Specialized Granted Patent for Linkage Fork Design

Aug 16, 2021
by Seb Stott  

Specialized has been granted a patent titled "Simplified gas spring setup for a trailing link cycle wheel suspension," which relates to an air spring design for a linkage fork. The inventor is Dave Weagle - the same Dave Weagle behind dw-link suspension (among many other designs) as well as the Trust Shout and Message linkage forks which we've already reviewed. The design of the fork depicted in the patent is very similar to the two forks Trust developed before the company ceased operations in April 2020, citing a lack of cash brought on by the coronavirus pandemic. The main thing which makes this patent so interesting is that the applicant is Specialized Bicycle Components.

According to Weagle, when Trust closed their doors an intellectual property portfolio was put together and then sold in order to cover the company's liabilities. That means Specialized now has the patent on the design Weagle created, and can implement it however they'd like, or even put it on hold until the right opportunity comes up.

While Weagle's name is on the patent, he's not involved with Specialized's plans at all, and wasn't able to shed any light as to when (or if) this design might hit the market. Given all of the time and effort that went into creating the original Trust forks, he said, "I'm just happy it didn't get completely mothballed."

Trust Shout fork
Trust The Message trailing linkage fork.
The fork described in the patent looks a lot like the Shout and Message forks from Trust Performance.

Specialized have history of developing their own in-house suspension. Who could forget the 2007 Specialized Enduro with its Specialized-branded shock and 150mm-travel dual-crown fork? Not to mention their Brain inertia-valve technology used in their cross-country bikes. So perhaps "The Big S" is planning on developing an in-house linkage fork based off of Weagle's designs. The Trust Shout and Message both showed potential, but had their faults, not least of which was the hefty price tag. Perhaps with the capital, scale and expertise of Specialized, the full potential of the linkage fork will be unleashed at a more reasonable price point.
The Evolution of the Specialized Enduro
Could Specialized be working on innovative in-house forks? It wouldn't be the first time.

The fork has a damper and an air spring in one side and a (larger) air spring in the other.

As for the patent itself, the fork described shares a lot with both of Trust's forks. It's a trailing link design, meaning the axle sits behind the main body of the fork, and moves in an arc that curves back and then up as the fork compresses. This means that in the middle of the travel the fork offset is shorter than at the start of the travel, which results in greater steering stability (trail) when the fork is compressed. It's a four-bar linkage, which makes it possible to adjust the amount of anti-dive to help it resist compression under braking compared to a telescopic fork.

The fork has a damper in one leg, which sits below an air spring that operates in-line with the damper. A second air spring is housed in the opposite leg. The two springs mean the rider's weight is held up at both sides of the axle, which reduces the twisting force on the axle compared to a single spring. This is important given there's no arch to help keep the two dropouts from moving interdependently of one another, so if there was a spring in only one leg, the wheel would exert a twisting load on the fork chassis .

The shock absorber has a damper below an air spring using the same shaft to drive both the damper and spring piston
The piston area of the air spring in the non-damper side (B-B) is larger than the damper side (A-A), helping to balance the compression forces from the damper.

All the above is shared with the Trust Shout and Message, but the patent underlines that the springs in each leg are not identical. The unit containing a spring and damper is referred to as the shock absorber, and the spring in the other leg as the spring unit. The spring unit has a larger piston area than the shock spring. This is to increase the spring force on the spring-only side, compensating for the damper on the other side, which adds its own force depending on the compression speed. The idea is to make the forces more equal on both sides of the axle, at least at some compression speeds: "the first gas piston area (110) is less than the second gas piston area (111), which allows for a more equal force output between the shock absorber (44) and the spring unit (48 ), which helps to distribute forces more evenly in the linkage and avoid the detrimental results of angular wheel displacement."

Patent documents are written to keep the inventor's options open, but it sounds like the spring-only side will have around 25-30% more piston area, so providing that much more force for a given air pressure. "In some embodiments, the second gas piston area is between 2% and 300% larger than the first gas piston area ... In other embodiments, the second gas piston area is preferably between 15% and 100% larger ... and even more preferably between 25% and 30% larger than the first gas piston area."

