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Prototype long-travel inverted suspension fork spotted from… Magura?

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prototype magura inverted suspension fork

Aboard a couple of Rotwild’s new X1 trail bike were prototype inverted suspension forks disguised in patterned duct tape. While their reps wouldn’t say anything about them, we took a close look and lots of pics to make an educated guess as to which brand might be testing it out.

The anodized knob colors, the shapes and fonts and some of the finer details suggest its a Magura, a notion reinforced by the Magura brakes mounted to them (the other bikes had Shimano brakes).

The first thing that jumps out about it is that it’s mated to a 140mm travel bike, putting it in a different category than the RS-1. That could mean instant competition for the X-Fusion Revel when it finally starts shipping (it’s still in development, and we saw the latest versions at their HQ in April, we’re just not allowed to talk about them yet).

prototype magura inverted suspension fork

Compared to other Magura forks (or most any brand, for that matter), the blue compression adjustment knob sits on the left. From the looks of it, it’s more of an on/off (open/locked) or multi position (open/firm/locked) rather than a 20-something click adjustment.

prototype magura inverted suspension fork

The pressed in steerer tube’s bottom is shaped just like the Magura forks we’ve tested.

prototype magura inverted suspension fork

The black seal caps on the bottom of the uppers also strongly resemble Magura’s design motif.

prototype magura inverted suspension fork

This one’s either being tested with only one brush guard, or the right side got ripped off.

prototype magura inverted suspension fork

The brush guard mounts with a small bolt on the outside rear. Note the bolt-in thru axle, just like Magura uses. And on the opposite side is a nice wide, stepped opening that should fit their integrated Torx tool quite nicely.

prototype magura inverted suspension fork

Rebound adjustment on the bottom left…

prototype magura inverted suspension fork

…and air valve on the right. Could be a 20mm thru axle, which would make sense for a long travel upside down (USD) fork, with additional bolts to clamp it down. It’ll be interesting to see if the axle can be threaded out without loosening the clamps, but all bolts are Torx and should at least work with the included tool that slots into the axle.

Magura made no mention of it at their press camp in Sedona this year, so we’re guessing fall tradeshows might be the earliest we’ll see something official.

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lluis
lluis
7 years ago

Only one brush guard as the other one got ripped off.

No further explanation on why inverted forks are a NO NO on mtb.

Tim
Tim
7 years ago

I’ll say the same things that I say every time an inverted MTB fork comes out:
1) The Cannondale Lefty is the only USD fork that is equal or superior to standard forks in terms of torsional rigidity
2) Nearly all inverted MTB forks use special techniques to regain part of the rigidity that they lose by using a braceless design: two crowns on a non-DH fork (Cannondale, Maverick); bigger thru-axle (Maverick- 24mm thru axle, Rock Shox RS-1, faux 27mm); crowns with collets instead of bolts, press-fits, or bonding (DVO Emerald- prototype only); one piece carbon crown-uppers (Rock Shox RS-1); key-in-lock axle-dropout interface (Manitou USD forks); integrated axle-lower legs (Cannondale); square legs instead of round ones (Cannondale); inner and outer legs that lock into each other with special channels in the fashion of dropper posts (can’t remember who); leg guards doubling as a very long brace (DVO Emerald)
3) Most of these stiffening techniques could be also be used, and indeed a couple occasionally have been used, on conventional forks to make them even stiffer
4) In spite of all the efforts to make up for the loss of stiffness that comes with eliminating the brake brace, most of the inverted forks (to my knowledge, correct me if I am wrong) are heavier and torsionally flexier than other forks in the same class.
Maybe this Magura fork will throw something new out there that will change the game and make their USD forks better than most others, let’s see.

craigsj
craigsj
7 years ago

“4) In spite of all the efforts to make up for the loss of stiffness that comes with eliminating the brake brace, most of the inverted forks (to my knowledge, correct me if I am wrong) are heavier and torsionally flexier than other forks in the same class.”

Tim, you seem to have forgotten your own point 1 which contradicts this.

You also seem to think that torsional stiffness is the only thing that matters and that using “special techniques” to improve it is somehow bad.

What matters is how well a fork works overall, not your biases on how a fork should be engineered.

Joe P
Joe P
7 years ago

As long as it doesn’t blow out the seals, doesn’t bind and can be pushed hard – I like em.

i
i
7 years ago

@tim,
some other facts:
1) every single company making forks for MTB has had a prototype USD fork.
2) most motrocross bikes use USD forks. Those that don’t still don’t have brake arches. They use 20mm axles, all this despite the fact that loads on them are orders of magnitudes higher than on any bicycle.
3) can you acknowledge that there is a chance, however slight, that the entire suspension industry might collectively know something about suspension that you don’t about fork design?

everything you said is true, what you didn’t say; namely that stiffer=unequivocally better, is probably not true. DVO talks about engineered flex at length in their blogs; I don’t know of anyone that’s spent time on a Emerald or current Dorado or even a Maveric DUC for that matter, that had anything bad to say about the stiffness. Every fork manufacturer could make a stiffer fork, ever wonder why they don’t?

