[OGRipper]

Also, air/spring hybrid? so we loose the weight savings of air, while simultaneously lose the ability to really dial and perfect the springweight of a regular spring?

I agree it's heavier than a pure air fork, but you lost me with the second part.
You think having to choose between 2 or 3 pre-determined spring weights is better than a hybrid set-up where you get the benefits of a coil plus the ability to fine tune it for your weight or conditions?

 

[Owennn]

12 x 157 rear hub spacing. Just what is needed, another hub standard.

 

[HAB]

Not really.

Not unless they dropped their BB heights about two inches, which I doubt they did.

This.


Every single bike I own, DH included, is below 13". Do I hit pedals sometimes? Sure. Is it a worthwhile tradeoff for me? Hell yes.


On the "never ridden a bike that's too low thing" if we ever cross paths have a lap on my Draco. 7.5" travel, 12.9" BB.

 

[mattmatt86]

12 x 157 rear hub spacing. Just what is needed, another hub standard.

lolz. I was waiting for this to come up.

 

[Commencal-guy]

All the numbers look good for my preference except for the BB Height. 14" seems a bit on the higher end of the scale these days. Especially now that 13.7" is now considered the Norm for average Downhill bikes.



But hey at least they are getting there

 

[HAB]

lolz. I was waiting for this to come up.

Isn't the 12x142 standard just a normal 12x135 hub with an extra 3.5mm stuck on either side so there's a lip to catch on the frame, to make it easier to line things up? Sounds like you should be able to add a spacer to either side to take up the extra space, though lining everything up might suck. I assume the 157mm standard is the same kind of thing but for 150mm hubs?

 

['size]

Isn't the 12x142 standard just a normal 12x135 hub with an extra 3.5mm stuck on either side so there's a lip to catch on the frame, to make it easier to line things up? Sounds like you should be able to add a spacer to either side to take up the extra space, though lining everything up might suck. I assume the 157mm standard is the same kind of thing but for 150mm hubs?

there are spacers included with the frame/bike to run a standard 150.

"The rear end also features 12 x 157 millimeter spacing, referred to by Trek as 'ABP DH Convert'. Now, before everyone gets up in arms about another new axle standard, it needs to be said that the system is easily converted to fit standard 150mm hubs simply by swapping out the hardware with some included parts. Trek's wider, 157 millimeter axle spacing nests into a small shoulder which automatically aligns the through axle with the dropouts and hub. (Same as the 142/12mm hub design). The system lets you easily center and install the rear wheel without struggling to align the axle with the hub. Easier is better, right? If you want to use standard-spaced, 150-millimeter rear wheels, just install the standard dropouts and you're set."

 

[HAB]

there are spacers included with the frame/bike to run a standard 150

Yeah, I didn't read the article, I was just thinking something along those lines aught to work.

 

[RedOne]

the "hybrid air fork" on the 40 does seem interesting. im surprised we havent seen anymore info elsewhere

The question is will it be Marzocchi Air Assist or Manitou MARS hybrid style.

 

[dropmachine]

I have a question.

Just how stupid are the people that are so inept that they can't seem to line up a rear axle thus requiring a new muppet standard, and why are they allowed to touch their own bikes anyways?

 

[IH8Rice]

I have a question.

Just how stupid are the people that are so inept that they can't seem to line up a rear axle thus requiring a new muppet standard, and why are they allowed to touch their own bikes anyways?

they dream of F1 style pit stops. every second counts.

 

[Tmeyer]

I have a question.

Just how stupid are the people that are so inept that they can't seem to line up a rear axle thus requiring a new muppet standard, and why are they allowed to touch their own bikes anyways?

Been thinkin the same thing since the 12x142 was released.....

 

[Transcend]

the "hybrid air fork" on the 40 does seem interesting. im surprised we havent seen anymore info elsewhere

Only a very few people knew that there was anything special going on in his fork. Even last week at Windham, no one from Fox would tell me who else was even on that fork, besides Gwin. There's obviously a few guesses that would be fairly accurate, but no one was talking. I found it odd that they'd tell me about what was going on inside the fork in Whistler a few weeks ago, but wouldn't tell me who was on it!

 

[Transcend]

i just "hybrid air"'d my 888. its money. add 1 psi or subtract 2 psi depending on needs (lots of berms vs. fast, rough and straight). why in the world would anyone want mechanical preload anyhow? it does not change the spring rate, only the sag.

