Fox Evols on Pro

[S.Diddy]

The reason you would want to lower ride height is to achieve the proper sag (on a mtn machine) on a snow cross or high performance trail sled there would be many more reasons to lower the ride height.

And yes you can increase sag on the sled and just boost the pressure in the EVOL chamber. What your left with is a sled that feels like it is riding on marshmallows until it bottoms out hard. As soon a you soften the spring rate enough, the rate of compression quickly exceeds the EVOL chambers ability to control the shock.

I will agree that you could lower the air pressure enough that pumping the Evol chamber up to max would not compensate for the low main chamber pressure but it is a non meaningful fact. There is nobody in this world that would need their pressure that low, and if they thought they did they would be off the deep end with what they consider proper shock set-up. I run my shocks with lower main pressure than anyone I know (I weigh 135lbs), and it's not even close to feeling "like riding on marshmallows".

 

[hyperduc]

I will agree that you could lower the air pressure enough that pumping the Evol chamber up to max would not compensate for the low main chamber pressure but it is a non meaningful fact. There is nobody in this world that would need their pressure that low, and if they thought they did they would be off the deep end with what they consider proper shock set-up. I run my shocks with lower main pressure than anyone I know (I weigh 135lbs), and it's not even close to feeling "like riding on marshmallows".

With the EVOL R's I had on my M8, ]10 psi was the difference between a shock with adequate spring rate and a shock that rode too low into the suspension travel.

Service life between rebuilds, durability, stiction, heat induced fade, consistent spring rates. The float doesn't beat a quality coil shock in any of these areas, weight savings are about it. I'm not sure why you're extolling the virtues of the fox floats handling abilities, when fox themselves will tell you that the ONLY advantage to a conventional set-up is weight loss.

 

[AndrettiDog]

Another side note. I've had two sleds with Evol R's. Yes you can carry your air pump and make adjustments on the fly but I found that was just for the setup. After I got them where I wanted I didn't adjust the air other than with the adjustment knobs. It's not like you will adjust air for a beat up trail and then pull your pump out and adjust for powder. That's the job of the on-the-fly knobs. Just saying, to me it's not much different than changing the Exit preload or springs.

Both shocks have their purposes and downfalls. I just think the best pure shock is the coil over X1. You want light weight, the Zbros guys will tell you that you want another shock. As I stated above, it's 5 lbs more over STOCK so probably around 3.5-4.0 lbs more than the Fox Evol R and even closer to the Evol X.

 

[gman086]

FWIW not all Evols are created equal. Mine were custom valved by Tom Dines (similar to what PUSH does to their (Fox's) mtn bike shocks). As I understand it, he has patents and Fox cannot send out theirs with his valving/high-flow piston system that they make to his specs. I can tell you they give up nothing to Z Bros shocks!

Have FUN!

G MAN

 

[S.Diddy]

With the EVOL R's I had on my M8, ]10 psi was the difference between a shock with adequate spring rate and a shock that rode too low into the suspension travel.

Service life between rebuilds, durability, stiction, heat induced fade, consistent spring rates. The float doesn't beat a quality coil shock in any of these areas, weight savings are about it. I'm not sure why you're extolling the virtues of the fox floats handling abilities, when fox themselves will tell you that the ONLY advantage to a conventional set-up is weight loss.

Stiction, heat induced fade? We ride in cold temps and don't encounter any problems with such things, and even so we never cycle long and hard enough to create an issue. Even the 4-wheeler applications fox makes in this set-up doesn't. There is too much volume to incur any noticeable difference. Consistent spring rates, well that would only be a result of heat, which again does not apply to the snowmobile app. Durability?? Well I can tell you that I have broken so many sets of coil-overs it's a joke. The Evols are the only shock I have never snapped the shafts in half.

As far as someone working for Fox telling you the only advantage to going with an Evol set-up is weight savings, well thats the first I've heard of it.

Well I guess there comes a time when you have to agree to disagree. I think we have very different views on shocks. I know I have made my points giving facts in previous posts and have tried to answer the original question...should he go with Evols on his new pro? I also took M8 Chris out riding last week and know that he was able to see how amazing the Evols perform.

 

[AndrettiDog]

You are right, agree to disagree. But it's a good conversation of what each shock does.