'Merika
'Merika
7 years ago

@Tim

How long have you worked at Cannondale?

Tim
Tim
7 years ago

‘Merika- I’ve never worked there. I have a high opinion of the Lefty, but since you think I am a paid shill for Cannondale, allow me to bolster my credentials as a disinterested observer… I worked in a shop in the early 2000’s, and I recall Cannondale flatbar roadbikes coming with shifters that were incompatible with their front derailleurs, and I recall very, very bad brakes made and/ or spec’ed by them- both rim and disc. I remember building dozens of those bikes and feeling horrible about them getting sold. So no, I am not a Cannondale employee, and the only current product they offer that genuinely interests me is the Lefty. And even it has its flaws- the main one being narrowly-spaced hub flanges and can’t use Centerlock rotors. That said- the fact that the Lefty is around a pound lighter than the competition while being more torsionally rigid is agreed on by almost everyone.

Tim
Tim
7 years ago

@i-
1)”Every single company making forks for MTB has had a prototype USD fork”. OK, true. But Fox decided not to produce its (DH, dual crown) inverted fork. There was a prototype, and that was all. But yes, all other companies have even gone into production with their USD forks, although sometimes with limited runs.
2) As I understand it, MX bikes have weight floors, i.e., they can’t go below a certain minimum weight so the guy who has enough money to ride super-light, super-flickable, super-expensive and disposable bikes doesn’t have an advantage over other riders who can’t afford such machines. That means bike and fork makers can beef up lots of parts with chromoly steel construction. But- this is just my impression. I am not into MX, so my idea could be totally off; disabuse of my mistakes if need be.
3) I can definitely accept that suspension engineers and the bike industry might know more than me. You won’t find me designing forks. But- if we’re talking about collective decisions, then the industry definitely collectively decided a long time ago, around 1993, that telescopic single crown forks with a brace and the thin legs up top is the way to make forks. Just as a guess, more than 99% of suspension forks sold in the last decade have been non-USD. The number of USD forks being sold has always been small; each brand has one or maybe two USD forks out at a time, and these make up a very small portion of sales, aftermarket or OEM. That’s the collective decision of the industry. Also- while I accept that the industry might have a better idea of what to make and how to make it than I do, I also won’t discount my own taste and long experience riding bikes and observing the bike industry as a rider, shop worker, and yes, consumer. The bike industry is an industry like any other; overall, it gives us better and better stuff, but does make serious mistakes. It also gives us innovation only in a trickle, so we keep paying for incremental improvements. If I were in charge- I would do the same. What was a fad before- oval chainrings, press-fit bottoms brackets, internal cable routing- is absolutely reviled this decade, and then comes back as a fresh innovation the next. Big companies do sometimes make dumb stuff for bad reasons. Think those Shimano Dual Control brifters from around 2003.

Rigidity- yes, absolute rigidity is not a goal. It is my mistake for not saying that. Rigidity is partly a matter of taste- and weight, and riding style and conditions. Some people will be happy with the torsional rigidity of a USD fork with a 15mm thru axle, others like me won’t. Some couldn’t care less, and just want to ride. Still- while I haven’t crunched the numbers and looked at every fork on the market and its competitors, USD forks with a single crown end up being around a pound heavier than their non-USD competitors, are flexier in torsion to a degree that I personally dislike (I won’t invalidate others’ opinions for not caring as much about this, it is a matter of taste at the end of the day), and cost more because of small production runs.

Drew Diller
7 years ago

I want inverted forks so mounts can be put on the uppers, and front pannier / front water bottle mass is treated as sprung mass.

With conventional MTB forks this is not practical. Ever use a Salsa Enabler rigid fork? Imagine that kind of packing capacity, except your cargo in that area benefits from rather than hampers the suspension.

Extra weight be damned and extra complexity be solved. Bring on the inverts.

BillBob
7 years ago

The issue was kind of up right back in the beginning of Tim’s post. USD forks work for MX because MX bikes have power to spare, so weight isn’t so much of an issue. In the world of pedal bikes, where power is in short supply, people will pay 200% more for a part that weighs 45g less. In this supremely weight conscious world, USD forks just don’t make sense – and that’s why they’re so rare.

thesteve4761
thesteve4761
7 years ago

Nice rims.

Bud
Bud
7 years ago

I find myself strongly agreeing with Tim. Am I a bad person?

RoDe
RoDe
7 years ago

Mmmhhh interesting but 140mm is not enough I need a 160mm or 170mm fork.