Presumably, they could achieve this by increasing the pressure (by around 25-30%) in the spring-only side, but the patent focuses on ease of setup. The different piston areas balance the forces at the same pressure, so the user doesn't have to do any calculations. In fact, the patent suggests the piston areas could be fine-tuned so they offered the recommended spring stiffness when set to the same pressure (in psi) as the rider's weight (in lbs): "The disclosed simplified wheel suspension assemblies are designed to use a first gas piston area and second gas piston area that are sized so that when the suspension assembly is installed on a cycle, the gas pressure inside the shock gas spring 92 (for example when measured in PSI (pounds per square inch)) is equal to a recommended or predetermined pressure that produces an optimum ride for the user's body weight (for example when measured in LBS (pounds))". So for a 160lb rider, just inflate the springs to 160psi and go ride.

The patent goes on to claim that "The disclosed wheel suspension assemblies can be designed to be lighter in weight, lower in friction, more compliant, safer, and perform better than traditional wheel suspension assemblies ... [and] also reduce stiction and increase stability during braking, cornering, and shock absorption, when compared to traditional wheel suspension assemblies." These are similar to the claims made of Trust's forks, although the Message and Shout were a little heavier than their telescopic competitors at the time.

Finally, the patent suggests the fork may be particularly suited to e-bikes, so perhaps that's where the fork will end up, if we ever see it: "E-bikes are heavier and faster than typical mountain bikes. They are usually piloted by less skilled and less fit riders, and require a stronger front suspension to handle normal riding conditions... The beneficial caster effect described above with respect to the disclosed wheel suspension assemblies is an important improvement over traditional wheel suspension assemblies and reduces some of the drawbacks of E-bikes."



Disclaimer

I haven't read or heard anything about this other than the patent documents themselves, so I don't know anything about it other than what I can glean from the publicly available patents. I've reached out to Specialized for comment and clarification but so far haven't heard anything back.


208 Comments

  • 401 12
 Oh hello, did I hear someone say linkage fork?
  • 52 1
 *undertaker.gif*
  • 89 1
 Build it and they... Eerrr, Levy... Will come
  • 5 0
 @mikelevy ...if Specialized does do something with this..emphasis on the "IF"...do you think it has a better chance of catching on compared with previous efforts? thoughts on potential XC applications? Seems benefits come with handling under compression (more trail oriented).
  • 28 0
 @mikelevy actually read an article!
  • 4 5
 Patently giving a go to comment gold, pathetic
  • 5 0
 @SATN-XC: I'm gonna have to say no. Specialized has been successful with tires, but no one besides Specialized specs them OEM. This will probably be the same. It might make it onto some bikes as an aftermarket purchase, but might come stock on a bunch of specialized.
  • 29 0
 Dare I say that SHOCK looks like it’s from the FUTURE? They should call
it a…never mind.
  • 11 0
 @feldybikes: it’ll be thoroughly badged with FSR, though they’ll have to maybe distinguish front/rear.. FFSR, FSRR, RFSR, FSRF.. I that covers all combinations
  • 13 0
 If they don't call it the "Protour", I will be disappoint.
  • 6 0
 @SATN-XC: This is a brilliant move by S. They have the 'weight', $ and legal chops to protect it. It's not something yet, but it will be if done properly.
  • 6 0
 @Spencermon: This fork will be part of a Specialized Bike system……..could be a big success for them.
  • 4 0
 @SATN-XC: As long as it's better than the E-150 fork was. Spesh can probably put out enough bikes with them on to make it work, like Cannondale did with Lefties. The issue with past Spesh OE suspension was always reliability.
  • 3 1
 @rivercitycycles: I don't plan on buying a Specialized anytime soon so it'll probably never be something that ends up on my bike. Though I really did love riding the Message fork. If they follow through with it, it will probably drive quite a lot of sales on whatever bike they put it on. I still don't see widespread desire from riders that aren't already all-in with Specialized.
  • 8 0
 Stoked the Trust IP has a home. There was a lot of things that Trust Shout did well. Excited to see where they take it.
  • 22 2
 @SATN-XC: No, I don't think so, especially because it'd probably be a Specialized branded fork (or sub-brand, like Roval) and it doesn't seem like those are all that successful in the aftermarket world. Bontrager, Specialized, and other bike brands offer some impressive components, but not many people want them. Specialized's tires are great, and Bontrager has a bunch of killer tires as well, but it doesn't seem to matter. And which bike brand is going to spec a Specialized fork?

