Tuesday, July 6, 2010

Drank the Kool-Aid and liked it...

I first got intrigued with the Lefty after doing a quick parking lot roll on a 2009 Cannondale Caffeine conveniently parked in the bike rack at our local bike shop; Bikeworks.


The dampening action seemed smooth and responsive and the dual crown front end seemed solid. So I did a little reading on this thing called a Lefty and I became more and more impressed.

No seals to cause "stiction", just 88 smooth rolling needle bearings supporting the travel with a Rock Shox Cartridge Design for dampening. A "25mm to 15mm" Tapered Roller Bearing front wheel hub provides a smooth rolling wheel with lots of rigidity. And a carbon design makes it really light. Like 2.5lbs light!!!

So I decided to take a chance and swap out my Reba on the Orbea Alma 29er Race Rig with a Lefty. I found a deal online for a 29er ready fork and contacted the folks at Project-321 to procure a wheel hub and a 1 1/8" steerer tube. A little magic wheel building by Dan "The Man" Swinton and yes, some fussing and fidgiting, and low and behold, I have a Lefty on my Orbea.


So what's the bottom line here Goat, you may ask? Well first off I dropped a whole pound off the bike. I went from 23lbs-10oz down to 22lbs-10oz, right off the bat. Not bad! I also lost 20mm of travel from 100mm down to 80mm for the Lefty. But the Orbea is a Carbon HT Racing platform that is designed around an 80mm travel fork, so no sweat there. The Axel to Crown dimension did change by 20mm, so the geometry was impacted.

Now when I rolled out the other night on my initial ride, the first thing I noticed was this change in geometry. I had gotten use to the 100mm Reba and with the Lefty I could feel that I was weight biased on the front wheel a bit more and felt a little more on top of it. Not a bad feeling mind you, just different. I was wondering how that would impact the feel of the front end; the stability, the control and the dampening. So I took note and off I rode.


The first thing you notice about riding the Lefty is it's solid feel. The dual crown design and the large diameter strut combined with the square shaft/needle bearing design are rock solid. I could detect NO flex what so ever in the front end. Definitely more solid than the Reba or the Fox 29er I've ridden previously on this bike.

Those who know me, know I am a real believer in "dual crown" XC forks. Going back to my experience with the early days of the Maverick DUC 32 and up to my current favorite all-around trail bike, the Spez Enduro SL, I have always felt that a dual crown fork is way more rigid and solid than any oversized 1.5" or tapered headtube will ever be. And the Lefty just re-affirms that belief in my world. If I have an option, I'm going dual crown!!!


The geometry change did liven up the response of the steering, but I wouldn't call it hyper-active or twitchy. In fact, I think the solid nature of the fork actually compliments rather than counteracts the "responsiveness" of the steering. You can literal put this bike where you need it at a moments notice and not have it go swinging it's head in reluctant disregard. It is very confidence inspiring when you know you can truely point and shoot. Combined this with the "demands" that a 29" front wheel places on the handling and I think its a winning combination of strength, response and traction.

So the handling is great but what about the dampening. This is where I think this fork really shines. The needle bearing design and lack of seal stiction come together on the trail in a very real way. Almost instantly I could feel the response of the fork to small bumps and trail undulations. It's almost hyper-sensitive to trail input in a way that is surreal. You actually feel all of the nuances of the ground below you. It "ground tracks" in a way I have never felt on another fork. The best way I can describe it, is that with conventional seals and stiction there is a delay in feedback from the trail to your hands. This delay causes a lack of connectedness that can be interpreted as poor small bump compliance and feedback. With the Lefty's design its like a veil has been removed from the reponse to the trail and you are now in a hyper-aware mode of judging the traction and response of the front end. It really is that significant!!!

So how does the dampening feel? Well it uses a proven design in the Reba Cartridge Technology but they actually take it one step further. Maybe some would call it a limitation, but I actually think of it as added simplicity. With the Reba you can add Negitive and Positive air pressure to not only change the spring rate (rate at which the fork stiffens up under compression) but to also change the initial ride characteristics from firm to plush (slow speed compression dampening).

With the Lefty they have combined the Negative and Positive Pressure adjustment into one valve. So you don't have as much adjustability, but it is simplier to set. In effect they have taken a middle of the road approach to setting the folk dampening and they seemed to have guessed(?) pretty well where that is at. I put 120PSI into the fork for my 175lb weight and the fork rode somewhat firm, but ate up all of the admittedly limited ruggedness of our North Foothills trails. To challenge it a bit, I threw some "Bunny Hops" off of ledges to flat and the fork compressed well, ramped up smoothly all without bottoming. In other words, it felt pretty spot on which is a testament to how much design and development has gone into the Lefty over the 10 years or so that Cannondale has been developing this thing.

Now you may wonder, with the reduced travel and the forward weight bias, did I ever feel like I might go over the bars? Did I feel the fork might have limitations on what it could absorb. I didn't push it that far, but I never got that feeling.

I ride pretty smart so I know how to keep the front end from getting over whelmed. Not that I never endo, but for the riding I would do on this rig, I wouldn't say the fork would be a limitation. It ramps up smoothly and feels pretty bottomless. It's interesting because if you do the "Handlebar Push" test, you might think the 80mm fork travel would be a limiting factor. This is something I was initially concerned about. But when you are on the bike with your weight balanced, the fork travel really isn't something I would consider an issue.

So what is the REAL bottom line? I have a bike that is a full pound lighter than before. I can feel that weight reduction when I ride; the bike is livelier. The handling is more responsive and much more solid than before. The fork dampening has a much improved tactile feel and ramps up in a smooth progressive manner. Bottom line? This is a modification that has tranformed the way I feel about my bike.

I didn't go into this with some sort of Lefty bias, but more of wondering what it would be like. All I can say is it has proven to be one of the best modifications I have ever done to a bike. That's how strongly I feel about this.

Next up will be a conversion of my Titus Racer-X 29er with a Lefty 130 PBR stepped down to 100mm. It will be interesting to see how a Full Suspension Lefty 29er feels!!!

If you want to get another perspective of the Lefty, read the AngryAsian's Bike Radar Review. Never thought I'd see a Lefty on a Trek!

Now get out there and ride!!!!

1 comment:

Stevers said...

Great looking conversion! I'm looking to do the same on my Orbea Alma 29. Glad to hear that it stiffened up the front end without adding any weight!

Which Project 3-2-1 steering adapter did you get? I'm guessing it's the "standard fixed" adapter?

Thanks,
Steve