Drew Diller
7 years ago

@Bud – I agree with his Lefty comments ,because I made the same judgements independently. (Plus I think the Lefty’s hub insert scheme is clever but WHY leave the disc rotor on the hub. OMG put the rotor on the chassis, and then the wheel on the rotor flange, like a car wheel. Could reduce number of bolts messed with per wheel removal from three to one.)

However, I am a bad person so I’m afraid I can’t answer your question.

Colin M
Colin M
7 years ago

@i

speaking as a long time Maverick DUC32 rider I can say that myself and other ex-Maverick sponsored riders pushed that fork to its limits and found it to be less stiff than modern 36mm forks. Great forks but at the race speeds we pushed those forks there is a point where it felt limp and noodly. That being said for trail use it is amazing and I’ll never part with the ones I still have. Zero stiction is a wonderful thing.

Chris
Chris
7 years ago

USD forks = bring out the haters! I’m just amazed at the pushback. If you’re so against them then don’t buy. Personally I am all for folks testing these in the name of progress.

Tim
Tim
7 years ago

@craigsj- I don’t have anything against “special techniques” to regain stiffness lost by not using a brace. Thank God those special techniques get used, these forks would be even noodlier without them. And it’s great when some of those techniques come to non-USD forks- I am thinking specifically of the Manitou Hex-Lock six-sided through axle; that is a great idea.I also like honking huge thru-axles like the Maverick 24mm- if 24mm Hex-Lock were the industry standard, I’d be on board.
I don’t see how my points 1 and 4 from my original post contradict each other; I said: “most inverted forks… are heavier and torsionally flexier than other forks in the same class” and “The Cannondale Lefty is the only USD fork that is equal or superior to standard forks in terms of torsional rigidity”. All USD forks except the Lefty are heavier and torsionally flexier than non-USD forks. Where’s the contradiction? Again, I don’t work for Cannondale, and never have. They simply pulled out all the stops, using three radical stiffness-increasing techniques: two crowns, square legs, and needle bearings instead of bushings. The result is the only lighter and stiffer than conventional telescopic USD fork.

Sorry if I have written a novel here, I do love a good debate, especially about bike gear! I don’t consider myself a hater, I just don’t see the rationale for this style of fork.

Pistolero
Pistolero
7 years ago

I think this type of work could work quite decentely, if designed decently;

– 30mm axle
– NO round tubes, make them square, ala cannondale, or make them oval. There was a brand with a prototype of inverted fork with oval legs, eliptical, or something like that, instead of round. I think it’s the brand that dt swiss purchased, pace, but i really really can’t remember now.

I think german-A forks or the springleaf one has some benefits, but the inverted fork is very complicated and expensive to really make them nice. Not like the pieace of shit the RS1 is.

Tim
Tim
7 years ago

M- I had a soft spot for the DUC32 just from the specs (under 4lbs, 6″ of travel- pretty impressive), and always wondered how a DUC36 would have been had it made it to market. Are you comparing it to modern single crown 36mm forks, or dual crown? How was it compared to forks of the day?
@Pistolero- I think yes, German A has oval legs. Halson Designs, who made inverted forks in the 1990’s, had an inverted fork with oval legs on the drawing board. Their designer also told me that, although an inverted design was their hallmark, they were planning on switching to a non-USD design once travel started to get longer (“longer” was around 4″). This was because, as he said, inverted designs, even ones with a through axle, got flexy at that point. Of course, there have been advances in materials and engineering since then, it’s just an anecdote.

Darryl
Darryl
7 years ago

Materials and processes along with economy of scale play a large part here.
I can remember when a major fork manufacturer categorically stated that 100mm travel forks could never be made with a single crown.

I still don’t think that having the sliding bits down in the crap will work long term, the sides of my forks have scratches all over them.

The single biggest improvements to today’s forks for me would be to make them last a whole bunch longer between services.
My car shocks go until the car is trashed, pulling the lowers on my mtb’s every 30h is just too short of an interval.

Miodrag
Miodrag
7 years ago

And what about of technology transfer from motocross bikes to mountain bikes? That is happening with brakes( 4 piston brakes) and why could not with forks( usd)? Usd fork with infinite travel+4 piston brake+carbon ceramic rotor( I hope soon)+lighter gearbox(future effigear, pinion p1)+christini awd+gates belt drive=??

Axa
Axa
6 years ago

Any news on this fork? Will the offer a version for non e-bikes.
Allot of interesting things going on around unconventional forks. Sad that the X-Fusion Revel seems to be a bluff, and that the Motion France did not succeed on funding https://www.kickstarter.com/projects/929331044/motion-france-dynamic-anti-dive-mtb-fork/updates
I will be the first one to sign up if the can make it alfordabe..

I would live to try one on my Tantrum

https://www.kickstarter.com/projects/812273700/tantrum-cycles-the-missing-link-in-full-suspension/comments

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