I liked a lot about the Message, but it also could feel pretty harsh over rough ground or high-frequency impacts, and we mountain bikers are used to the supple smoothness of traditional suspension. Specialized would need to improve on that, for sure, and maybe do a hell of a marketing job...? I'm interested!
  • 6 0
 as i was reading this i was thinking, i can already hear Levy on the podcast raving about how linkage forks are the S*** and they will kill e-bikes once and for all

"so efficient"
  • 2 0
 Got you attention!

So Mike, rumor has it you guys had a Motion E13 + in your grimy lil' paws ... what did you think of it?

Imagine the love child of a Motion fork and a Trust fork Smile
  • 2 0
 @nurseben: I did have one! But I was injured and out of action for too long and not able to put any time on it Frown
  • 2 0
 @DizzyNinja: You missed F'SHZZL
  • 2 0
 @Mfro: I think we all miss FoShizzle
  • 11 1
 C'mon, just bring back the Girvin already! Throw a sweet little EXT Storia on the front and should be good to go!
  • 3 0
 You're still a thing? I haven't heard from you in so long.
  • 5 1
 @DizzyNinja: fun fact, they already do that.

FSR stands for Future Shock-Rear, from back in the day when Specialized had their in-house Future Shock fork on some models. #themoreyouknow
  • 2 0
 @mikelevy: bummer, I’d be interested in your thoughts between the two:

I ride a Message and Shout fir a season plus, had a Motion E13+ for two months.

For big hits I liked the Shout best, for flowy smooth terrain I liked the Message best, but for all around I’d put my money in a Motion.

That Motion has a very cool damper, it’s harder as to turn by hand, and it’s not that sophisticated, but it works well and it’s zero maintenance for years.

Consider the Wright and complexity of the linkage forks, a leaf spring, torsion spring, or coil spring is a better bet. The Motion leaf spring was solid and functional, easy to set preload.

Maybe Bike Monkey would let you have it again now that you’re well?
  • 2 0
 Full VP bike front and rear called the flying carpet.
  • 4 1
 @jackalope: Even though I motivated then to raise their stupid concentric BB pivot, I'll never expect any props from them. Safe to say I cost them more than a few Demo sales and created some uncomfortable company meetings.

Nevertheless I still like the brand and this fork is a perfect match for high pivot designs on the rear if you want active, sensitive suspension. Just have to have the right damping so it doesn't dive or move too much when you don't want it to.
  • 2 1
 @SATN-XC: put it on the new Epic S-Works and it will be adopted just as quickly as the lefty was...
  • 1 1
 @mikelevy - You get comment of the week for this one.
  • 5 1
 Specialized collecting the patent is essentially a block on new linkage forks. New companies won't be able to afford the licence and Spesh probably won't even make it themselves.
  • 2 1
 I wonder if they're planning to apply the design to a gravel fork - even if the looks might have the more traditionalist roadies Laufing out loud. As we know one of the key features of Trust is fork offset being variable across the travel range unlike with telescoping forks where the offset is built in to the lowers and the crown. Interesting for hardtail riders for sure, but maybe drop bar users as well, as you could design the steering geometry without having to compensate as much with a slack head angle. I mean having something like 100mm of front travel with a fairly normal drop bar geo that's not garbage to ride on flat terrain but won't immediately squash down and throw you otb when hitting a pebble sounds like having the cake and eating it too to me?

Although personally I think you should just get a an xc bike at that point, but apparently the gravel crowd are willing to jump whatever hoops they can to remain apart from mtb as the whole Sram Xplor range points out Smile
  • 1 1
 @Spencermon: I see Roval wheels on a fair number of other brands bikes, could go something like that too.
  • 1 1
 @lacuna: Why would specialized, who doesn't manufacture forks, do this? Maybe Fox or RockShox, but what motivation would specialized have to limit fork choices?
  • 3 0
 @Protour: HE LIVES!!!
  • 2 0
 @hamncheez: Yes!!! This has made my day.
  • 1 0
 forkstlinkage
  • 1 0
 @shawndashf1: I think they are using their position as one of the Big 3 and making a gamble on a future product that could become a category leader if done correctly.

Buying the rights to the Trust IP saves them a considerable amount of time in R+D and testing, as they have a product that has been manufactured and proven, but might need further refinement, as this new filing indicates. It's shaved years off their development cycle and might have even saved them money, depending on the cost of the portfolio.

