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Mavic : Factory Visit

Mavic bike
James Witts
23 Apr 2015

Secrets don't come easy but we've peaked behind the curtain to see the Service Course and how a Ksyrium rim is made.

The Ksyrium

Mavic spokes

Saint-Trivier-sur-Moignans is about 30 miles north of Lyon and is bathed in cycling heritage, having hosted some of the biggest races on the calendar. Stage five of the Dauphiné started here in 2012; Paris-Nice visited in 1977, as did the Tour just a few months later. That day went to Dutchman Gerrie Knetemann, though Bernard Thevenet won the overall title, the second of his two Tour victories.

The factory is a glimpse back in time – not surprising as this factory has been producing rims since 1966. At one stage, it was reported that 65% of the world’s bike rims were produced here, before Mavic spread to Romania and Asia. ‘About 90% of our aluminium rims are made here,’ says Lethenet, ‘with 10% – mainly entry level rims – being made in the Far East.’

Around 70 staff work in this large warehouse full of huge shelving units that burst from the concrete floor right up to the corrugated roof. Look a little closer and you notice those industrial shelves hold six-metre lengths of aluminium, profiled as per Mavic’s particular rim design. Mavic can claim to have perfected the art of rim profiling, as back in 1975 in partnership with Michelin and its Elan tyre, it patented the hooked rim shape that’s now the norm to seat a clincher tyre.

There’s certainly an air of proficiency as the aluminium is placed into a machine that bends and cuts it into a circular shape. ‘Always cut in a group of three and always remembering that the diameter’s going to decrease when the rim is welded,’ says Lethenet.

The two ends are then welded together. While entry-level Mavics such as the Aksium Ones use a traditional pin join, the Soudé Usine Process (SUP) of higher-end models involves hammering a rim-profile shaped wedge into the rim’s end to ensure it keeps its shape when welded together at very high temperature. The excess material at the join is then ‘deburred’, ensuring a smooth ride and no shuddering when braking.

Mavic handbuilt

‘The next step is drilling [the spoke holes], and protocol depends on the level of the wheel,’ says Lethenet. Again, for entry-level wheels it’s more basic: the rim is clamped into a large drilling machine and the requisite holes drilled. If it’s a higher-end model such as the Ksyrium SLS, it will feature Mavic’s FORE technology, developed back in 1999. Mavic worked with a robot specialist to design a tool that doesn’t so much drill the rim as push into it and create a thread so that the spoke can be screwed in.

‘By not drilling all the way through, not only do you not need rim tape, but you save weight because you don’t need as many spokes due to not losing rim strength,’ explains Lethenet. ‘Notice too that they’re not in a straight line. The rim is asymmetric to balance the tension of each spoke.’ It’s a fascinating process, albeit one we are not allowed to photograph. ‘Non autorisé.’

Mavic cosmic

The inter-spoke milling is pretty impressive, too. Within enclosed machines, precise drills and sanders shave curves into the rim walls in the spaces between the spoke holes to save weight without sacrificing rigidity. ‘You can reduce up to 10% of weight this way,’ says Lethenet. Mavic originally termed this process 2D, then advanced to 3D and, for 2015, you’ve guessed it: 4D.

‘With 4D, everything’s rounded, not just between spokes but the edges, too. It’ll be seen on the 2015 R-Sys SLR. It reduces inertia so is great for climbing. It’s also better at braking than previous models because it features our Exalith 2 technology [which improves braking power].’

Things are finished off with the graphics – stamped if top-end, stickers if not – and then they’re boxed up for either building in Romania or sent to retail to do similar. ‘I counted once, and there are over 100 processes involved in constructing a Ksyrium,’ says Lethenet. ‘This company is founded not only on innovation 
but on precision, too.’

Page 2 of 3Mavic : The Ksyrium

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Page 2 of 3Mavic : The Ksyrium