Light, stiff, aerodynamic, comfortable and durable – A2J from Sweden did not design a bike to excel at one of these metrics. The ‘lean Swedish company designing and manufacturing front line bikes’ wanted to build a frame that would be outstanding at all five, simultaneously.
A2J’s R frame features:
- Full internal wiring (complete with fully hidden bespoke lightweight battery option) for both mechanical and electronic shifting;
- Modern geometry and aerodynamic architecture;
- One of the highest stiffness to weight ratios available; and
- A guaranteed maximum frame weight under 850 grams for a size 56 including headset, seatpost clamp, front derailleur bracket and rear derailleur hanger. The frame is designed for a rider weight limit at 150 kg.
To achieve its ambitious goal A2J undertook a number of steps…
‘Firstly, we assembled our development dream team, ensuring we had all the available knowledge to deliver a class leading design. With the team’s experience and backgrounds, we had ready access to the most sophisticated and advanced computer aided engineering (CAE) and a thorough understanding of the most advanced composite materials and resin systems. Our first decision was to make a monocoque frame rather than tube to tube because of the freedom and customization options it would afford us. We had a clear understanding of how to develop the frame’s structural requirements that would primarily be geometry, not materials driven.
‘Among other things, this choice allowed us to optimize the frame’s sectional and transitional geometry as well as the lay-up and thicknesses, placing material where needed, giving us freedom to tune our pre-determined metrics. This also allows us to tune the metrics and ride characteristics to personal specifications. A personal frame tuning service is therefore available for the most demanding clientele.
‘With the monocoque frame decision made, we set about the aerodynamics. Our frame was not designed specifically to be an aerodynamic frame but our aerodynamics engineer spent around a hundred hours on a supercomputer optimizing the sectional geometry. We have been able to achieve a frame with a significant watt savings over a conventional round tube shape. The CFD numbers will be verified in the wind tunnel with a rolling floor, a real rider and fully equipped bike later this autumn/fall.
‘The frame’s carbon layup system is based on a mix of UK company ACG unidirectional and twill prepregs with resin-weave system and Swedish company Oxeon’s Textreme weave. The 3 piece frames are made by hand, laid over a preformed bladder into polished aluminium and carbon clamshells and baked in an autoclave in Linköping. Thomas Mertin from THM is overseeing the layup correlation testing at its facilities in Alt Duvenstedt, Germany. Finished frames are being tested at Zedler Institut für Fahrradtechnik und -Sicherheit in Ludwigsburg, Germany.
‘As part of the initial specification, our engineers designed the frame to include complete internal cabling, which needed to work with both mechanical and electronic shifting., as well as integrated sensors, internally packaged battery pack and an in-house developed and patented e-shift control system.’
A2J does not paint its frames as standard… ‘We feel it is a shame to hide the artisan craftsmanship required to create each frame, however if you prefer a paint finish, we can of course tailor a bespoke colour scheme for you and our master painters will execute a top class durable finish.’
The company manufactures entirely in Sweden, by hand and to order. The company will be at Eurobike on the THM stand in Hall A2, stand 205.