What they do with this fork is the big question. I think Levy is right in saying that aftermarket Spec products, save for basic accessories, are not widely-adopted enough to make this a viable aftermarket product, but I could be wrong. Based on the language in article, I'm going to guess that it shows up on Enduro-ish eBikes first as a way to firmly distinguish the eBike category from its non-electric forebears. It makes salesfloor and catalog marketing easier when you can point to a big visual difference in something and do the "you see, eBikes are like THIS while other bikes are like THIS."

As for my own bike. I like linkage forks and I hope this does go aftermarket at some point, but with Spec's track record on that, I will not hold my breath.
  • 2 0
 @monkeynaut: On the contrary, isn't the entire industry trying to make e-bikes look, feel, feel and sound exactly like a pedal bike?
  • 246 0
 "E-bikes are heavier and faster than typical mountain bikes. They are usually piloted by less skilled and less fit riders"

That's not what the marketing department says!
  • 139 0
 this is why they don't let the engineers issue public statements on behalf of the company
  • 25 1
 Yesterday I met a woman walking an ebike down a gravel road while wearing sandals. She could ride up, but was too afraid to go down. On the very same day I met a guy on an ebike who simply ripped, passing me as I was trying to recover between trail sections.
  • 1 0
 Oof!
  • 9 0
 "piloted by less skilled and less fit riders" jokes, was that quoted in the article from specialized or the patent write up? LOL
  • 29 0
 Haha. Specialized calling E-bikers out.
  • 24 0
 @BornOnTwo: it's in the patent! Fantastic self own.

Right after it: "In many cases the electric parts are large and unsightly"
  • 6 0
 ".......and reduces some of the drawbacks of E-bikes."

Some Electric Trolls here won't be happy......
  • 29 0
 @racerfacer: WOW I had to read it again for myself

"The disclosed wheel suspension assemblies are particularly well suited to E-bikes. E-bikes are heavier and faster than typical mountain bikes. They are usually piloted by less skilled and less fit riders, and require a stronger front suspension to handle normal riding conditions. E-bikes are difficult to build, requiring the challenging integration of motors and batteries into frame designs. In many cases, the electric parts are large and unsightly."
  • 1 0
 @suspended-flesh: some...not all...but I have the filter on now, you all do your thing
  • 16 1
 @SATN-XC: I also smoke Filtered Pinkbike 100s - Full flavor without all the unhealthy Electrons.
  • 32 1
 Specialized takes quote of the year with the unexpected scorching burn on their target market
  • 3 0
 I can see DW saying that. "My suspension designs are made only for those who know how to SEND."
  • 4 0
 That line made the entire article worth reading. Glad it was saved for the end.
  • 1 0
 @husstler ohh! Burned em!!
  • 3 0
 @BornOnTwo: Fox uses the same line to explain why the e bike forks use a lighter tune
  • 4 1
 Its a generalization but probably statistically correct. Strange how people don't see an issue of faster bikes being piloted by less skilled riders?
  • 1 2
 Good to know I'm not a usual pilot.
  • 11 0
 Pretty sure that part of the patent was written for (or maybe by) the Pinkbike comments section.
  • 2 0
 Actually theres a study that Boulder did finding that ebikers were on average slower than analog bikers: assets.bouldercounty.org/wp-content/uploads/2019/11/e-bikes-recommendation-bocc-11-13-2019.pdf
Anecdotally, I've found on steep downhill they're the same speed but on less steep they're slower. All of my top to bottom DH times on eeb vs analog the eeb is always a tad slower.
  • 3 0
 @piratetrails: I wonder if the ridiculous pro roadie level in Boulder skews the results?
  • 46 2
 I don't trust any of these.
  • 26 1
 What? I couldn't hear you. Could you say it again louder?
  • 26 0
 Is that the message you trying to get across…?
  • 19 0
 You don't have to shout.
  • 9 0
 Well Forxs, there you have it
  • 11 0
 Don't try to Weagle your way out of this conversation
  • 3 0
 Thrust and shout.
  • 1 0
 If only we knew what the linkage between Levy and specialized was
  • 32 1
 Can’t wait to see Specialized brand these as S-Works and they become even more expensive.
  • 5 3
 not gonna happen - S-Works is for weight weenies and linkage forks weight a ton
  • 3 0
 @f00bar: But it says they'll be lighter. I wanna weenie!
  • 2 0
 Companies don’t buy IP purely to profit from the tech… often it is to eliminate the potential competition. Don’t expect to see a specialized truss fork anytime soon.
  • 2 0
 @blackthorne: specialized isn’t really in the fork competition though. If fox or rockshox bought it that would make more sense.
  • 1 0
 @Austink: They could do what they do now, which is license their tech (eg, Brain, Autosag) and have the big cats build them.
  • 25 0
 They could call them 'Lumpumpers' or 'Rockstoppers'
  • 7 0
 Forst linkage?
  • 3 0
 Fork bar linkage @sngltrkmnd:
  • 2 5
 They should call them shitilized epic
  • 23 0
 They spelled "purchased" wrong in the headline
  • 6 0
 How I actually went back up to check
  • 21 0
 Get one on the grim doughnut ASAP.
  • 18 2
 Hmmm...Didn't know you could patent ugly.
  • 13 2
 Filed somewhere between Steve Buscemi & Janet Reno.
  • 13 0
 A Grim Donut with this abomination up front and a gearbox belt driven rear end with a honky horn and streamers. Free spandex with every online order.
  • 12 0
 So Specialized filed a patent and used an old Santa Cruz 5010 bike in the drawings...
  • 3 0
 Somewhere...Café Roubaix is having a laugh.
  • 1 0
 Definitely a tallboy 3. No upright on the drive side of the rear triangle.
  • 1 0
 And wtf is up with the handlebars in the illustration
  • 1 0
 The upper jockey wheel on the rear derailleur....no wait, there is no derailleur, it's just a cage floating in space and even that hasn't been done right.
  • 13 0
 FSR in the back, FSR in the front! FSR all the things!
  • 1 1
 Actually fsr in back, DW in front.
  • 18 9
 Specialized gets the patent on something they didn’t design or contract out fir design. I wouldn’t be surprised if Specialized sued Dave Weagle for still having his name on the patent.
  • 4 2
 When a company has a product and another company wants it/ sees that they could use it to make some money, they buy it. It is normal. Look at Outside buying Pinkbike.