Not the same system at all. The fox is half air spring, half coil spring. Coil spring bottoms out, then air spring kicks in, allowing you to control the ramp up with extreme precision.

 

[IH8Rice]

Even last week at Windham, no one from Fox would tell me who else was even on that fork, besides Gwin. There's obviously a few guesses that would be fairly accurate, but no one was talking.

did you get any shots of Gee's bike/fork from last weekend? or is it really just a Trek only product?

Coil spring bottoms out, then air spring kicks in, allowing you to control the ramp up with extreme precision.

its a bottom out control? the audio on PB makes it seem like just a preload adjustment like the old Marz forks

 

[Inclag]

Not the same system at all. The fox is half air spring, half coil spring. Coil spring bottoms out, then air spring kicks in, allowing you to control the ramp up with extreme precision.

So the air spring has no effect on initial spring rate, preload, etc??

 

[Transcend]

did you get any shots of Gee's bike/fork from last weekend? or is it really just a Trek only product?


its a bottom out control? the audio on PB makes it seem like just a preload adjustment like the old Marz forks

It's more than a bottom out, but from what I was told it does that fairly efficiently. It's a hybrid spring basically. So you basically have a 2 stage spring, and the second half can be very precisely controlled.

Inclag: That is exactly what I was lead to believe by the person who explained it to me in pretty decent detail. The coil spring controls the top part of the travel, the air spring the bottom.

 

[alpine slug]

Been thinkin the same thing since the 12x142 was released.....

yeah I mean it's not like my bolt-on Hadley achieves the same thing in the "old" standard... I need the "new" standard because... well... because it's new!

 

[kidwoo]

Not the same system at all. The fox is half air spring, half coil spring. Coil spring bottoms out, then air spring kicks in, allowing you to control the ramp up with extreme precision.

After what 8 years or so of making a fork that's so linear it requires heavy HS damping which until very recently didn't even work on the things, they finally directly do something with a spring system.

Hallelujah!!!

I bet that's going to be a damn good system. I still wonder why they're so bullheaded about just making a dh air fork.

 

[p-spec]

make the spring the right flipping size to make it stfu on the mountain.

but that makes to much sense

 

[General Lee]

I have a question.

Just how stupid are the people that are so inept that they can't seem to line up a rear axle thus requiring a new muppet standard, and why are they allowed to touch their own bikes anyways?

Seems kinda' dumb since your average RM'er is just going to install it once as tight as possible, never remove or grease it the entire season, cover it with mud, shoot it with the hose, and then complain that it's a POS because it's seized and they can't get it out in November.

 

[RedOne]

Not the same system at all. The fox is half air spring, half coil spring. Coil spring bottoms out, then air spring kicks in, allowing you to control the ramp up with extreme precision.

That is exactly how the Manitou MARS system would be described.
Have that in my 145mm Nixon.

MARS Air

MARS Air is a hybrid spring consisting of a small coil spring and an air chamber. The two springs work in series, minimizing sticktion and providing smooth, bottomless travel. The result is a fork with the suppleness of a coil spring and the light weight and adjustability of an air spring.

http://www.manitoumtb.com/index.php?page=tech

 

[GoodbyePorkPie]

Seems kinda' dumb since your average RM'er is just going to install it once as tight as possible, never remove or grease it the entire season, cover it with mud, shoot it with the hose, and then complain that it's a POS because it's seized and they can't get it out in November.

You make too much sense this should go into the tech section, but probably get banned instead.

Regardless of the static numbers of the 9.9 and the 12x157, Trek seem like they are at least providing the options to keep everyone happy unlike some other manafacutures where having to go source or make stuff to fit/function.

I like it and the Slash.

 

[Commencal-guy]

The Hybrid Air system is def not a totally new system. Its just a more refined version of an Air assist. I remember back Mickey had a post about using the Boxxer Air cap and using that with an extra soft Boxxer spring to help dial the fork's spring weight.


I think the Hybrid Air Fox is more interesting than the Trek Carbon.

 

[Steve M]

I still wonder why they're so bullheaded about just making a dh air fork.

Because plain air spring curves just aren't that good on a DH bike. The crappy falling rate at the start of the travel means harshness and lack of support in the midstroke, the only saving grace they actually have for DH applications is the progression. This system sounds better, but it's basically a more refined/easily adjustable equivalent to doing up the footbolts in a Boxxer Team (R2C2 as they're now calling it) in different positions. I think it's promising, but whether it works well really depends on how refined it is.

