Hunt Takes Limitless to Next Level With SUB50 Limitless Aero Disc

Hunt‘s Limitless wheels set out to raise the bar in aerodynamic wheelsets. Starting with the 48 Limitless, and then the 60 Limitless and the 42 Limitless Gravel, the UK brand is now launching the next generation of Limitless technology, the SUB50 Limitless Aero Disc.

The new SUB50 builds off of the 48 Limitless. When first launched, the 48 Limitless started the trend of wider rim designs over 30mm, which is one of the benefits of disc brakes. These wider rims cheated the air like a deeper rim, but also provided more stability in cross winds, allowing riders to stay locked into aggressive, aerodynamic positions for longer, with less effort in fighting cross winds. They were able to keep weight down by using their patented Limitless Width Aero Technology which utilizes a strip of low-density structural polymer inserted in a molded channel within the rim sidewall with carbon molded over it, allowing for extra width while minimizing material mass. While other brands have caught up and even exceeded Hunt with wider rims, the white paper written on the development and aerodynamic testing of the new wheelset shows how the SUB50 sets a new standard for an all-around, 50mm wheelset.

If you want to dive deeper into the development, check out our article here.

During it’s development, Hunt only had a few design parameters: a rim depth of 50mm or below, a rim optimized for today’s 28 and 30mm tires, and decreased weight. Other than that, their engineers were open to try anything they wanted. So, they started with the 48 Limitless. From there, they began using Computational Fluid Design (CFD) to test various combinations of heights, external and internal widths, nose radius, and shoulder widths of rims. They also made the move to a hookless design that allows the tire to keep a straighter shape, following the shape of the rim better, improving aerodynamics and reducing weight at the same time. And even when they settled on a few designs to move forward with, they stepped back and looked at how they can optimize the rear wheel even further. Before we dig deeper, here are some things to consider.

• Aerodynamics – less drag means less effort to go faster or farther
• Weight – less weight means less effort to get up to speed
• Stability – more cross wind stability means less effort to at higher yaw angles

All of these contribute to make a great wheel, but also work against each other. Taller wheels tend to be more aerodynamic, but heavier and more susceptible to cross winds, making them less stable. Shallower wheels tend to be less aerodynamic, but lighter and less susceptible to cross winds. Keep in mind, those are some generalizations, but also generally true without diving into smaller details that we go into in the other article.

Also, while the front wheel is the leading edge on a bike, the rear wheel is shielded by the frame, and can be designed differently. The front wheel cuts through the air, with the front portion of the rim acting as the trailing edge, but also the leading edge as air begins to flow past the wheel again. The rear wheel is shielded by the seat tube, and only starts to see the air again as it is passing across the back portion of the wheel. This allows the rim to be designed specifically for this interaction, creating unique profiles front and back.

After all of the CFD testing, creating prototypes, trips to the wind tunnel with competitors’ wheels, and then another trip with production wheels and competitors’ wheels, we get the SUB50. The front measures in at 49.5mm deep, 34.2mm max internal width, and a 23mm internal width, while the back is only 30mm wide. Available with carbon or steel spokes and CeramicSpeed or steel bearings, they range from 1380g to 1420g a set.

In testing, the SUB50 was on par with the Roval Rapid CLX II and Enve 4.5 SES when it comes to aerodynamic drag and stability in cross winds, but is 130-140 grams lighter than the competition. While the DT Swiss ARC 1400 DICUT 50 DB tested faster with a 28mm tire due to it’s narrower internal width, it creates a narrower tire, and loses ground to the SUB50’s wider tire for less rolling resistance and improved comfort over rougher roads and cobbles. When you switch to a 30mm tire, the DT Swiss is almost 2 watts slower. Even the Zipp 454 NSW with a 5.5-8.5mm taller rim, was 1-3 watts slower, depending on the tire size used.

The SUB50 is more than just a new rim though. Available with Hunt’s TaperLock UD carbon fiber spoke technology, the upgraded spokes help to reduce the system weight by almost 50g while also improving lateral responsiveness by 6%. Unlike most other carbon spokes, TaperLock is fully true-able to keep your wheels straight. They also offer vibration dampening benefits, helping to smooth out rough roads and reduce rider fatigue. TaperLock equipped wheelsets use 18 spokes on the front wheel, 20 on the rear. Traditional spoked wheelsets use 20 Pillar elliptical spokes front and rear.

Hunt also used the H Ratchet DBL dual-sided ratchet system on the SUB50. The hub uses a double ratchet hub with a 40-tooth drive ring, offering 9-degree engagement and helps to keep weight down in the 6066 aluminum alloy hub. The new drive ring offers the same reliability and increased engagement surface area, while using less material than their pawl-based systems. The rings are also contained as a cassette, which means routine service. The axle uses a 7075-T6 alloy and the freehub body uses an H Ceramik reinforced coating to protect against gouging. Discs mount using the Centerlock standard, but 6-bolt adapters are available through Hunt.

The SUB50 will be available for pre-order starting today, with more stock arriving later this month. CeramicSpeed equipped wheelsets will be available late in April 2024. Pricing starts at $1799 for the steel spoked/steel EZO bearing wheelset. TaperLock spokes increases pricing to $2249, and the top level TaperLock/CeramicSpeed equipped versions top out at $2789. Wheelsets come pretaped for tubeless set ups, along with valve stems, axle adapters, and extra spokes. We’ll confirm freehub availability, but expect the standard Shimano/SRAM, XD/XDR, Campy, and Campy N3W.

We’ll have a set arriving later this Spring to put through their paces to see if they live up to the hype. We have already tested the 60 Limitless Aero Disc, and found them to be a solid performer. I like them so much, they continue to be my go to wheelset any time I’m not reviewing a wheelset. I’m looking forward to see how they perform, especially for a 135 mile event I have coming up in June on my new test rig, a Van Dessel Arch 65.

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