ergott
08-21-2007, 12:16 AM
David Millar (Saunier Duval-Prodir) had a disastrous ride during Stage 19 of this year's Tour de France. Almost immediately after catapulting himself down the start ramp, Millar's disc wheel failed catastrophically, but thankfully, the Saunier Duval-Prodir team mechanic was at the ready with a spare bike. Unfortunately, though, that machine suffered the same fate just a few meters up the road, laying waste to Millar's aspiration for a TdF stage win on a course that suited him nearly perfectly.
Millar was using a prototype Carbon Comete rear disc wheel from team sponsor Mavic. As compared to the existing Comete, this new model was said to be substantially lighter, at least partially due to the use of a lighter aluminum rim extrusion. Upon further examination of the race footage, it became obvious that Millar's wheel failure came about as a result of a complete separation of that bonded rim section from the disc on both occasions.
Sean Sullivan, Marketing Director for Mavic Inc., confirmed the failure mode. "David was using a prototype Carbon Comete [that was] much different and lighter than a regular stock version. I'm told the extrusion totally separated from the carbon flanges of the disc wall. At this time it hasn't been determined exactly why it happened, but it was some sort of failure of the bond between the surface of the aluminum extrusion and the inside of the carbon flange."
"While a lightweight prototype, I don't think the occurrence was necessarily from any new technologies that were used," continued Sullivan. "It just appears to be more of a freak isolated incident with the preparation of the surfaces or the bonding process on his particular wheel and not a common failure with our competition prototypes or our production Cometes. Mavic prides itself on the quality and durability of our products and while we like to push the limits of technology for our racers' benefit, we would never put any racer on a wheel that we thought might have a catastrophic failure of this nature and it's horrible that it happened."
Mavic apparently places at least some blame on the initial shock from the starting ramp, but that does little to explain the second failure. According to Sullivan, "This incident happened right out of the start gate after the slight impact from hitting the pavement off the start ramp, which then uncovered the flaw in the bond in this particular wheel. David rode the same wheel with no problems in the Prologue. It's terribly unfortunate for David to have this happen during such a critical stage of the Tour on a day where he was sure to do very well."
It's funny because it happened twice.
:D
Millar was using a prototype Carbon Comete rear disc wheel from team sponsor Mavic. As compared to the existing Comete, this new model was said to be substantially lighter, at least partially due to the use of a lighter aluminum rim extrusion. Upon further examination of the race footage, it became obvious that Millar's wheel failure came about as a result of a complete separation of that bonded rim section from the disc on both occasions.
Sean Sullivan, Marketing Director for Mavic Inc., confirmed the failure mode. "David was using a prototype Carbon Comete [that was] much different and lighter than a regular stock version. I'm told the extrusion totally separated from the carbon flanges of the disc wall. At this time it hasn't been determined exactly why it happened, but it was some sort of failure of the bond between the surface of the aluminum extrusion and the inside of the carbon flange."
"While a lightweight prototype, I don't think the occurrence was necessarily from any new technologies that were used," continued Sullivan. "It just appears to be more of a freak isolated incident with the preparation of the surfaces or the bonding process on his particular wheel and not a common failure with our competition prototypes or our production Cometes. Mavic prides itself on the quality and durability of our products and while we like to push the limits of technology for our racers' benefit, we would never put any racer on a wheel that we thought might have a catastrophic failure of this nature and it's horrible that it happened."
Mavic apparently places at least some blame on the initial shock from the starting ramp, but that does little to explain the second failure. According to Sullivan, "This incident happened right out of the start gate after the slight impact from hitting the pavement off the start ramp, which then uncovered the flaw in the bond in this particular wheel. David rode the same wheel with no problems in the Prologue. It's terribly unfortunate for David to have this happen during such a critical stage of the Tour on a day where he was sure to do very well."
It's funny because it happened twice.
:D