 

[- seb]

How is an air fork falling rate at the start? Surely it ramps up from the very beginning?

 

[Steve M]

How is an air fork falling rate at the start? Surely it ramps up from the very beginning?

That would only be true if there was no negative chamber

You're a spreadsheet guru, run the maths.

 

[- seb]

That would only be true if there was no negative chamber

You're a spreadsheet guru, run the maths.

Ah ok. I've never run an air fork, or paid much attention to them! In my head though I still don't think a negative chamber would make a fork FALLING rate. It'll make it soft at the start, sure, but it still be progressive from the very start, no?

Surely as soon s you move 1mm into the travel, the pressure in the pos chamber increases, the pressure in the neg chamber decreases, and the force required to move it a further mm will be harder than the first mm?

Or am I being stupid? I expect I am - educate me please

 

[Steve M]

Ah ok. I've never run an air fork, or paid much attention to them! In my head though I still don't think a negative chamber would make a fork FALLING rate. It'll make it soft at the start, sure, but it still be progressive from the very start, no?

Surely as soon s you move 1mm into the travel, the pressure in the pos chamber increases, the pressure in the neg chamber decreases, and the force required to move it a further mm will be harder than the first mm?

Or am I being stupid? I expect I am - educate me please

The negative chamber is always of a lower initial volume than the positive chamber, which means that for a given rate of shaft displacement, the pressure in the negative chamber drops faster than the pressure in the positive chamber increases. Initially this means you effectively have a very stiff spring rate... however because the rate of pressure drop in the negative chamber is constantly decreasing (ie pressure in neg chamber stays closer to constant), the spring rate actually gets softer as you go further into the travel, up until such time as the proportional change in volume of the positive chamber becomes significant enough to push the spring rate back up again.

As a result, you get a falling to linear to rising rate in the spring. There are ways to tune around this (having an enormous negative chamber for example, but then the negative pressure is significant the whole way through the travel, and you need higher pressures overall), but this is the general shape of the rate that you end up with using a standard positive/negative air spring setup (ie everything currently on the market except TALAS as far as I am aware - and possibly some of Marz's offerings that I haven't investigated yet). Basically what this means is a spring that's significantly preloaded and stiff initially (bad for bump absorption but good for ride height and pedalling), soft in the middle (good for bump absorption but bad for ride height and stability, requires a lot of damping support) and ramps up at the end (generally good in all respects).

However, this kind of rate (at least in rear shocks) happens to mesh very well with certain bikes that have complementary (ie matching but opposite) leverage rate curves, in other words, progressive to linear/digressive, to help iron out the digressive to progressive air spring into something with better bump sensitivity AND better stability. The two bikes out there that most prominently feature this are the Banshee Legend and the IH Sunday.

Unfortunately, most popular forks don't have rate modifying linkages, so that can't really be achieved without clever positive/negative spring tuning in a fork. Strangely or not, my most preferred air sprung fork is actually the Fox Floats with the dual-rate coil negative spring. Other forks (such as my current RS Revelation) with independently adjustable pos/neg chambers can be set up to at the very least get rid of the initial preload feeling too, but self-adjusting systems like Solo Air don't have that possibility.

On topic - I think this new hybrid system from Fox has a lot of potential for eliminating the excessive linearity of just a coil, as well as the shortcomings of the typical air springs. I suspect it will need to be tuned quite finely though.

 

[kidwoo]

Because plain air spring curves just aren't that good on a DH bike. The crappy falling rate at the start of the travel means harshness and lack of support in the midstroke, the only saving grace they actually have for DH applications is the progression. This system sounds better, but it's basically a more refined/easily adjustable equivalent to doing up the footbolts in a Boxxer Team (R2C2 as they're now calling it) in different positions. I think it's promising, but whether it works well really depends on how refined it is.

I don't really agree that dh forks as a whole need to exhibit what you're describing. I've had one that does but there are many ways to go about it. Although we may be thinking the same things with your 'plain' air spring mention.

Fox coil forks have always sucked until they finally got their compression damping to work anyway. 4 years ago, an air fork would have been even more justifiable. Now it does work. And it works pretty well. I think coupling that with a proper volume air spring would be great.

I don't disagree that this system sounds really promising. I just continue to be entertained by the company that made the first really good air forks absolutely refusing to make a DC one. The 36 180mm forks are really good, and the 40mm stanchion totems that RS is making are really good, so I doubt 20 more mm is out of reach for fox....at all.