Also, who cares about the patent. Companies take over patents all of the time.
  • 5 0
 I sincerely hope specialised immediately sues anything and everyone that has ever existed that has the words "Linkage", "Fork" or "Design" in its name. It's long overdue and Specialized is clearly entitled to damages and loss of reputation from those miscreants who have foolishly invented such things.
  • 1 0
 What struck me most is that Park Tool holds a patent on blue tool. I've got some blue tire levers from Schwalbe (because their company color is blue and it even says on these tire levers, that the color blue belongs to Park Tool. Unior makes blue tools too but I understand they aren't blue in North America. Actually Tacx has blue as a company color too and until Garmin acquired them, they made loads of tools. Not sure whether it is because of Park Tool but these weren't blue (as far as I can remember). Not sure whether Park Tool is even older than Unior, but it is kinda silly isn't it? There are only so many (clearly distinguishable) colors available. Regardless of the amount of R&D that goes into it (if any), can a brand just define a niche market (bicycle specific tools) and patent a color?
  • 1 0
 @vinay: are you sure the color isn’t trademarked? It’s hard to patent design choices that don’t affect function or performance in a novel way, typically those types of things are trademarked instead.
  • 1 0
 @bikeracer28: Well yeah, you must be right. I just checked and couldn't find anything molded/written in these levers so it must have been written on the packaging. But it is probably as you said, trademarked not patented. Still not sure how it works with trademarking a color. Could anyone just do that? A color is much easier to recognize than a logo or name so if say Grimeca trademarks red brake calipers, no one else is allowed to do so without mentioning their name (even though they no longer make brakes for bicycles)?
  • 1 0
 @vinay: they can certainly try. It's only successful to the extent that the market doesn't challenge it.
  • 1 0
 @vinay: The term you're looking for is Trade Dress and is similar to a Trade Mark. It essentially covers all the ways in a which a product is packaged, and the appearance of that product and/or package. Lots of brands have color(s) protected under this, with Park Blue (actually several shades) being the best example in the US bike industry.

T-Mobile Pink is another similar example. I'm going to guess that McDonald's Yellow and Red are also covered, but I don't have to time to look that up right now.
  • 10 0
 “… be unleashed at a more reasonable price point.”

