2011 Lefty Headshock Forks – Travel Changes and New Rockshox Bits
For 2011, Cannondale seriously revamped their Lefty forks. Travel has changed for both the Speed and 29er models, and they’ve partnered with Rockshox to develop new compression and suspension settings to accommodate users that felt older models were too soft.
With Lefty, you’re getting a 1.5″ headtube, a 25mm-to-15mm axle and dual-crown design, all of which Cannondale says makes for a far stiffer fork than traditional forks with two legs. They also say it’s smoother: Its square stanchion with needle bearings creates a mechanical movement rather than bushings that can wear and develop play and have far more friction. The roller bearings also maintain smoother movement under rotational and off-angle forcesâ€¦which could better control and traction under hard braking and corning. In our test ride on the new Scalpel, despite having reduced travel, the Lefty fork did handle XC-type trail bumps, rocks and chatter with aplomb. The older, “softer” models made the forks feel incredibly smooth in parking lot tests, but enough riders complained that they would blow through their travel too quickly on the trail. To remedy this, the compression damping is firmer all around, which makes them feel slightly less smooth when just pushing on them standing still, but the results seemed to justify the means.
There are two versions of Lefty available, PBR and XLR. Check them out with specs and weights after the break…
First, the Lefty’s now use Rockshox’s Solo Air design, allowing for a single air input to set both positive and negative chambers. This simplifies set up, but takes away the ability to fully customize the feel of the fork.
PBR – Push Button (Lockout) with Rebound. They use sealed cartridge damping, keeping the air and oil separate, which is what Fox has just done with their new FIT cartridge.
XLR – New model with Rockshox X-Loc hydraulic remote lockout (X-Loc and Rebound). Introduces blowoff on their lockout design. Previous Cannondale lockouts were totally locked. New design builds in a blowoff that will bypass the non-adjustable threshold externally. The amount of force required to blowoff is internally adjustable. The Floodgate knob on the remote is used to set the blowoff on Rockshox’s forks. With the Lefty, though, it’s non-functioning and is just used to remove air. Cannondale is working with Rockshox to create one without the barrel to shave a few grams.
CHANGES IN ALTITUDE
The 2011 Speed Line drops from 110mm to 100mm to be more XC oriented. For 29er fans, travel is bumped up from 80mm to 90mm.
29er Lefty is the actually their 120mm 26″ version that’s revalved for 90mm travel, so it shares the same weights shown below.
While travel has gone down, the low weights help you go up. Lefty’s are generally the lightest front suspension option, and with Cannondale’s new Lefty For All program, you can install them on most any bike.
The lowers on alloy models are 3D forged as one-piece, which saves about 60g over the 2009 model.Â The upper is now one-piece on alloy models, too, which saves about 100g over the 2010 model. For 2011, they have a new one-piece stem (OPI, shown above) that’s extruded and forged, then a mandrel is driven through the steerer tube to drive out the center part and hollow it out (not machined!). All told, it reduced the total exterior parts from seven to three and it dropped weight and improved stiffness.
Next gen 2011 OPI stem builds in 15mm of height adjustment. To adjust it, you’d use a Shimano BB tool to thread the lower half of the steerer tube into the top half, and 5mm spacers fill the gap to keep it tight. It’ll be available in -5Âº and +6Âº in 90, 100 and 120 lengths.
PBR dampers are internally tunable, and you can send your fork in and have them tune it. You can swap between PBR and XLR controls on the top of the fork leg. Previous models were under damped on the compression side. For 2011, they’ve built in a new low-speed compression check valve. Models will ship with a 2.0 (hole size) valve, but other sizes are available, or it can be removed to speed up compression like their older models. You can also adjust air volume to change the progressivity by adding or removing chips (spacers) to the bottom of the air chamber by simply removing the lower cap on the fork. Add chips to create a smaller air volume and it’ll ramp up faster, making it more progressive.