Two topics have dominated bike launches in 2012: aerodynamics and weight. The trend towards the latter has continued at this year’s Eurobike show, where both Stevens and AX Lightness have both unveiled featherweight dream machines.

The UCI’s minimum weight limit stands at  6.8kg but advances in frame and component technology, and carbon fibre construction, have meant that bike manufacturers can build a machine which tickles the scales far below that.

That is as long as the rider has no plans to compete in an event sanctioned by cycling’s world governing body – and a lot of cash in their pocket. So, how low can you go?

The Comet SL is Stevens’ lightest ever creation and the machine took pride of place at the front of the German firm’s stand in Friedrichshafen, sat on a scale which announced its overall weight as a mere 5.05kg.

The 810g frame (claimed weight for a size 56cm) is paired with the 285g Nimbus fork from German carbon fibre specialist’s THM Carbones. That’s a super-light combination (1,095g for the frameset, available on its own for €2,599) but not out of the ordinary for a top-of-the-range lightweight frameset in the current market. The secret to the bike’s overall low weight is in the choice of components.

The Comet SL, finished in on-trend stealth black, has carbon fibre crank arms, again from THM Carbones, who also supply the carbon brakes. SRAM’s top-of-the-range Red group, the lightest from any of the three big groupset manufacturers, provides the front and rear mech, chainrings, chain, cassette and shifters.

The wheels are Xentis Squad 2.5 Tubulars, which weight approximately 1,000g for the pair, wrapped in Turbo Elite Jet tyres, while the handlebars, stem and seatpost come from Ritchey’s Super Logic Carbon range, and a Selle Italia SLR Kit Carbonio saddle completes the look.

That package will leave you with just €10 change from €10,000 – but the AX Lightness Vial will cost you another €5,000 still. It’s even lighter than the Stevens Comet SL, although only by a fraction, with a claimed weight of just 4.9kg.

The Vial is the result of AX Lightness’ ambition to create a featherweight machine which is comprised largely of components designed in-house by the German manufacturer. That, they say, allows them to assemble a machine which works as one, without sacrificing stiffness and handling.

The Vial frame (claimed weight 745g), hand laminated in Germany, is based around a BB386 bottom bracket, where the bearings are pressed directly into the frame, removing the need for an intermediate sleeve and, according to AX Lightness, providing the most direct connection to the frame, thus improving stiffness and saving approximately 35g.

This is a machine made for speed and the bottom bracket design, along with the rectangular tube profiles and asymmetrical chainstays, suggest the Vial will live up to that promise. The spec includes the firm’s own wheels, chainset, brakes, stem, handlebars, seatpost and saddle, paired with SRAM Red shifters, front and rear mech, cassette and chain.

Finally, we also spotted Ridley’s new lightweight offering, the updated Helium SL, at Eurobike. The Helium is a familiar part of the Belgian brand’s line-up but the flagship frame has gone on a diet, with the new SL (that stands for super-light) version dropping the weight to a claimed 780g.

The frame is compatible with both mechanical and electronic groupsets, while other changes include internal cable routing, a PFBB30 bottom bracket and a 27.2mm seatpost, which replaces the existing Helium’s integrated seat post as it offers a little more shock absorption and reduces the weight. The Helium SL is paired with the new 310g Helium Ultralight fork.