Kinesis Aithein Disc frameset

The Kinesis Aithein Disc maintains the performance and stiffness of the original rim-brake model, but thanks to differing geometry and the all-weather reliability and overall power of discs, it's easier to access and exploit for a broader range of riders.

I owned the original rim-brake version of the Aithein for around five years and I really rated it. I loved the speed, the fast handling and, thanks to how light you could build the frameset up with mid-range components, its agility.

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It was – and still is (the rim-braked version is still in Kinesis' line-up) – one of the best aluminium alloy race bikes out there. So when I saw that Kinesis had launched its latest disc model, which has a more relaxed geometry, I was worried it would lose some of its magic, especially in the bends. I needn't have…

The ride

The Aithein Disc is still a very fast and capable race machine that just loves to be hammered around. It's certainly helped by the top-end build that we have here, including Shimano Di2 and the deep-section Reynolds wheels, but the impressive levels of stiffness achieved by the aluminium alloy tubing mean the Kinesis is hugely responsive. It feels very efficient. Get out of the saddle to attack a hill or sprint and every ounce of power you put out goes straight to the tarmac.

While I don't mind a bit of climbing, I'd much rather be descending as hard and fast as possible. Something that the Aithein Disc let me enjoy, thanks to how composed it feels in the bends. With its slightly slacker head angle of 72.4 degrees (size 53cm) than my old version, it isn't quite as razor sharp on the handling front, but the differences are marginal.

With a 992mm wheelbase the bike feels flickable in the corners, and changes direction with ease should you need to alter your line at speed.

As a whole package, the Aithein Disc is confidence inspiring. The balanced front end, geometry-wise, means this is a bike you can ride very fast regardless of your skill level.

On some of my favourite downhills I loved the way I could just let the Kinesis go, thanks to the confidence it gives. There is just so much feedback coming through the frame and fork, the Kinesis feels like it can be controlled with just the lightest of touches.

On even the fastest, most technical descents the Aithein feels planted and surefooted, with tiny shifts of body position being all that is required to guide this thing through the tightest of bends.

Comfort levels are hugely impressive too – the Aithein Disc can easily put some carbon fibre machines to shame when it comes to maintaining feedback levels but reducing road vibration. Its tubing removes much of the harshness from the road without alienating you from what is going on beneath the tyres.

It all makes for a bike that you can ride for a long time, and quickly. I managed to get a few three-to-four-hour rides in on the Aithein during the test period and I didn't feel that I'd been riding a stiff, harsh race bike when I arrived at my destination. I felt relatively fresh and unbattered, while still achieving an impressive average speed overall. It's a high-speed mile muncher.

Frame and fork

While many brands use hydroforming to create different tube profiles on alloy frames, Kinesis uses a technique called Superplastic Forming. This involves heating the alloy until it exhibits superplasticity, which allows the creation of complex tube shapes using gas pressure.

It's probably most noticeable on the seat tube where it meets the bottom bracket shell. This helps create those high stiffness levels found when giving the Aithein some stick on the climbs.

As you'd expect from a performance frame, the front end starts off with a tapered head tube to increase stiffness for high steering and braking loads.

It also allows for larger cross-sectional areas where the tubes are mated and welded, like the oversized down tube.

The chainstays are also noticeably large where they exit the BB shell for power transfer, while the seatstays are a much more svelte profile to bring in some compliance for comfort.

To keep things looking neat and tidy, the cables (or wires) and hoses are sent internally through the front half of the frame, exiting just in front of the bottom bracket shell. It's not always the ideal solution, bringing the gear cables out straight into the road spray from the front wheel, but I'd be more concerned if the Aithein was some kind of winter trainer.

Speaking of road spray, many of you will be glad to see that the Aithein Disc uses a threaded bottom bracket shell rather than going down the press-fit route. So, you're getting easy maintenance and hopefully a lack of creaks that can be caused by grit and water getting between press-fit bearing cups and the frame.

Fork-wise, the Aithein Disc uses a Columbus Futura full carbon fibre offering. It has a claimed weight of 440g, which when paired to the 1,600g frame (53cm) makes for a good starting point for a performance machine.

Stiffness levels are very impressive, even when braking hard from speeds above 50mph, with the 12mm thru-axle keeping everything in line and taut.

Tyre clearance for both frame and fork is 28mm maximum.

The overall finish and the build quality of both frame and fork are high, and I'm a big fan of this Deep Purple paintjob, especially in the sunshine. There is also a Dazzling Silver option.

Geometry

Five sizes of frame are available, from XS through to XL – we have the M (53cm) on test. The geometry is, on the whole, performance-led, although the front end is a little slacker to slow the steering down a touch, making the bike less twitchy than a race bike without dropping the fun factor.

The numbers looks like this: a seat tube of 530mm, effective top tube of 551mm, and a head tube length of 162mm. This is paired to a 72.4-degree head angle, 74-degree seat angle, 410mm chainstays and that 992mm wheelbase.

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All of this gives stack and reach figures of 559mm and 391mm respectively, which is fairly typical of this size and style of bike.

Value

Rather than a full build, the Aithein Disc is available as a frameset only. That includes the frame, fork, headset, seat clamp, thru-axles, frame ports and cable guides, which allows you to run any gear system on the market. That little lot sets you back £800.

Aluminium alloy frames have seen a real surge over the years, especially as new materials and manufacturing techniques have delivered increased performance and comfort levels, so there is plenty of healthy competition.

> 29 of the best production frames to build into your dream bike

One competitor I'm keen to get my hands on for testing is the new Palace 3 Disc from Bowman Cycles, mostly because I consider the rim-braked Palace:R one of the best alloy bikes I've ridden.

The Palace 3 Disc is available as a frameset for £845. There looks to be a lot of similarities between it and the Aithein when it comes to the geometry and finishing details, although the Palace will take slightly wider tyres of 30mm.

> road.cc Frameset of the Year 2020/21

Cannondale's CAAD13 Disc was launched in 2020, and Mat was very impressed with it. He tested the Shimano 105 model which had an rrp of £1,899.99, but it is available as a frameset only for £999.99.

Weight-wise it looks pretty similar to the Kinesis, and not only does it deliver on performance, Mat also highlighted the comfort levels. It, too, can take 30mm tyres, with 6mm of clearance either side.

Conclusion

The Aithein Disc isn't just an excellent aluminium frameset, it's an excellent frameset full stop. If you want the stiffness and performance of a race bike without the associated twitchy handling, then the Kinesis is definitely one to consider. It's pretty good value too.

Verdict

Impressively stiff and efficient frameset, which showcases just how good aluminium can be