First Look: SRAM / Avid XX World Cup Brakes, Plus Cutaway Views of Taperbore Tech

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Shown today at SRAM’s press camp for the first time is their new Avid XX World Cup disc brake lever. It shares the forged magnesium piston body as the original XX brake lever, but loses the pad contact adjustment to save additional weight.

While the caliper stays the same, the lever body drops about 15g to bring the brakeset (front, 160mm rotor, post-mount) in around 270g per wheel. The lever blade remains carbon, and the reach adjust is via a small hex key under the pivot.

More pics of the set, plus some cutaways that show how Taperbore works versus traditional hydraulic disc brakes and how their pad contact adjustment works, after the break…

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Each set comes with Avid’s Pad Spacer, which conveniently doubles as a bottle opener.  Look for the new Avid XX World Cup brake levers to start showing up on pros’ bikes in the next couple World Cup events, and full production starts around August. No specific release date is set, but look for them near the end of the year.

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Ever wonder what the difference between Avid’s original Juice design, which is common amongst other brands, too, and their Taperbore?  Here’s the deal: Shown above is the original Juicy design with the reservoir on top of the plunger. When the lever is out (not braking), oil flows through the timing port to handle expansion and keep pads in the right place as they wear. As you squeeze the lever, the plunger seal passes the timing port and closes the oil into the hose. As you continue to pull the lever, the plunger pushes the oil into the hose, which pushes the pads closer to the rotor.

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With Taperbore, the reservoir surrounds the piston. When the lever is open (not braking), the plunger seal sits in a slightly larger diameter “pipe”. Once you squeeze the lever, the plunger seal moves further into the pipe, which tapers quickly down to just slightly smaller than the seal’s diameter. The seal deforms slightly to create a tight seal in the pipe, thus closing the oil within the hose and pushing it down to the caliper and pushing the pads toward the rotor.

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For brakes equipped with the Pad Contact Adjustment, the tapered “pipe” resides within the adjustment bezel. As you twist the bezel, it moves the point where the plunger seal closes the oil in the hose further or closer to the seal, thus changing the point within the lever pull that the pads make contact.

The screw that’s in the bezel is the bleed port.

Comments

joseph grimes - 06/20/10 - 11:41pm

tyler – were you in chicago or colorado springs for this media camp?? the stuff looks good!

[...] above are modified versions of the new XX World Cup brakes that SRAM just unveiled at their press camp. Astute readers may notice the addition of the anodized red reach adjust knob. [...]

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