King of the Mountain

Full Floater Explained

Welocme again to Suspension 101. For this lesson, we're joined by Jose Gonzalez, as he can really explain how the Full Floater suspension really works, what its benefits are, and how it compares to the competition.

Full Floating Suspension - What is it?


Fullfloater_actionarrows2_k The Full Floater works in conjunction with the EVO Link and the shock to create a suspension ride with unparalleled tuning and performance. Instead of simply mounting one end of the shock to the rocker link and one end to the frame, the shock is held in a suspended state between the rocker link and a mounting point attached to the swing-arm. The shock “floats” on two suspended attachment points.

What is the Benefit?
The Full Floating suspension design allows the suspension system to be tuned more highly than ever before. The suspension system is tuned to work in harmony with the specific shock spring technology (air or coil) through-out the entire range of suspension motion.
What this creates is a suspension that is incredibly supple and active on small bumps, has excellent control through the mid-stroke, and has a gentle progression at the end of the stroke to handle big hits and drops.
However, this progression has been very painstakingly tuned to get the perfect balance of allowing full travel, without blowing through the travel too easily.
All this comes without compromising the legendary ride of R1 – that is, comfort and efficiency all without pedal feedback, bob or brake-induced suspension stiffening – and all without the need for lockouts or other suspension inhibitors.

The Full Floating Suspension is not just more travel – it is BETTER travel!

How does it work?

Full_floater_dualtuned The Full Floater allows the engineers and designers more control over the rates and tuning of the suspension than ever before. Because there are two moving mounts that can be controlled, the engineers can adjust the instantaneous ratios of the suspension system throughout its full travel range to do precisely what they want – keeping the suspension active over the small stuff, but with good control of the mid stroke, and precise end-stroke compression.

Want more info? The first graph shows the difference in the instantaneous leverage ratios of the 2007 Fuel EX (red curve) compared to the new 2008 Fuel EX (blue curve).

Fullfloatershockleveragegraph

What you see is the 2008 red curve offers a “flatter” rising rate with a slight “hook” (digression) at the end of its stroke. This allows the system to have supple and active suspension over small bumps while maintaining a controlled mid stroke feel. However, due to the flatter pitch of the curve, the mid stroke offers a very fluid, smooth and controlling effect that does not have that firming feel (too progressive) and allows for better use of the available travel without rear suspension “wallow”.  The slight hook at the end adds a digression (falling rate) to the system which allows the suspension to continue to compress after most of the energy has already been absorbed and dissipated, as well as to counter the progressive nature of the air spring found on the shock. This gives the sensation that the bike has more travel than it really does, offering a bottomless feel and a higher quality travel (better use of the travel instead of just adding lower quality travel).

Competitor Comparison

So how does this compare with the competition’s systems? The following graph shows the 2008 Fuel EX compared with some of the most notable suspension designs used by its competitors:

Ffshockleveragecomparegraph1 The Ibis Mojo with DW-Link and VPP bikes fall victim to their very small links – they simply cannot provide the control needed due to the dramatic swing amount and radius it covers during use. But they differ slightly in effect as follows:

Mojo with DW-Link – This curve has a pretty steep progressive rate initially that flattens out in mid stroke and quickly goes to a digressive rate for the last half of its travel. This curve makes it almost impossible to optimize the tuning of the shock as the first part of the curve requires that the shock have light spring force and damping but the second part of the stroke requires the opposite. If you set this system up to have decent small bump performance, it will blow through its travel, giving the bike a wallow feel and will bottom out easily. It is almost impossible to optimize the shock tuning to this curve due to its contradicting requirements and huge swing.

VPP – This curve has a steep, digressive rate for the first 1/3 of its travel and then goes to a steep progressive rate for the last 2/3 of its travel. Due to the nature of the design and the rear wheel path this system has, the digressive rate at the beginning of the stroke helps to mask the inherent lack of small bump performance this design has. It allows for a lot of suspension movement for a smaller bump. But that also creates a wallow effect. The steep progressive rate after mid stroke creates a very firm shock effect and does not complement an air spring curve (too much progression effect when combined). As with the Mojo with DW Link, it’s very difficult to tune a shock to this curve. On both the VPP and Mojo with DW-Link, these curves become more of an issue as travel is increased (meaning that it’s easier to get a 4” bike to function than a longer travel application). Keep in mind that the original multi-link designs, that these bikes are based on, were conceived when downhill bikes were using under 6” of travel!

The FSR bike, while it does have a pretty good curve, the overall ratio is much higher than the EX. This means that it will require higher shocks pressures, creating more stiction and producing higher forces on the system, and requires heavier compression damping effect to control rider input (chassis stability). This is why Specialized bikes require some platform, inertia or lockout feature for efficiency and pedaling. The higher initial pressure needed also means the spring curve of the air shock itself will ramp up much more, which combined with progressive rate of the system, gives it a firmer overall feel and does not offer as fluid of a suspension feel or use.