 

[- seb]

So a "negative" spring isn't one that simply pushes "against" the normal air spring? Not saying you're wrong, just that I'm very ignorant about these things. Can you show me a decent diagram of the set up?

 

[P.T.W]

Seb think of like.
A negative spring basically works the same as the main spring but kinda backwards. As you know a airspring "ramps up" as you compress it. A when your fork is at full extension the negative spring is fully compressed (ie at the harder end of its stroke) and as your fork compresses the negative spring extends to its fully open position ( the softer end) hence the falling rate. And as Socket stated, the negative spring has a smaller volume so this rate change happens much more abruptly. And the fork will be falling rate (under compression) until the positive and negative spring pressures are equal, then it will start to ramp up.
Hope this made sense, I'm sure Socket can explain it better

 

[heavy metal]

It's more than a bottom out, but from what I was told it does that fairly efficiently. It's a hybrid spring basically. So you basically have a 2 stage spring, and the second half can be very precisely controlled.

Inclag: That is exactly what I was lead to believe by the person who explained it to me in pretty decent detail. The coil spring controls the top part of the travel, the air spring the bottom.

So its kind of like what happens when you raise the oil levels in an open-bath fork but with its own independently designed circuit?

Pneumatic bottom out?

 

[Steve M]

I don't really agree that dh forks as a whole need to exhibit what you're describing. I've had one that does but there are many ways to go about it. Although we may be thinking the same things with your 'plain' air spring mention.

Fox coil forks have always sucked until they finally got their compression damping to work anyway. 4 years ago, an air fork would have been even more justifiable. Now it does work. And it works pretty well. I think coupling that with a proper volume air spring would be great.

I don't disagree that this system sounds really promising. I just continue to be entertained by the company that made the first really good air forks absolutely refusing to make a DC one. The 36 180mm forks are really good, and the 40mm stanchion totems that RS is making are really good, so I doubt 20 more mm is out of reach for fox....at all.

Agreed on most counts there. My experiences with the different type of spring/damper combinations could be summed up as this:

Coil spring only, no air ramp up (40s):
- Allows good control of the early and mid-stroke if you can get sufficient compression damping, but requires either fairly heavy compression or hydraulic bottom out circuitry to keep the thing from bottoming harshly from time to time.

Air spring only, no negative coil assist (Solo Air forks):
- As discussed above, tends to be harsh off the top, blow through the midstroke, but ramp up well at the end. Some riders like this because the bump absorption in the middle can be pretty decent for just running over stuff at moderate speeds, but I find that the faster the rider, the less suitable the spring is, because you end up cranking the compression to get some kind of mid-stroke support, which then means the end stroke spring ramp up is excessive.

Air spring with negative coil assist (Float forks):
- Works well in almost all regards because the negative spring rate is constant rather than digressive, which reduces the falling rate effect and means you don't get that sticky/overly preloaded feeling, but only for a certain range of pressures, because essentially the negative spring rate isn't changing proportionally to the positive spring rate.

Air spring with adjustable negative chamber (Dual Air):
- Can eliminate the excessive preload feeling but still has the same issue that the negative chamber volume expands rapidly and you get the falling rate mid-stroke effect. Works alright for XC but still could be better for DH IMO.

Coil spring with air bottom out assist (Marz, Boxxer Teams, new 40s by the sounds of it):
- Arguably the best in every respect because you can independently adjust early, mid and end stroke interactions. You can take it too far, such as by having either no air-assist to control bottom out meaning your coil spring rate has to be too stiff or your compression damping very heavy, or by going to the opposite extreme and having an air assist that's way too strong to compensate for a spring rate that's far too soft early in the travel (eg the first gen 888 recommended setups). I'm guessing the new 40s have changed the game up a bit by allowing pressure changes to the secondary air spring rather than just volume changes, though that is purely speculation based on how some people are talking and could be completely wrong!

 

[kidwoo]

Yeah we're mostly on the same page.

Don't know if you've ever setup a fox air fork with higher pressures but topping out that negative coil spring is annoying as hell. Plus it gives you more travel and screws with AC dimensions.

Certainly don't agree with the solo air bit though. I'm on my second one now, a totem and now boxxer and I think they rule, better than their coil counterparts and stay at their designed travel regardless of air pressure. I don't exactly putz around on the things either. The boxxer is pretty new so that may change but I didn't have any real complaints at all with the totem.

