Trevor! said:
Whats the point of having a bar wrapped in carbon exactly? You could save more weight by taking the carbon weave off....
I assume the carbon is merely for aesthetic purposes?
Same thing to mix construction of any part with carbon, you get a stronger part without the penalty of the catastrophic failure when one material finally lets go (and you get a warning sign if the outer material fails first). Years ago during a handlebar test bicycling mag did, they tested the rocket science Wingz bar, which was 6061T6 Al outer bar with a carbon fiber core (the Titus Exogrid frame tubes use the same idea), and the Al outer after 5,980 cycles of their fatigue test, and the carbon failed at 15,730 cycles. The impact failure of the bar in the drop test was 350 pounds. This in a 125 gram flat bar that cost $80. No other pure Al flat bar in the test was as light and the ones closest in weight failed a LOT sooner. Heck, two of the heavier ones (both 144.2 grams), the Scott AT-1 LF (7075T6 Al) and the Specialized Team bar (2014-T6 Al) both did worse in the fatigue test (7,663 cycles for the Scott, 11,767 cycles for the Specialized) and while the Scott did better in the droptest (490 pounds), the specialized did not (280 pounds). The Zoom 170 bar which the heaviest bar in the test, was made from 6061T6 also, weighed 161.6 grams, lasted only 7067 cycles, and only took 315 pounds to fail.
These days, the reason for an Al core with a carbon outer, in handlebars at least, is Al better resists crushing pressure from clamping things to the bar, so it provides an reinforcement for the carbon. All sorts of handlebars have had Al inserts for the bar ends, and in this case, the whole bar gets an Al insert as it were.
You couldn't actually save more weight by ditching the carbon since the carbon has a significantly better strength to weight ratio, than any Al alloy currently in existence. The only way certain "euro" boutique brands turn out stupidlight Al bars is with VERY thin butting sections and a lot of blind faith that they won't get sold in a country where the courts love to blame the manufacturers for failures (USA for example). There's no way in hell some of those bars would ever survive any sort of real testing like bicycling did 10 years ago. Even Easton wouldn't attempt to market an Al bar that light, and they've got more knowledge in aluminium manipulation than anyone in the business. This is why the lightest bars, riser or flat, are made from carbon fiber.