 

[KAWGRN]

I agree with Hyperduc the Ohlins are the answer I just wish I had the coin for TTx all around but till then I will use the EvolX as I wouldnt ride my race KTM with out adjustable rebound and High/low speed compression ,,, now the spring is another matter

 

[hyperduc]

I agree with Hyperduc the Ohlins are the answer I just wish I had the coin for TTx all around

Pretty much sums it up, if you can't afford or don't know the difference then just go with the floats. Still trying to figure out why stiction wouldn't apply because it's a cold weather environment or how a shock shaft with nearly 5 times the surface (and therefore seal contact) is going to perform better.

But whatever, he's happy with them and I guess thats all that matters.

 

[Dmill]

i feel like this thread went a different direction, i want to hear how these perform on the pro, what peoples settings are for weight and what type of riding they do... just purchased a set for summer upgrade and got a podium x for the rear instead of the air shock... would love some good starting numbers and advice seeing as i have a few months before i will get to test and tune.

 

[GoBigParts]

The Walker's on the Pro and the new rear skid are 90% better than the Walker air shocks and the older skid. The stock sled flat out rips and handles very well. However, there is probably another 10%-20% gain by going to the aftermarket shocks or custom valved shocks. I personally run the Evol X's but I have bad knees and find the air shocks help reduce fatigue, plus I run with out a sway bar, and have a setup that I fined tuned for myself.

I would think the Stock WE's can be custom valved to suite most needs. However, If you don't need to think about costs of anything why not go with the Exits?

The Fact is you can not get multiple spring rates with the stockers like you can with the exits or can you get position sensitive valving like the old fox PPS. However, how many of us need that kind of tuneability when we are riding mostly powder anyway? I would say get your stockers rebuilt after 500 miles and get them properly valved to suite your needs.

 

[mountainhorse]

Some notes on the EVOLS as I've learned them from the Factory (Jeff Favorite), Mark Holz and Tom Dines.

I know that there are many current EVOL owners out there that already know the info below..this is for those that haven't heard it before.

The EVOL refers to the Extra VOLume air chamber with a floating piston inside of the chamber.

The EVOL shocks will come in three different iterations this year.
1) The EVOL-X with full H/L compression settings (DSC), main and EVOL air chamber setting and rebound adjustment (5 different settings)
2) The EVOL-R model with Rebound setting, main and EVOL air chamber pressures. (3 different settings)
3) New for this season (already installed on the shock) Float-EVOL with main and EVOL chamber settings.

All three will have the advantage of the negative air spring which an older standard Float shock updated with the "EVOL kit" will not have.

IMO, the best upgrade on standard Float shocks (Pre Float-2) is the Float-2 upgrade.
The EVOL upgrade was designed with the Float-2 in mind and, if added to the Pre-Float-2 shocks, will not give the plushness that the Float 2 (without EVOL) has.

Rebound "clicker" also affects the compression valving as this is an adjustable bleed needle valve that allows some of the oil to bypass the piston (and it's valve stack). On the EVOL-R/X this rebound affects the low speed compression setting as well as the rebound... that "bypass flow" can move in both directions as the shocks cycles.


Ride Height: The ride height, if the EVOL chamber pressure is set correctly, is strictly a factor of air pressure in the MAIN chamber (AKA "air-sleeve"). You can not adjust the ride height with air-pressure and retain proper air-spring force for good ride character. On the PRO/IQ chassis... Ride height is a CRITICAL dimension for proper front/rear suspension interaction. If you lower the main chamber pressure to lower the ride height, you will change the character of the suspension action... Unless you have the EVOL chamber lower than main chamber then the EVOL pressure has ZERO affect on this initial ride height. If the EVOL chamber pressure is at the same pressure or lower than than the main chamber, the EVOL piston remains at the bottom of its stroke and does not move... negating most of the benefits of the EVOL chamber and it's floating pistons ability to provide a second spring rate in the bottom portion of the shocks stroke.

This is the primary reason to get a shock that is the correct length for the sled and not one that "kinda fits" plus correct valving for the sled and rider...a rebound/compression adjuster will not compensate if the basic valve stack setup is incorrect. Buying a set of used shocks from another brand/model is generally not a good idea unless you know that they are the same length and you can get them revalved for your application. An incorrect shock will certainly not perform as well as a standard base-RMK shock.

