Gear News

Kinesis Racelight Aithein road bike – first look

Kinesis UK, the creative outlet for designer Dom Mason, has carved an impressive niche with its aluminium bikes.

The ubiquity of cheap carbon frames has lead many – wrongly – to look upon aluminium as a poor relation to composite frames. Aluminium, however, is making a comeback in the hands of experienced designers like Mason, who told this site that working with “soulless” carbon holds no interest for him.

The Kinesis Racelight Aithein

Following the success of the Racelight TK3, a four-seasons bike embraced as the RCUK Winter Bike and now as our test rig, Mason has released the Aithein, a machine designed to take aluminium frames to another level and set to be the brand’s flagship ‘race frame’.

Performance Aluminium

The Aithein’s design reinforces what many experienced racers already know, which is that a good aluminium frame is often better than a carbon one for the same price.  Where riders are drawn to carbon as a material for its stiffness and lightness, many are recognising that the reality at the budget end of the market in particular can be disappointing. What’s more, the geometry of frames at the entry level tend towards the so-called ‘sportive’ style, with longer head tubes and slightly relaxed angles to allow for a more upright ride.

Instead of wading into this overpopulated domain, Kinesis have taken what they already know in producing high quality, good value aluminium frames, and invested their design and development in this new ‘racier’ model made for speed and sharp handling, taking on as many of the superior design features of contemporary carbon frames as possible, but using aluminium.

Super Plastic Forming

The manufacturing process that makes this possible is the patented technique for shaping aluminium called Super Plastic Forming (SPF). This high temperature process ‘plasticises’ the alloy and uses pressurised gas in the mould allowing for more complicated and controllable shaped tubing than the hydroforming process that was its predecessor.

The Super Plastic Forming process from which the Aithein’s aluminium chassis is formed allows the use of many design features of contemporary carbon frames, such as the tapered headtbube

This offers the designer the opportunity to subtly shape the frame and more closely monitor thickness, resulting in a stiff and light alloy frame.

Subtle shaping, classic look

Mason explained the thinking behind the shape of his new frame, one that has been almost two years in the making. Central to the design is the seat tube, which Mason describes as the ‘core’ of the frame, providing stiffness around the bottom bracket area when the rider is out of the saddle, climbing or sprinting. The strength provided in the seat tube allows the other tubes to be shaped to be somewhat lighter.

Mason describes the seat-tube as the ‘core’ of the Aithein. Its strength allows the other tubes to be somewhat lighter

The down tube is ovalised at the BB end with a triangulated section at the head tube, providing lateral stiffness, and reinforcing the rigidity at the bottom bracket. The head tube tapers from a broad lower bearing, home to a monocoque carbon fork, again for added stiffness. The top tube follows a traditional design, as do the seat stays, straight rather than curved, and designed to give instant feedback from the road when climbing, sprinting and descending.

The tube profiles have been carefully considered to provide a snappy, responsive ride, which together with race-ready geometry and a classic look makes the frame an attractive prospect for adventurous riders seeking a chassis for around the £700 mark.

Weighty issues

Weighing in at just over a 1kg for the frameset (depending on size), the Aithein is slightly heavier than some of its carbon compatriots, but we expect its other qualities to close the performance gap. Providing a more robust frame with greater longevity, Kinesis UK hope to challenge a market dominated by ‘disposable’ carbon frames by offering something a little different for the more discerning ride, and at a competitive price.

The Aithein’s claimed frame weight of just over 1kg, depending on size, makes it slightly heavier than upscale carbon offerings

The Aithein is sold as a frameset only, and money saved on a more expensive carbon chassis could be invested in a more upscale groupset or lighter wheelset than might otherwise have been afforded. Our test sample is perhaps a good example, equipped with a frankly immodest Shimano Dura Ace 9000 groupset and Reynolds 32 carbon hoops.


The only equipment limitation to this frame is that it is not suitable for Shimano Di2 (except with external cabling). Drilling the chassis for internal routing of the necessary cabling was considered a compromise to the Aithein’s integrity by the Kinesis UK team.

Since there is no compromise on weight in the frame either, they also make the conservative recommendation that is suitable for riders of 14 stone or less, and 59cm is the largest size which the Aithein will be made available. Rather than being a negative feature, this refreshing approach allows lighter riders to maximise their advantage, and will likely make the frame very appealing to smaller riders, including women.

On paper the Aithein looks like a genuinely ground breaking toy for throwing around the local lanes after work, or testing out at your local crit.  We look forward to seeing how it handles out on the road.  Check back soon for a full review.

Discuss in the forum

Website: Kinesis UK
Distributor: Upgrade Bikes
Price: £649.99
Sizes: 47, 50, 53, 56, 59


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