All the while, the R1i design allows the weight of the frame to be kept and low and centered, with easy rider access to all shock adjusters and air valves.
By centralizing the weight over the BB (referred to as Mass Centralization-as important as Center of Gravity), the Center of Gravity is brought to the middle of the bike, under the rider, where the rider feels it much less when throwing the bike around (in line with his own weight and point of moment). Although lowering the weight helps, just lowering weight doesn’t do as much.

By keeping the shock low and centered, we’re also able to keep it in front of the seat tube. This keeps the shock and all its seals and bushings well protected from mud, rocks and other debris that gets thrown off the rear tire. And giving the rider easy access to the adjustment knobs and air valves – well, that’s pretty self-explanatory.

This design further allows room for a water bottle, and a full seat tube, allowing the rider a large range of seat height adjustment depending on the terrain and rider preference. Seat tube adjustment and protection of the shock are major benefits over other designs that don’t provide for this.

Well, that certainly is a lot of information. Everyone still with us? Good. How 'bout a ride?

Hey, you in the back! Wake up! It's time to ride now!

This post was modified on 8/22/07.  References to  “DW Link” have been changed to “Mojo with DW Link.”

Comments

Bob

You just have gotta love opinionated sarcastic jackasses like Paul. As a vintage motocross racer who races a 82 Suzuki RM125 aka full floater suspension the trek suspension has my attention. My question isn't if it works but if the aluminum frames on the EX8 and up are manufactured in America like the carbon fiber frames.

scott

Gavin, is this what we've come to see lately in more recent months? Do you have a few examples of some bikes that are showing off this type of system?

mike rydel

Suzuki revolutionalized their "Full Floater" rear suspension back in the late 80's and it was the best in its era. glad to see somebody has brought it back.

Mike

I don't know a whole lot about the engineering mumbo jumbo, but let me lay it down for you like this.
I'm 6'-0" 210 lbs. I ride a Fuel EX-8 running 140 in the rear shock and 110 in the fork. This suspension design eats up the small chatter bumps like they aren't even there but also smoothes out logs enough that I don't even have to get out of the seat when going over a 4" obstacle at 12 mph. As for Drops, I've hucked this sucker off of 4' drops onto a flat landing and while I've slid the O ring right to the edge of falling off, I have yet to feel anything remotely close to bottoming out. All of this with the same setup. Works for me.

Ryan

Paul is probably mad that he spent $2500 on a Mojo frame and, on race day, was beaten by a TREK Fuel EX. Probably the same kind of guy that hits the tennis ball over the fence and starts blaming his racket. ---

Anyway, I demo-rode a Fuel EX 8 and I was very impressed with the bike. I felt faster on the uphills and downhills, even though the bike weighs more than my HT. Every little root and rock was absorbed by the suspension so I never lost my momentum. Usually I'm constantly focused on riding around the obstacles on the climb so I don't lose speed.

Keep up the good work TREK.

Brian Stearns

Did you guys have to apply for a patent on this technology or was it already existing?

Reply:
ABP is a new technology was developed here by Trek, and we have applied for patents on this.

Paul

Wow, Trek actually has this on their site? This is disappointing. The misrepresentation here, particularly with the "setup woes" for the Mojo are startling. Sorry Trek, you just lost serious respect points.

Marketing misinformation be damned. To me, having to lie (or, stretch the truth even) signals the slow death of Trek is approaching.

“Paul,

I have to tell you, it’s hard to digest your comments. There is no misrepresentation of information in the facts we publish here. It’s pure analytical commentary.
If you have criticism on our comments, please point them out. Blanket disagreements do nothing to move the conversation forward.

– the Trek MTB team"

Michael K

I just read the article. I can't say I am buying the "engineering" behind the hype. First off, the graph which shows the comparison between 07 and 08, where the first bullet states better small bump compliance while the graph shows lower initial leverage ratio is a clear mistake. Lower leverage ration means the suspension is harder to compress, so no, it is not more supple for small bumps. Your comments on DW-Link are also incorrect. Since the air spring has a progressive rate curve with very little progression in the mid stroke (curve nearly flat), it is wise to reduce compression ratio, which reduces the wallow, whereas at the end of stroke, it is again wise to increase the leverage ratio to fight the highly progressive behavior of the air spring and be able to achieve full travel. These are just a couple of comments I have.

Seems like the Full Floater would be best used with a coil sprung shock. A high volume sleeve air shock may work OK as well.

rick

The Trek spiel is incomplete and has some really bad mistakes as well. Spring curve changes with starting pressure?! Wrong. The shape of the curve is the same starting with 10 psi or 10000. Not debatable, just wrong.
They don't include the shock spring curve and the force at the rear wheel vs travel. You'd see a graph of what the rider feels. It's a level or two deeper in the calculations. Maybe next year. Then the following year, they can start on anti squat. After that they can ask Dave for a license once they understand what's going on!

H

Gavin D

The obvious question is will we see a similar system appearing on other Trek bikes such as the sessions?

Answer: Keep you eyes peeled! There's info floating around on at least 1 more bike featuring these technologies....

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