Mountain Biking - It's an upside-down world . . .

Seen at the US Open - - Gee testing a prototype inverted Fox:

http://lp1.pinkbike.org/p4pb6657322/p4pb6657322.jpg

Interesting to see the Big Gun finally going topsy-turvy. Makes me feel downright ahead of my time (made the switch back to inverted mid-last season).

More info here:

http://www.pinkbike.com/news/Fox-Prototype-Inverted-DH-fork-World-Exclusive.html

First, I hadn't noticed that in any pictures, then again I hit my head recently.

Second, is it more stable DHing or is it just a new marketing tool to open up the pocket books of the gimmick addicted weenies among us? It makes sense just looking at it. But can you demonstrate better times, handling a section than used to eat your lunch, is that possible.

^^I wouldn’t call it a marketing ploy - - although there are accusations of that out on the interwebs already - - i.e. - planned obsolescence, etc.

Inverted forks have been around the whole time but they got a bad rap from some early design quirks. A few did not run large enough uppers or stanchions and were a bit noodly. At the time they first came out, it was the only way to go long travel (7, 8 inches and beyond) because right-side-up forks would be too flexy. But the metallurgy got better, lowers castings got stiffer and the RSUs (right-side-ups) could get stretched out to the longer travel lengths.

The advantages to inverteds are their fore-to-aft stiffness: a lot of bushing overlap and the fact that fat upper structures are providing strength over a large percentage of the fork’s length rather than the more spindly stanchions. The minuses are: they are perceived to have less lateral rigidity and USDs (upside-downs) are, as a group, a bit heavier than their RSU counterparts.

I personally have liked my inverted forks better than my conventional dual-crowns - - they’ve always been more plush and (I think) tracked the terrain and were more forgiving on blown landings than my RSU forks. I attribute the plushness to the fact that there is more internal volume to work with in creating a damping cartridge but that might just be my unschooled ‘armchair-engineer’ evaluation.

Looks like it'd be aaaawfully wobbly to me... In my (highly qualified 20 year old) mind, the more connecting the stanchions, the better.
But i'd never need that much travel anyways, I like my propulsion to rely on me, not gravity, thankyouverymuch.

Looks like it'd be aaaawfully wobbly to me... In my (highly qualified 20 year old) mind, the more connecting the stanchions, the better.
But i'd never need that much travel anyways, I like my propulsion to rely on me, not gravity, thankyouverymuch.

While the inverted slider is still obviously very much in the prototype stage, they were confident enough in it to let Gee put in a practice run at the US Open for all to see - that speaks volumes.

Where can I get a set of calves like that? Or are they prototype too?

I perceive it to be stronger. The proximal end would have alot more stress on it b/c that's the point of connection with the HT, right? Therefore larger tubes would stabilize it better. I halfway feel that the reason people get so skeezed out by inverts is that they think they'll leak sooner. Now Fox needs to make a 36 Vanilla 160 single crown invert...caveat being the lack of arch.

Just an observation from my arm chair, it seems like a better idea that the movement happens as close as possible to the axle. I would think that it would reduce twist and failure.

INow Fox needs to make a 36 Vanilla 160 single crown invert...caveat being the lack of arch.Marzocchi went there once, with a single-crown Shiver:

http://blog-imgs-31.fc2.com/s/s/1/ss17n66/marzocchi_shiver_sc.jpg

I think it flamed out quickly because of irresolvable flex issues. Seems they designed it around 30mm stanchions though, so the results were predictable.



Just an observation from my arm chair, it seems like a better idea that the movement happens as close as possible to the axle. I would think that it would reduce twist and failure.From the PB article:


"The old argument of inverted forks having [more] torsional flex needs to be thrown out the window as it is far less relevant than most believe. Keeping in mind that the fork is well into its travel when being ridden, which stiffens the inverted chassis up greatly, the cliche test of pinching the front wheel between your legs and twisting really has no bearing in real world applications. It is also interesting to note that many forms of motorized sport actually build in a degree of lateral flex to allow the wheel to follow the smoothest line through a section - especially when leaned over in a corner - which allows it to track better in the rough."

Also of note: In the moto world, superbikes have all gone to inverted forks because of needing to offset not only fore-and-aft flex forces but the lateral forces of braking/cornering, especially as displacements (and thus weights) have increased.

Yeah...I remember the shiver and thought it was freakin' cool looking...but they need to do a 40mm stanchion with 30mm TA to tackle the idea probably.

Inverted forks have been around the whole time but they got a bad rap from some early design quirks. A few did not run large enough uppers or stanchions and were a bit noodly. At the time they first came out, it was the only way to go long travel (7, 8 inches and beyond) because right-side-up forks would be too flexy. But the metallurgy got better, lowers castings got stiffer and the RSUs (right-side-ups) could get stretched out to the longer travel lengths.

Especially under bigger riders. I never found a set I could ride comfortably... lateral looseness always ended up a concern of mine.

Of course that doesn't mean I wouldn't try them again, its been a few years. :)

^^ I will somehow get up there this year. Been a lot going on and the calendar has gotten mucked around but we shall see. Then you can try mine and see what you think of inverteds (well, and RSTs in general).

^^ I will somehow get up there this year. Been a lot going on and the calendar has gotten mucked around but we shall see. Then you can try mine and see what you think of inverteds (well, and RSTs in general).

Some bitter sweet news. My time in Whistler is almost done. Time for me to move to the shore. Job is taking off and I have actually been spending a lot of time in the states. Head office wants me based out of their main base.

I will still work for the hotels, so can help get ya room nights if you need em :).. luckily I can still come up here every couple of weeks :)

**** somebody buy me a plane ticket to a TGMBG approved DH park...! I wish to dabble in the gravity-fed side of the sport...

**** somebody buy me a plane ticket to a TGMBG approved DH park...! I wish to dabble in the gravity-fed side of the sport...

What is TGMBG?

Some bitter sweet news. My time in Whistler is almost done. Time for me to move to the shore...

Awww, poor guy...living in North Van is going to be so rough. And you're so far away from Whistler!

Awww, poor guy...living in North Van is going to be so rough. And you're so far away from Whistler!

Is that sarcasm?...hahaha (howdy buddy ;))

hence why the news was bitter sweet :p...