Technology

#1

CUSTOM FIT & GEOMETRY

Geometry_cropOur baseline frame design has been constructed using advanced CAD and simulation tools with a parametric CAD engine, this allows us to quickly input your fit and ride requirements and output a design in an automated process.

Due to our unique construction method all of our frames are configured to your specification – simply input your height, inside leg and arm span into our Geometry Engine here and you will receive an email outlining your recommended geometry.  From there you can proceed to place an order, or you can contact us to discuss possible tweaks to the suggested geometry based on your personal preferences.

#2

DW6 SUSPENSION

dw6-logo

The dw6 suspension design represents the latest evolution in modern mountain bike suspension. Essentially, the design takes everything that’s great about the 4-bar dw-link design, and adds further tunability to meet the goals of a custom designed experience that RBC aims to provide. The 5th generation dw-link anti-squat performance is there, along with independently tuneable braking and leverage ratio characteristics. This offers a nearly unlimited level of adjustability from the factory. dw6 is a true design for the future, and one that will be constantly adjusted and improved to take advantage of the latest in damper technology and rider preferences.

 

dw6 is not just about suspension performance though. Structurally, the design was conceived from the ground up to work in unison with RBC’s titanium lugged construction, which utilises additive manufacturing. Stiff and compact links attach via angular contact bearings at critical points for long-term maintenance free performance in even the harshest conditions.

#3

OVERALL FRAME ARCHITECTURE

Architecture_explodedWe take the best characteristics from aerospace titanium and carbon fibre materials to provide you with a strong, resilient and lightweight frame. In short, composites work well when shapes and loads are simple – a wing spar for example. Metals work well in areas of high shape complexity and when loads come from different directions – aircraft landing gear for example. To take advantage of these fundamentals we put high strength to weight ratio titanium in the areas of maximum stress and connect these together with high stiffness to weight ratio carbon composite tubes. Then we move the joint away the area of peak stress and employ a state-of-the-art double lap shear joint design.

#4

TITANIUM ADDITIVE MANUFACTURED LUGS

Full-build-plate-2By adopting this cutting-edge manufacturing technology currently being implemented in the aerospace industry by the likes of Airbus and GE and widely used in Formula 1, we have the design flexibility to create custom geometry frames, and the ability to create innovative joint interfaces.  Titanium (aerospace grade Ti6Al4V) gives the optimum strength/weight solution for these loaded areas of the frame, and works fantastically well bonded to carbon fibre laminates. In partnership with the engineering company Renishaw, our lugs are batch processed by Selective Laser Melting, with Ti powder particles in the 10-45um range fused together by a high power fibre laser, heat treated for optimal mechanical performance and then CNC machined for bearing, headset and bottom bracket fit. Our ‘double lap pi joint’ design is made possible by this manufacturing process, along with the ability to make every lug set bespoke to order. This manufacturing technology should not be confused with other technologies commonly referred to as ‘3D-printing’. We are using the same Laser Powder Bed Fusion Additive Manufacturing technologies as described is the draft SAE standard AMS 7003 in development by Airbus, Boeing, GE and Rolls-Royce amongst other to control the manufacture of safety-critical aerospace parts.

#5

FEA & Topology Optimisation

robot-bike-tech-spec-6-cropTopology optimisation is a mathematical approach that optimises material layout within a given space, for a given set of loads and boundary conditions, to provide the lightest weight design possible. Topology optimisation is a perfect fit with Additive Manufacturing, as the optimised design concepts generated can now actually be manufactured. Furthermore the maximum loads in the material can be controlled to avoid stress-raisers and employ a principle called ‘infinite life design’. The results of this are quite subtle in most areas of the frame as the ‘boundary conditions’ are quite high. For example the headtube lug needs to accommodate round carbon tubing, fit a round headset and not fill with mud – what is less apparent is the fine control over the wall thickness, which has been optimised to achieve a lighter weight. The most apparent result of topology optimisation is the chain stay yoke, where the design is much less constrained. The market leaders in topology optimisation software and its use is Altair. This approach, in partnership with Altair, has been used by Robot Bike Co. to ensure that our frames are lightweight and will avoid metal fatigue, meaning that we can offer a lifetime warranty to the original owner and a frame that will be great to ride and enduring.

#6

CARBON FIBRE TUBING

robot-bike-tech-spec-300Carbon fibre reinforced polymers work considerably better when the fibres are kept in close alignment to the loading direction. A deviation of just 0.25 degrees (~4 mm in 1m) reduces compression strength by 1/3. We use aerospace-grade Mitsubishi-Rayon TRH50/NB301 and MR60H/NB301 pre-preg materials and uniform shapes to guarantee fibre alignment, both in in-plane and out-of-plane orientations, for maximum strength and stiffness. The lay-up schedule for each tube and fibre is proprietary and specific to each tube to ensure that each tube is optimal. We avoid sharp corners, such as those found in square section tubes, as these lead to ‘corner unfolding’ when the composite is loaded through-the-thickness rather than in the plane of the fibres. Our approach means that we utilise 100% unidirectional fibres and not woven fabrics as we believe that performance is more important than what is perceived to be the ‘carbon look’. The result is our tubes are as strong and as stiff as they can possibly be, giving you a lighter more resilient frame.

#7

DOUBLE LAP SHEAR JOINTS

robot-bike-tech-spec-7aDouble lap shear joints, sometimes called pi-joints due to their similarity in shape with the greek letter π, are used on Robot Bike Co. frames. Pioneered for use in aircraft construction by Lockheed Martin, double lap shear joints are the best joints to avoid ‘out-of-plane’ loads and therefore ensure maximum joint reliability. The use of Additive Manufacturing means that higher aspect ratios and thinner walls with much greater control over wall thickness tapering can be achieved than if machined or cast. Pi-joints also allow for the use of the ‘insertion-squeeze-flow’ method of bonding to ensure an even surface coverage of the aerospace-grade two-part epoxy Henkel adhesive used. Aerospace surface preparation practices combined with our design and Additive Manufacturing process means that Robot Bike Co.’s joints are more efficient than any others known to be use in aerospace or Formula 1 applications. For you, this means the lightest weight and most reliable frame possible.

#8

Structural Testing

Test1Robot Bike Co. has employed aerospace ‘test pyramid’ methodologies to the structural validation testing of the frame. Starting at the ‘coupon level’ small test pieces have been tested by aerospace test-house Exova to provide material data to feed into the Altair software.  Next at ‘element level’ the double lap shear joints between the lugs and tubes has been tested.  Then at ‘component assembly level’ the full frame is tested to ensure compliance to EN ISO BS4210-6:2014.  Loads described by international standards are, in fact, much kinder than those we design against, so finally the frames are built up into bikes which are ridden hard by a World-Cup level test rider.