Because that is what Specialized is know for, right?
  • 3 1
 actually the lower end models are priced quite well... SWorks on the other hand.
  • 3 1
 @jaydawg69: sworks 500 cheaper than similar spec Yeti and 250 more than SC… Enduro vs SB150 vs Megatower. I wouldn’t call that crazy relative to what everyone else is doing lately. Hell a top off the line Trek Slash is 1000 more than the Specialized.

(Yes I own a new Enduro… Comp)
  • 6 0
 "E-bikes are heavier and faster than typical mountain bikes. They are usually piloted by less skilled and less fit riders"

Surely this is offensive in this day and age! hahahaha.
  • 3 2
 Maybe offensive, but mostly true
  • 8 0
 Coming to a gravel bike near you!?
  • 3 0
 you're probably right
  • 5 0
 The problem with the Trust isn't the weight, it's the lack of comfort and plush through choppy ground. It corners like nothing else and it could be a clear advantage. Please Specialized, make a 'comfy' Trust Message.
  • 5 1
 I rode a Trust fork.

The objective, rational side of me said: "It actually works, and does so very well."

The subjective Pinkbike forum fanboy who shoots his mouth off first, does his homework second says, "Hell naw, I ain't riding that, my bikepark bros would totally dis me."
  • 1 0
 Yup. That's the hurdle to overcome for market acceptance. Physics is on the side of linkage forks over telescoping, especially as headtube angles get slacker and slacker. But as long as people can't imagine one hanging off the back of a Tacoma, it's a non-starter.
  • 7 0
 What the hell, I don't see this one on Wheelbased either.
  • 6 0
 On vacation. Was holding on to it.
  • 20 0
 @WheelBased: But how did PB get something about patents without copying from you?
There was another one recently that you still haven't covered.

So when you post this will you cite PB since you are obviously copying them if you post it now?
  • 7 1
 Ebikes "They are usually piloted by less skilled and less fit riders"
Ain't that the truth!
  • 6 0
 Good to see Specialized has stuck to its business practice origins.
  • 3 0
 This is like a Sci-fi movie when the huge Praying Mantis like alien gets killed at the end and then a evil scientist resurrects it for the sequel.

( jokes. I actually liked the way the Trust looked)
  • 4 1
 This is great. I've been pretty psyched on most of the new specialized bikes, so it'll be good to get back to bitching about them when they have a stupid trust fork on the front.
  • 1 0
 What do you do about the fact tha your carbon rims are insanely overpriced? Turn the tables by calling yourselves ENVE.
What do you do if no one trusts your design? Paper over people's worries by calling yourselves TRUST, of course. (That said, I was and am enthused about these forks.)
  • 5 0
 The VPP design on the patent may be the more interesting part
  • 1 0
 Sounds like it will be really convenient to get serviced. If it's anything like Brain shocks and cartridges, they intentionally make it very difficult to get service, and only do so directly. They don't sell parts or have alternate service workshops.
  • 1 0
 Nice patent, only it has nothing doing.
If there would be better practical solution like then the tradional for design, the enduro, motocross, motoGP, superbike...every motorsport would used it, but all of them uses the traditional supsension type.
Nice try from Specialized, but it will be a big failure IMO Big Grin
  • 1 0
 As far as I know, Hap Seliga, one of Trust Performance's co-founders is currently at Specialized. I'm sure he had some influence in Specialized's acquisition of Trust Performance IP and trademarks. I heard from another co-founder Jason Schiers himself that TRVSTPER Inc IP was sold off to an undisclosed entity a little over a month before this article came out.
  • 1 0
 I own a Trust Message and have ridden it for the last two years and love it. It is not as plush of a ride in rough sections, but I feel like I have more control. And for cornering, nothing tops it. I’m glad to see Specialized was able to pick up this patent and am hopeful that they will do something with it. I’d love to see this back on the market. Oh yeah, as far as the looks go, it definitely grows on you. Wasn’t a huge fan at first, now I think a telescopic fork looks silly.
  • 5 0
 Looks like a Message.
  • 4 3
 A genius simplifies the complex, and idiot complicates the simple. No idea how this is any better than a current pistonic fork. More weight, pivot points to wear out and create slop.....and what if you hit a rock hard?
  • 13 1
 Because current telescopic ("pistonic" is not a word) forks never have bushing play (or bushing binding), nor do they creak, piss oil out of the seals, or require maintenance all the time. What IF you hit a rock hard? Well assuming you mean if you crash your fork onto a rock, with current forks you destroy a sliding surface or punch a hole in thin magnesium lowers, they aren't exactly bulletproof either. Never mind the friction...
  • 5 0
 @Socket: your description is giving me PTSD from riding suspension forks in the late 90’s.
  • 3 0
 @Hayek: hahah things have not changed all that much really, all the same problems exist, they're just scaled down a bit.
  • 2 1
 @Socket: I rode some of those forks and shocks that would 'piss oil out of the seals' (Risse, FMF, 1st gen Fox, RST, Mag21s, Judies) but I think its a thing of the past - I haven't seen it happen since the death of open bath damping. Nor knocking from worn bushings, stanchion wear (when maintained) etc. Modern forks are pretty reliable.
  • 9 0
 @iamamodel: we see all of those problems @socket mentioned in our workshop on a daily basis. Less oil comes out of the seals nowadays because there's much less oil in there (if you lose 10ml of oil out of your fork lowers, you might have lost 100% of the oil!), but I have to think that anyone who doesn't see faults in telescopic forks just isn't paying very much attention. It's just that all the telescopic forks have basically the same problems, so one product usually isn't markedly better or worse than another.
  • 2 0
 @VorsprungSuspension: Fair enough. Do you think linkage forks will have fewer problems?
  • 2 0
 @iamamodel: FWIW, complex linkages are common in the rear nowadays. For example the specialized Demo and Enduro. Aside from the frame bending or breaking, the only problem you'd have is bearings getting worse. Otherwise it is the shock.

