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Interbike 2009 – Cannondale’s Simon Lefty Suspension Damping Computer

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INTERBIKE 2009 – Cannondale had probably the most technologically cool innovation at Interbike this year. Five years in development, it’s still in prototype stages but was shown as proof of concept.

Called Simon, the technology is a computerized damping and travel adjust system built into a 130mm Lefty fork. It offers 10,000 mapped suspension profiles based on XC, AM, DH and Locked Out settings. Each setting takes into account rider preferences, weight and sag, and each is customizable if desired.

Really, the best way to get a sense of what it can do is to watch the video of Cannondale’s resident riding techie (tell your kids, computer nerds can be cool, too…see what you can do with math and science?) Stanley describing his invention.

Pics and more details after the break…


Decked out on the display bike with Crank Brothers’ new Lefty Cobalt wheels with green spokes, Simon’s bike caught some eyeballs. In fact, it first caught our attention the night before our meeting with Cannondale at the bar:


That’s Daniel in the blue shirt trying to distract C’dale’s expo supplier, who was guarding the bike. Despite a few beers, we couldn’t talk him into letting us ride it down the escalator.


Externally, the Simon system consists of the screen, joystick and a sensor at the bottom of the fork. The entire system with fork is 4lbs for a 130mm fork. Likely, the battery is what’s weighing the system down…it fills most of the headtube. For comparison, the Lefty Max Carbon weighs as little as 2.83lbs with 140mm of travel.

Battery life is estimated at up to 8 hours (or as little as two with constant bumps in lab testing), so it’s likely good for two or three rides before you need to recharge the 14.4v Li-Ion battery pack. For 12- and 24-hour racing, you’d simply buy a few extra batteries and swap them out during a pit stop, but for 99% of rides, it’s looking like a big stick of awesome.


Internally, the electronically controlled oil damper is what makes the magic happen. Made by Enfield Technologies, it’s a far cry from Cannondale’s ELO (Electronic Lockout) system from years ago. It’s essentially a twin tube damper that uses only a single orifice for oil flow. The retractable pin can go from full open to fully closed in just 6 milliseconds. This gives the fork the ability to be fully locked out but react to big hits instantaneously with full suspension performance before returning to lockout…and it’ll happen so fast, you won’t even feel the harshness of hitting the bump. Contrast this with current lockout/blowoff systems where the bump has to push through a physical blowoff valve before opening up, and Cannondale’s system is lightyears ahead of the game.

The stepper motor is estimated to last up to 30 million cycles before it needs replacement, and any updates can be made through the computer without having to change out any internal parts.


The Simon computer screen shows the five settings:

  • XC – Subtle damping for crisp performance
  • AM – Wide open oil flow for soft, bump eating performance
  • DH – Wide open travel with big ramp up at end to prevent bottom out on big hits / drops
  • TM – Travel Management: Compress the fork to a preset travel level for climbing, then hit the button to return to full 130mm
  • L/O – Lock Out: Users can set the amount of pressure required to open the valve, allowing anything from a very stiff lockout to opening at the slightest bump.

The various travel and damping performance levels are all due to the computer’s and motor’s ability to actively and instantly change the oil flow within the damper, allowing platforms, bottom out and top out performance anyway you like it.

The Travel Management feature is something that Lefty forks have lacked until now (or at least until Simon is actually released). Because it’s controlled with damping and the computer, travel can be adjusted from the full 130mm all the way down to 30mm. Regardless of how short you set it, the travel is as fluid as when it’s set at the full 130mm. Set the lower level on the computer, tap the joystick left and push the fork down and voila, a short travel fork. Tap the joystick again and it pops back up to full travel.


Initial set up is super easy. Just thumb through the menu to enter your weight and preferred “feel” and the computer will give you an ideal air pressure. Then, air up the fork, sit on the bike, and the computer will measure actual sag versus recommended sag and advise on how to correct it (more or less air pressure). Changing your riding preference either firmer or softer changes the recommended air pressure.


The accelerometer can detect movement faster than you can, making the ride on the Simon Lefty plusher than any mechanical platform fork can ever be.

So, how much is it? When can you get one? Don’t know, and Cannondale’s not even venturing a guess other than to say it’s very expensive and that likely one or more parts of this system will trickle down into future products even if the complete system doesn’t show up on your bike shop’s floor anytime soon.


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14 years ago

Great idea, but there’s alot of Cannondale haters out there,
so if they really wanna make money, they should license the technology to Fox, and Rockshox.

14 years ago

Yeah, I wonder what Cdale spends on marketing each year.

looks something like this: http://www.sciencenews.org/sn_arc97/11_22_97/vibe2.jpg
re-birth of the old Girvin battery powered / controlled fork.

or even some of this technology:

copper coil with a rod and magnet and a bit of electronics to control the rod.

14 years ago

Oh, my god! When are these stupid bike manufacturers going to get it? You don’t need a freakin’ computer to ride a bike, and all this is doing just slowly sucking the fun out of biking and turning it into a cold, soulless abyss controlled by computers. Geez, this is exactly like Will Smith’s nightmare in I, Robot! I love Cannondale, but this is bleepin’ stupid!

11 years ago

I think that this is great technology and cannondale haters can paint their bikes blue and throw them in a lake cannondale is a bike company and is much more innovative than all suspension companies together
Cannondale Simon may not be very light and it is very expensive , but never mind
It’s the best fork technology out there !!

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