Just Riding Along Mahi Mahi 40 wheelset

The Just Riding Along Mahi Mahi 40 carbon disc wheels aim to be a do-it-all choice. They're very light and stiff, with a 40mm rim depth to help make them fast as well. You would expect this to come at a cost, and while the £850 rrp certainly doesn't make them cheap, they're more affordable than most of the competition, and offer extra customisation as well.

All Mahi Mahi wheels are handbuilt to order. The options include three different rim depths – 30mm, 40mm and 50mm – and hubs that can cater for all axle widths, cassette types and disc mounts imaginable. Sapim CX-Ray spokes are used as standard, but there is the option of brass or aluminium nipples, a choice of 11 colours and also many different decal options, with no extra lead time. The lead time is currently five days for all in-stock components, which is impressive for a full custom, handbuilt wheelset.

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Our test wheels have 40mm-deep rims with straight-pull Centerlock hubs, 12mm thru-axles, bright green nipples, and gloss black decals.

Just Riding Along is a British company based in Yorkshire that's been at the forefront of tubeless tyre use for almost two decades, initially as a website providing useful information about converting to tubeless, then moving on to create Wheel Milk, a tubeless sealant it still makes to this day. No surprise, then, that the Mahi Mahi and the majority of the JRA range are tubeless compatible.

Fitting tubeless tyres can be difficult depending on the tyre/rim combination, so it was very pleasing to find that several different tubeless road and gravel tyres fitted onto these rims with ease, without feeling like I was in a wrestling match. At the most, a single tyre lever was needed, which is encouraging – if you had to remove a tyre while out riding it should still be possible. I also tried the wheels with non-tubeless tyres and they fitted with ease, too.

The 22mm internal rim width is wider than the majority of wheels currently available that are aimed at road bikes, and the result is that most tyres will be wider. A pair of 25mm Vittoria Corsa (non-tubeless) tyres measured 29mm at their widest point. The increased width is said to offer better aerodynamics because of the cleaner transition from tyre to rim, and the wider profile means you can run lower pressures for extra comfort.

I tested the wheels with several different tyres, both tubeless and tubed, and at a range of pressures. JRA says they're suitable for running tyres up to 100psi, which should be enough to satisfy most riders, although JRA does recommend running lower pressures. I tested them with tubed tyres at 80psi and tubeless down to 70psi and had no issues with the tyre seating. The pressure used will ultimately be a personal choice, but with recommended pressures from 60-80psi it is encouraging for anyone looking to run lower pressures but fearing the risk of burping or unseating a tyre.

> How to choose your tyre pressure

The overwhelming initial impression is how responsive and laterally stiff the wheelset feels under acceleration, making starts at traffic lights and junctions all the more enjoyable. The stiffness on offer is particularly impressive given the low weight.

At 1,490g for the pair when weighed with rim tape fitted, it makes them a competitor for almost any other wheelset for weight regardless of price. They're 130g lighter and £250 cheaper than the Fulcrum Wind 40 disc brake wheels, for example. And though they're 19g heavier (but £20 less) than the Scribe Aero Wide+ 40-D (claimed 1,471g and £870), and Hunt's 4050 wheelset is cheaper and lighter at £789 and a claimed 1,458g, neither offers the customisation possibilities of the JRA.

The low overall weight of the Mahi Mahi wheelset is achieved without sacrificing performance: 24 Sapim CX-Ray bladed spokes are laced two-cross front and rear, and a Shimano freehub with 'Anti-Bite' steel splines prevents cassette wear from teeth digging in, which can be an issue on alloy cassette bodies. Multiple freehub options are available when building, including Shimano, SRAM XD, XD-R and Campagnolo.

The Just Riding Along-branded hubs are made by Bitex, a large and reputable company that makes many OE hubs. The bearings are extremely smooth front and rear and there is not a hint of play or drag, even after several thousand kilometres of testing. The 6-pawl, 48-point engagement freehub gives instant drive, and I had no issues with reliability of the freehub or bearing design.

The wheels also stayed perfectly true throughout testing, with no need to reach for a spoke key, and while the use of aluminium spoke nipples may not be everyone's preference, they help keep the weight low. You can, of course, have brass spoke nipples should you wish.

Aerodynamics is quite subjective without a wind tunnel, and JRA doesn't make any specific claims for the Mahi Mahi wheels, but they feel at least as fast as other wheels of similar depth used on the same bike. I rode them in all weathers, including on very windy days, and the performance in sidewinds is very good. In stronger winds you can feel the sideways pressure, but it is never sudden and they don't snatch as some older V-shaped rims have a tendency to at times. Even if JRA had offered aerodynamic data it would be impossible to verify in real world conditions, but the stiffness and low weight help make them feel fast.

The Mahi Mahi wheels are rated for both road and gravel riding and over several thousand kilometres I have used them on a wide range of surfaces, including extremely rough off-road tracks. They've had several big knocks but have remained true throughout.

As a gravel wheelset I tested them with tyres up to 43mm wide – this gives a good tyre profile, with the internal rim width supporting them on rougher terrain and at lower pressures.

Riding off-road, the lateral stiffness is evident and having taken them down a few tracks that are more mountain bike trail than gravel they have proven capable, holding a line at all times. Can a wheelset be too stiff? For some people a little lateral movement might at times be beneficial, but given the intended purpose of the Mahi Mahi wheelset, designed for faster riding, they achieve the goal.

> Buyer's Guide: 23 of the best tubeless wheelsets for under £1,000​

Some might see them as overkill for a gravel bike wheelset, but they could be ideal for the increasing number of gravel races and longer distance events emerging. You could also swap them between a road and gravel bike, if you have both types of bike.

Conclusion

Overall, these are impressively lightweight and extremely responsive carbon wheels with on and off-road capability. Installing tubeless tyres is easy, and they're a competitive price.

Verdict

Extremely impressive lightweight and responsive carbon wheels with on and off-road capability, at a competitive price