Linkage forks are similar although this one has multiple internal damper pieces.

If you want to see the potential positives a linkage fork has, see this article:

m.pinkbike.com/news/review-six-months-on-structures-wild-looking-cycleworks-scw-1.html#descending

Quote from article: "The linkage suspension on the front of the SCW feels impossibly smooth throughout its travel, almost enough to make me think conventional forks are filled with a 50/50 mixture of sand and maple syrup for lube"
  • 7 0
 @iamamodel: That's a fair question, but it's pretty hard to generalise linkage forks in the same way you can generalise telescopic forks, for a couple of reasons:
1. All telescopic MTB forks are by necessity nearly identical (many of them even use the same SKF seals in different diameters for example), whereas there's a huge variety of possible configurations and executions of a linkage fork, so even the term "linkage fork" is about as generic as saying "bike frames". Some frames have very few issues, some have many, it depends on the details of the design and execution, so it seems reasonable to expect the same variations within linkage forks, and tarring them all with one brush isn't likely to be accurate.
2. There's a ton of telescopic forks on the market that are sold at enormous scale that all have to deal with all the issues mentioned (with varying degrees of success), so we (as a market/industry) have seen exactly what does happen, whereas with linkage forks that don't really exist on any large scale currently all we'd be doing is speculating. I don't think it's really reasonable to say that linkage forks necessarily have more things that can go wrong though - my telescopic forks have usually required more maintenance than my frames' linkages + shocks, but a couple of less-than-ideal frames and shocks have been the opposite too. A well built linkage fork might be the most reliable fork out there, but a less well-built unit might be a total POS too.

I think what @mdinger said is pretty accurate though (and having ridden the Structure I'd agree that it straight up outperforms telescopic forks). I'd love to see someone do a stand-alone linkage fork well, but I think it's a lot harder than a telescopic because you have way more variables to balance, and even if you got the performance, cost, weight, reliability etc right, 90% of riders still wouldn't be interested, partly because of healthy skepticism, partly because of unjustified cynicism, and partly because it's just kind of jarring to try to get your head around a bike that looks that different.
  • 4 0
 @mdinger: We appreciate the nod and agree with everything @VorsprungSuspension has to say about linkage vs. telescoping forks.

We have many tens of thousands of hours on our WTF Linkage system, and stand behind it with more confidence than ever. It's tough, smooth, slack when you need it; steep when you need to maneuver, and best of all has no bushings, seals, oil, springs, or dampers in the fork at all. Many of our bikes have thousands of hours on original frame bearings. We also know with zero doubt which suspension type requires more service, and it's not ours.

Nice to see Specialized pick up the Trust patent, and we hope they'll release models with linkage forks as optional.