The EVOL chamber comes into play in the last 1/3rd (approx) of the shock stroke when the main chamber pressure ramps up. This feature allows you to run higher main chamber pressure for better control of the sled without the typical harshness in the last portion of the shock stroke. The EVOL chamber affects the spring rate when the air pressure in the primary chamber exceeds the air pressure in the EVOL chamber. Which is why the EVOL chamber is always set higher than the main air chamber.

Always adjust the air pressure with the shock fully extended (shock must be completely unloaded). Always adjust the air pressure in the EVOL chamber prior to adjusting main chamber pressure. Always check/adjust the main camber pressure after making EVOL chamber pressure adjustment.

Don't confuse the EVOL chamber with "Added volume " air chambers available in the aftermarket (the exception is the Hi-Gear Products "air control").. The EVOL chamber has a floating piston that separates the two air pressures (main & EVOL).

I have seen/helped many people in the field with amazing shock installations on their sleds that do not perform as well as a stock shock installation. If you don't know what you are doing and don't have the patience to "trial and error" setup and become familiar with the shock... IMO...get a shock with pre-set rebound and compression settings (like the Exit X0 or Float-2/Float EVOL (non "R" or "X"). If you know shocks and their function and how to tune them... get one that allows you to fine tune that shock. In the words of the Zollinger brothers (Ryan and Nate) as well as a Factory Fox tech... most people buy multi-adjustment shocks and end up with sub par performance because they have not learned how to adjust their shocks or don't take the time to do this on the snow....Those people would be better off with a LESS adjustable shock.

All this being said... I have ridden the Float-2 shocks, the EVOL-R shocks, the Float-EVOL and the EVOL X on the Pro-Ride and IQ chassis... IMO, for most riders the best choice in the Float shocks is the Float-2 with the Float-EVOL as the next higher priced choice for a bit more control in bottom harshness. The R and X models reserved for more experienced shock tuners and Extreme riders.

When evaluating what shock you want to buy...FIRST.. Be HONEST with YOURSELF... Are you truly an extreme rider/tuner? or looking for a more adjustable shock than the factory can afford to install on the sled and still sell it for a reasonable cost to the consumer??

BTW...IMO the WE coil spring shocks on the PRO's are top notch offerings that can be fine tuned / tailored for your weight and riding style at a very reasonable cost.

Can the aftermarket offerings give better performance in different or extreme conditions.. YES, especially if you represent the 10% of riders out there that can use that "difference". Are Snowcross racers, mogul bashers or hard core freeriders in need of a shock with more features.. again probably YES.

 

[gman086]

A tuning tip for Fox air shocks - wrap a zip tie around the shaft so you can see how much of the travel you're using. Shoot for Evol chamber pressures that just barely bottom on the biggest drops/hits you intend to take. Also rebound is critical but I've found the middle settings to be the best for most circumstances and a good starting point. Ride over a set of moguls and click 2 down or up (not just one as you probably won't notice the diff) and THEN adjust as needed.

Have FUN!

G MAN

 

[mountainhorse]

Here is a cutaway dwg of the EVOL X to give you an idea of the internal working components.

 

[mountainhorse]

Here are the pix of the Float-2 and Float-EVOL and Float-EVOL-R shocks.

 

[mountainhorse]

EVOL KIT

 

[Dmill]

what are typical pressures to start with, fox recommended 100 and 55, whats a good starting point for the pro

 

[gman086]

what are typical pressures to start with, fox recommended 100 and 55, whats a good starting point for the pro

Right where they recommended for the front shocks (and I've tried a LOT of different pressures). Will be somewhat dependent on rider weight and snow conditions too but that's a darn good starting point!

Have FUN!

G MAN

 

[gman086]

Would love to see a spring graph for the Float2 vs the Float Evol with some different Evol chamber pressures!

Cheers,

G

 

[mountainhorse]

I'll see what I can dig up.

 

[ruffryder]

Would love to see a spring graph for the Float2 vs the Float Evol with some different Evol chamber pressures!

Cheers,

G

Yah, that would be pretty interesting to see.

MH, maybe port some of this information over to the performance / modified forum as well. Might be pretty universal to all sleds...