Carbon-ti X-ring Al/ca chainring
Because everything is better with carbon fibre
n the world of bicycle upgrades, carbon is king. When practically every other component on your bike has been formed of the black stuff, it only makes sense that the chainrings be next, and Italian company Carbon-ti has just the thing.
‘To start with, Carbon-ti leveraged the knowhow of its parent, LLS Titanium, a company with 27 years of experience in industrial-scale titanium and carbon fibre manufacturing,’ says product manager Marco Monticone. ‘We applied it to bike components because we recognised we could make products that were lighter and stronger than what was on offer.’
Carbon-ti’s X-ring chainring has metal teeth bonded to a carbon core, although somewhat surprisingly the metal is aluminium, not titanium.
‘Initially the chainrings had titanium teeth, but the way it had to be manufactured meant the surface area to bond onto the carbon was very small so they were very difficult to produce,’ says Monticone. ‘But research and development into aluminium meant that before long we could use a special AL7075 alloy in place of the titanium. It was even lighter and cheaper but still very durable and easier to bond onto the carbon core. The product undergoes constant refinement but broadly it has remained the same since that switch because we’re so happy with the design.’
Mixed materials
The chainrings start life as aeronauticalquality AL7075 alloy sheets and 3Kweave carbon fibre panels.
‘This carbon is key to the chainring’s attributes, but the type and orientation of the internal layering is very special and secret,’ says Monticone.
Both the aluminium teeth and carbon fibre cores are initially cut with a waterjet – a 60,000psi stream of water and fine grit – then the engagements between the two semi-finished parts are CNCmachined. ‘There are male and female parts cut in to ensure the materials bond perfectly together,’ says Monticone. The CNC machine also mills the shape of the teeth and the ramps that aid the upshift of a chain, but once that is done, everything else is finished by hand and trusted to only a few skilled craftsmen.
‘These guys bond the carbon to the alloy with a special glue, then rivet the chainring with eight small titanium rings – of course titanium had to be used somewhere – that mechanically secure the bond and facilitate gear shifting,’ Monticone says.
Each and every chainring undergoes this process, which takes several hours and is the reason for the hefty pricetag. While the finished product is certainly expensive, it’s not actually that crazy when you consider a new Shimano DuraAce 9100 54t chainring costs £220.
‘Production runs are very limited and the manufacturing process is so much more complicated than our competitors that I don’t think CarbonTi products are fairly compared to the competition, neither in price nor performance,’ says Monticone.
He’s got a good point – a 52-tooth Carbon-ti chainring, weighing in at 92g, is almost 20% lighter than the Dura-ace equivalent.