, 754g rear), it compares impressively to its competitors. However, our set weighed in slightly heavier at 1,415g (635g front, 780g rear); this includes tubeless rim tape and valves, which may explain part of the 66g difference, though not the entire discrepancy. Nonetheless, even at 1,415g, the wheels remain competitive among premium options.

At the core of the wheels are Cadex R3 C-40 aero hubs, equipped with ceramic bearings and freehub options for SRAM XDR, Shimano and Campagnolo, with a 40-tooth engagement.

You might wonder what makes the hub aerodynamic – likely the low-profile central design paired with tall, narrow spoke flanges.

The wheels feature deep carbon fibre spokes with an aerodynamic profile that aims to reduce lateral flex. Notably, the spokes use external aluminium nipples, making maintenance much easier if necessary.

As suggested by the name, the rims are 50mm deep, with a tubeless-ready design. The rims are hookless, which may not appeal to all, but Cadex claims this design offers the best flow transition from tyre to rim, reducing aerodynamic drag compared with traditional hook bead rims. The continuous carbon fibre structure is also said to improve overall durability.

The rims measure 22.4mm internally and 30mm externally, with 24 spokes at the rear and 21 at the front. The maximum rider weight (rider, bike, and kit combined) is 129kg.

Tyre compatibility and maximum air pressure recommendations are often areas of concern for those hesitant about hookless rims. Cadex recommends running the wheelset as a 'WheelSystem' with its own tyres. While most hookless rims are limited to 72.5psi (5 bar), Cadex has tested a range of tyres – including some non-Cadex models – that can be run at higher pressures. It also provides a list of tyres that have failed its tests and are not recommended, including popular models from Vittoria, Pirelli and Continental.

Although it might seem confusing, the key takeaway is that you can run any tubeless-compatible tyre at up to 72.5psi (5 bar), except for those that didn't pass Cadex's testing.

Setup & performance

I initially tested the wheels with Cadex Aero Tubeless tyres in a 25mm size. Removing and refitting the tyres was reasonably easy, though I did need to use a tyre lever. When we reviewed the Cadex 65 wheels,  Cadex advised against using tyre levers, likely because of the thin 3.6mm rims, but fortunately this recommendation doesn't apply to the 50 Ultras, and Cadex even includes two tyre levers with the wheelset. Inflating the tyres was simple using a track pump, with no air leakage.

I also tested the wheels with 28mm Schwalbe Pro One tyres, which are listed as "passed" on Cadex's compatibility list. Installation was similarly straightforward, again requiring just one tyre lever, and throughout months of testing the tyres have remained airtight.

The wheels spin smoothly with minimal friction in both the bearings and the freehub. However, the freehub is extremely loud; that's not necessarily a downside, but it won't suit everyone's preference. Personally, I've always liked louder freehubs, but these are on another level, possibly the loudest I've ever encountered.

Initial impressions were very positive. The lateral stiffness is noticeable, making it feel like every watt of power is being directly transferred into forward motion with no energy wasted in lateral flex. Compared with the wheels previously fitted to the bike, which were also quick and responsive, the Cadex 50 Ultra Discs feel far more direct, and almost addictive, enjoying the accelerations from junctions or slow speeds.

Comfort is another highlight, with the carbon spokes likely contributing to this. The wheels do a good job of absorbing high-frequency road vibrations, slightly improving the ride quality. However, even with a tubeless setup, the narrow 25mm tyres soon get overwhelmed on anything less than a perfectly smooth road, tyre volume making a bigger difference than the wheel and spoke material.

Given the low weight, I expected the wheels to excel on climbs, but the difference with the previous set wasn't as noticeable as I'd anticipated. Despite a 400g reduction compared to the previous wheels I used, they didn't provide the immediate climbing boost I'd hoped for. This may be down to weight distribution or perhaps the reality that, in practice, weight reduction doesn't always make as big a difference as one might expect.

Cadex claims these wheels offer stability in all conditions. However, during the first few rides I was reminded of my experience with the Cadex 65s, which were challenging even on moderately windy days. With the 25mm Cadex Aero Tubeless tyres fitted, I felt I was being buffeted by the wind, losing some confidence in certain areas.

Surprisingly, after switching to the larger-diameter 28mm Schwalbe Pro Ones, stability in windy conditions noticeably improved. I'd never experienced such a marked difference from a simple tyre swap, and with no data to explain this, I can only speculate that the improved stability comes from better airflow transition between the tyre and rim. You can still feel some effect in the wind, but they feel more constant, with no snatchy movements, and I find this has the biggest difference in confidence.

I did most of my riding with the Schwalbe Pro Ones, and with the added stability I began to enjoy the wheels even more. Cadex provides a basic tyre pressure guide which aligned closely with my usual settings. Lowering the pressure by 15psi (1 bar) when using the wider 28mm tyres greatly improved the ride, especially on rougher roads and lanes.

> How to choose the best bike tyre pressure – balancing speed, comfort and grip

The wheels' lateral stiffness also positively impacted handling, making sharp direction changes feel precise. That, combined with a tyre that provided excellent grip and control, meant I found myself seeking out twisty routes and fun descents in my local area. The wheels handled high-speed descents with ease, and although speed wobbles depend on multiple factors, I felt confident pushing the limits, descending the steepest and fastest slopes.

Value

At £2,649.98, the Cadex 50 Ultra Disc Tubeless is undeniably a premium wheelset, but it's not the most expensive option on the market – take the Enve SES 4.5, for example, which Jamie recently hailed as the best hookless wheelset available. Testing them side by side would be an interesting experience, but even if the Enve wheels prove superior, they come at a significantly higher cost of £3,350.

A similarly specced wheelset on paper is the Hunt SUB50 Limitless Aero Disc, which features a 40-tooth ratchet system, carbon spokes, hookless rims, and comparable claimed weight. The Hunt wheelset has a notably wider 34mm external front wheel, which Hunt claims improves aerodynamic performance, and is priced more affordably, starting at £1,849 with stainless steel bearings, or £2,289 for the CeramicSpeed option.

Conclusion

My initial experience riding the Cadex 50 Ultras was mixed. They impressed with their acceleration and cornering agility but felt unstable with the Cadex Aero 25mm tyres. Despite Cadex's claims of top performance as part of a wheel system, switching to a different tyre brand made a substantial difference. The larger volume tyres improved comfort and added stability, giving me the confidence to push the wheels even on windy days. Ultimately, this transformed them into a wheelset I thoroughly enjoyed riding.

Verdict

Impressive stiffness and overall performance with the right tyres fitted