Ax Lightness rim production – here are some key engineering elements in rim construction that AX-Lightness utilises:

Seamless Brake Surface (SBS) uses high-pressure autoclaves to combine the wheels’ layers with gas, eliminating any imperfections down to the smallest edge for a one-piece brake surface that’s both seamless and virtually free of imperfections. It may look like a typical, mass-production rim, but the Ax Lightness Premium rim is nearly perfect on a microscopic scale after it’s cured, so there’s no shuddering while braking during descents. After curing, the wheels are tempered, which realigns the resin crystals to drastically increase the braking temperatures that they can withstand before the carbon softens and deforms.  Thanks to elaborate, specifically to the raw material optimised production processes and tools our rims feature a one-piece, seamless brake surface, that yields a perfectly flush brake track without the need of any further treatment, machining or fly-cutting. That way any kind of brake rubbing and stuttering is being eliminated which results in a drastically improved modulation of your rim brakes and therewith translates into a real gain in safety as well as time in races: He/she who is able to brake later, in conclusion is faster for a longer period!

Spoke Reinforcement Technology (SRT) -upon production individually casted and moulded as well as according to the occurring load specifically reinforced spoke holes eliminate the need for a post-processing, machining or subsequent drilling and therefore a weakening of the structure. In particular the area of the spoke nipples is the highest stressed part of the rim. A drilling is of the fibre in this respect technically makes even less sense. But is an accommodation to mass production (in regards to time and labour) respectively simply due to a technology-transfer of well-known manufacturing techniques from metal rims without paying respect to the specific requirements and properties of fibre reinforced materials.

Five tons of a nipple pull-through resistance. The moulded nipple seats yield perfectly hub flange orientated nipples. As a result our rims do not carry any spoke tension limit. Stress tests at an independent university test laboratory attested a nipple pull-through resistance of 5t – much more than any spoke, nipple or hub body would ever be able to bear. We use a spoke tension of 1300 N for our wheelsets and for that purpose are being supplied with specifically reinforced hub bodies from our hub suppliers that are able to cope with the high tension.

Rim material choice & production peculiarities – we are exclusively using the highest grade carbon pre-pregs with specific properties for the requirements for our rims and adapt our production processes specifically to the demands of the material in use in order to thus be able to fully exploit the potential of the raw material. That way we are using high-grade, high-tensile fibre types with a specific resin system with long curing times and adapt our processes accordingly. Whilst a rim in mass production is hardly ever allowed more than 30 minutes, our first curing cycle accounts to a whopping 2 1/2 hours and in addition features very flat temperature and pressure gain slopes. This is in order to guarantee a resin flow as optimal as possible and to ideally net the laminate layers as well as to offer enough time to press out even the smallest gas bubble in between the laminate layers. With faster curing times however the danger of even generating additional gas bubbles in the system increases due to the fast and high rising temperature. These would not be visible with the naked eye – so do not differ in quality optically – but will yield vastly worse mechanical properties; a not be taken lightly price of a quantity driven mass production.

Formula 1 materials – as material we are using a specific resin system from motorsports that offers the highest heat tolerance and mechanical robustness and there predominantly is being utilized for the thermally and mechanically highly stressed brake exhausts of Formula 1 cars.

Tempering – this no enough and especially important for rim brake rims: In addition to the actual curing all our in effect already finished rim brake rims run through another heat cycle in a separate heating oven. During this so called “tempering” the rims are being gradually brought to their glass transition temperature (T_g) in order to prepare them for extreme thermal stresses, such as dragging brakes of a heavy rider in alpine territory. In this cycle the resin crystals re-orientate and this way ensure the highest possible safety. Production time – the production of a single ax rim takes 7 1/2 hours in order to get the maximum out of the material and to be able to offer you the best possible quality and performance – a span of time that was unthinkable in mass production!

Rims: Fibre cloth vs. UD fabric? Frequently we are confronted with the question if we could produce or offer our rims as well in UD finish carbon fibre? Thanks to the exclusive in-house production, short reaction times and the option to serve customer demands as well as the constant availability of different fibre types, cloths and fabrics in-house with us, technically this would of course not be any challenge. Howsoever at the same time production in UD will impact the quality of the rims and both lower the mechanical as well as thermal resistance of the rims. So why does the majority of the competition nevertheless use UD? There are two main factors that hold responsibility:

  1. First of all it cannot be dismissed that UD surfaces momentarily are very “trendy”. After years of cloth surface on every single component more and more customers yearn for a bit of understatement and therefore welcome the subtle look of UD components.
  2. Moreover it is merely economical reasons that make the industry push the utilization of UD fabric: UD fabric only costs just one third of the price of fibre cloth!

Here are the advantages of fibre cloth in comparison to UD fabric –

Mechanically advantageous – that we produce our rims in contrast to current trends solely in cloth instead of UD has mere functional reasons. Whilst UD fabric is very well suited for long, bending-loaded components (examples: handlebars or seatposts), they are in comparison to cloth less favourable for dynamically loaded components such as rims, as the latter is able to cope with different load directions whilst UD is only able to do so in one direction, alongside the fibre. These advantages especially bear fruit in case of exterior impacts. The cloth net keeps the surface together and can cope with impacts much better than UD layers that tend to delaminate. That way the rims can be built lighter with the same level of safety and stability. A classic, abstracted example on the same basis by the way is the well-known issue of tearing off pieces of carbon upon (tubular) tire removal from the rim. Here as well forces contrary to the high-tensile direction of the uni-directionally orientated fibres occur – issues, that would not have been present with cloth.

Thermally beneficial – a further disadvantage of UD fabric is especially relevant in case of rim brake rims: The induced heat from the friction of the brake pads at the brake track can only be dissipated in direction of the fiber, the resin in between the laminate layers acts insulating. With unidirectional fabric (UD) the occurring heat can thus only be dissipated into one direction. Due to the rotation and the medium air (wind) as coolant as well as the possibly large rim surface this is mostly just enough to sufficiently cool down the rim, yet cloth yields not to be ignored advantages here as it can dissipate the heat onto a much larger surface that firstly (and in compliance with simple physical considerations) is able to cool down much faster and moreover also effectively eliminates the for the laminate dangerous “hot spots”. This is a key benefit when approaching the limit(s)!