 

[Commencal-guy]

I agree 100% with what Socket stated above. It's a real bummer that the Solo Air design has such a limited tuning capabilities. For me its the best overall (Ideally) but in practice, not so great. However its good to see Rock Shox trying to toy with the design. Example the 2010 Boxxer World Cup Solo Air spring assembly is a POS. It was harsh in the initial stroke and blew through the mid stroke like crazy. I had to run a lot of compression/ and sacrifice more comfort by adding more air pressure to compensate. Plus the Bottom Out adjustment didn't do much since it had such a wide range and the fact that the 2010 Spring assembly had a floating negative air spring.


The good side of things is that the 2011 Solo Air spring is such a big improvement. It isn't as harsh compared to the 2010 in the beginning stroke, It has exceptionally well defined mid stroke support, and the end stroke retains the nice progressive rate. The 2011 Solo Air spring doesn't have the floating negative air spring which allows the better air displacement. Also the Bottom Out adjuster has a better more noticeable range of adjustment.

Hopefully Rock Shox can go further with the Solo Air design and tune it even better. Its a well thought out design since the Air spring will always equalize even with gradual psi increase due to heat. And there is less things to go wrong because of the simplicity.



Socket do you happen to know the X Fusion Vengence Air spring design? It'll be interesting to see what they did to tune theirs. I really like the dynamic stroke in the air spring.

 

[kidwoo]

Maybe that's the difference. I just got a 2011 boxxer and have never even ridden the 2010s.....

Still though....maybe that proves it can be done well?

 

[Steve M]

Maybe that's the difference. I just got a 2011 boxxer and have never even ridden the 2010s.....

Still though....maybe that proves it can be done well?

Would I be right in guessing you're pretty light, like 70kg (150lbs ish) or less? Because for very light riders, the solo air stuff can work pretty well due to the fact that the air volume ramp up in the lowers has a bigger contribution and you end up running less pressure proportional to your weight (meaning less initial harshness) than a heavier rider. Personally I've tried air and coil in the same Boxxer and preferred the feel of the coil by far.

It's also entirely possible for riders to simply get used to setups that other people find whack. A mate of mine at 6'2" was riding a medium 951 that just blew through the travel like crazy due to his setup, but he loved it because he'd spent two years getting used to it. After a couple of days on another much more linear bike, he was blown away by how much more feel he had through the pedals when the rear end wasn't disappearing from underneath him, and he wasn't hanging off the back of the bike like an ape due to it being 2 inches too short for him. Up until he spent enough time on something different to get used to it, he loved what he had. Not saying this is necessarily the case with your experiences, but it can happen.

 

[kidwoo]

Hah....close. 160lbs. I can see what you're saying about top end BS at higher pressures. That's every air fork that gets weird. I had to put a different topout spring in one of my dirtjumper forks because I set it at 4" and it extended to 5. So yeah that's a good point.


It's not from riding a whack setup man I can promise you that. I know what I'm doing and go back and forth between bikes I spend a lot of time setting up my bikes (especially now that suspension comes with compression damping that works like it's supposed to)...and sell things quickly that don't work. I also switched over from a coil boxxer I've been riding for two seasons.

FWIW, I'm sitting at about 48-49 psi on the air spring, about a quarter turn in on the chamber/bottom out and about 5-6 clicks in on low speed compression damping, zero HS damping.

 

[Steve M]

Hah....close. 160lbs. I can see what you're saying about top end BS at higher pressures. That's every air fork that gets weird. I had to put a different topout spring in one of my dirtjumper forks because I set it at 4" and it extended to 5. So yeah that's a good point.


It's not from riding a whack setup man I can promise you that. I know what I'm doing and go back and forth between bikes I spend a lot of time setting up my bikes (especially now that suspension comes with compression damping that works like it's supposed to)...and sell things quickly that don't work. I also switched over from a coil boxxer I've been riding for two seasons.

FWIW, I'm sitting at about 48-49 psi on the air spring, about a quarter turn in on the chamber/bottom out and about 5-6 clicks in on low speed compression damping, zero HS damping.

That's a reasonably stiff setting for the spring, that's proportionally about the same (or stiffer) than what I was running in mine, and that was set up pretty stiff. It's also possible that RS have enlarged the negative spring volume for 2011 to help smooth out the initial stroke... or that you ride really stupidly hard compared to me (entirely likely, I'm a pussy), and require insane bottom-out resistance and end up getting your mid-stroke support from the fact that your spring rate is proportionally stiffer anyway.