Kinesis Aithein Disc review

In a world of truncated aerofoils, proprietary headsets and dropped seatstays, the Aithein is a refreshingly uncomplicated aluminium road bike that uses no non-standard parts.

The bike's frame tubes are said to be shaped via ‘superplastic forming’, a process that involves heating aluminium to high temperatures before using gas pressure to form the tubes. This is said to have advantages over more common hydroforming techniques.

Normally the preserve of steel road bike frames, the Aithein Disc’s top tube is straight and perfectly round, while the seat tube and down tube have relatively simple profiles too, although the former flares above the bottom bracket shell for added stiffness.

The seatstays are straight and exceptionally stout and, despite this being a disc-only frameset, they’re joined by a substantial bridge above the rear tyre.

The Aithein is a bike with racy intentions and few concessions, so clearances are modest, with a quoted 28mm maximum tyre size. There are also no mounts for mudguards or other accessories.

While the geometry is fairly standard race-bike fare, sizing runs on the larger side, with 559mm stack and 391mm reach on a medium.

As the build is up to you, however, sizing up or down and choosing appropriate finishing kit to get your desired fit presents no obstacles.

At 174cm tall, I rode a 53cm bike with a 100mm stem for a semi-aggressive position, but could have dropped to a 50cm with a longer stem to get properly low.

While the Aithein is sold as a frameset, Kinesis owner Upgrade Bikes supplied us with a fully built test bike sporting a Shimano Ultegra R8000 groupset – 105 front derailleur excepted – and Upgrade’s own alloy clinchers. A build like this would set you back about £2,680. Dropping down to Shimano 105 would save around £270.

The wheels are tubeless-ready and built on neat-looking straight-pull hubs.

Upgrade now imports US brand Thomson’s iconic finishing kit, so it provides the bar, stem and seatpost.

The saddle is a very svelte perch from Italian brand Repente.

It’s an interesting shape that combines a fashionably short nose – albeit not as short as Specialized’s Power – with a cut-out and wings that taper down noticeably at the front.

Kinesis makes no bones about the Aithein Disc’s racy demeanour. It’s designed for fast, aggressive riding and will appeal to road and criterium racers. Its stiff frame makes it an excellent climber and a precise high-speed descender, too.

The overall ride quality is reasonably smooth, made more so by the posh handmade Challenge tyres, but on surface-dressed (ie chip seal) rural B roads, it’s not as relaxing as some of the competition.

While it’s not harsh, it’s certainly firm and direct, and shines brightest on good tarmac where you can exploit its supremely stiff back end and really put some power down without sub-par road surfaces ruining your fun.

Given the fat 31.6mm seatpost and chunky old-school seatstays, the uncompromising nature of the Aithein’s ride quality is no surprise.

The full carbon fork does a pretty good job of absorbing bumps, but square-edge pothole impacts are communicated directly from the rear tyre to your backside.

As such, the Aithein is an engaging ride on days when you’re on the rivet and feeling strong, but it’s perhaps less suited to chilled-out longer rides, particularly if they include a lot of dodgy road surfaces.

When you’re in the mood, however, there’s a pleasing analogue simplicity to the ride experience. Put simply, it’s fun.

The Aithein Disc is a single-minded bike, but it looks great and is hugely enjoyable for the right kind of riding. Rivals such as Cannondale’s CAAD13 are certainly more refined, but the Aithein has charm of its own, and it’s good value too.

If versatility and long-distance comfort are priorities, you’ll be better served elsewhere, perhaps by other models in Kinesis’ own range.

For fast club riding or racing, however, it’s an appealing option that you can build to your precise specifications.

Kinesis Aithein Disc geometry