That being said, we are *extremely* confident in what we're doing at Structure and have big plans for full-linkage bikes of many model types in the future (apologies to the haters)
  • 1 0
 @VorsprungSuspension: Having taken apart both the Trust Message and Trust Shout forks, there are a number durability related items to note. Most of the riding stresses (longitudinal and transverse) of the compression are held at the pivots as opposed to the strut leg, which reduces bushing wear at the damper unit. However the weakness of the Trust fork is apparent when the wheel experiences a side load (off camber landing) or huck landing in which there is unequal resistance in compression due to the damper being on the right side can cause the fork axle level to twist laterally exposing the strut plunger to bending forces in extreme cases. I think they could've used indexed needle bearings on the strut plunger on both the left and right airspring/spring-damper like those used on the Lefty and double row bearings on the lower linkage to mitigate the twisting moment on the fork's travel while maintaining suppleness. I also think that using a 20×110mm thru axle may have helped improve the rigidity of the fork as the linkage legs can move independently of each other.
  • 1 0
 @EdgarDacanay: is this visible on the bench just testing by hand or did you just see evidence of wear?

If you increased the stiffness of the bearings, wouldn't the need to have springs on both sides reduced? Like if it was built as a single sided lefty for example.
  • 2 0
 @mdinger: Assuming the thru axle is tightened properly, a perpendicular compression test against a kerb or wall would show a slight but noticeable deflection of the wheel to the right with a left deflection on rebound. This is because the linkage arms can still be "elastically twisted" kind of like how the left and right sides of a Horst link rear suspension can momentarily be twisted. Also when the thru axle is removed, each side can be moved independently of each other and a considerable torsional deflection of the linkage assembly can be achieved by twisting the carrier link by hand. Designing in double row bearings in the lower link on the strut plunger end as well as indexing the plunger with 3-position needle bearings would help reduce the lateral deflection of the trailing link by allowing some lateral forces to be transferred to the strut. The design improvements I listed above would be necessary for a Trust-lefty fork design because beefing up the linkage bearings and linkage arms would not be sufficient to provide the torsional strength qualities for aggressive trail riding.
  • 1 0
 @EdgarDacanay: that's cool! Thanks for the clarification!
  • 2 0
 Yes, because Specialized definitely isn't known for producing ludicrously expensive stuff.
  • 2 0
 Expensive retail doesn't mean it isn't cheap to produce. A SPESHalty of their's!
  • 6 0
 is there a contest between linkage fork designers about who can come up with the fugliest fork?
  • 3 0
 @f00bar: it's about owning marketspace... They can own the patent and just kill it if they want. How many patents does Specialized own that never made it into production?
  • 1 0
 If there’s a place to store tools and stuff in the frame you can’t even see it on the drawing. that’s probably a very lean cage
  • 2 1
 "Perhaps with the capital, scale and expertise of Specialized, the full potential of the linkage fork will be unleashed at a more reasonable price point." Nope. Wrong brand.
  • 3 0
 $25k E-bike with linkage fork, here we come.
  • 2 0
 Just wait for the new s works epic with a carbon linkage fork. Only $25,000!
  • 3 0
 specialized specializes in a special suspension design
  • 1 1
 No!!!!! Please make it stop…..

Spesh like doing their own suspension forks/shocks for one reason only - cost. Buying the intellectual property from a failed venture just underlines this.
  • 3 0
 Looks like MikeBike consulting is already paying dividends!
  • 1 0
 Specialized with comment gold - "E-bikes are heavier and faster than typical mountain bikes. They are usually piloted by less skilled and less fit riders".
  • 1 0
 Put it on your bikes specialized. With shit butchers. A bloody wu-dropper and your ultra stiff carbon rovals with formula hubs. That's worth 15k easily. Do it. Do it.
  • 1 0
 - Can we somehow justify adding $3k to our bikes, please?
- Trust me: We Can!! And if we put a "BRAIN" sticker, it'll be another grand!!
  • 3 3
 I have no Trust in linkage forks, must need some Specialized skills to handle that thing. Shout out to who ever is able to ride that thing comfortably.
  • 1 1
 The fork on the old enduro shown there was made by Maverick if I remember correctly so it’s hard to say that it was in-house suspension.
  • 2 0
 Maverick had a different fork, the DUC 32, which was an inverted fork. The fork pictured on that Enduro is a Spec E150.
  • 1 0
 Gotcha. I remember the DUC as different but thought that maverick was where I had to source seals for the e150 I had and when they went under there were no new ones being made. My mistake.
  • 2 0
 It looks as if the front hub developed a tropical fungus. A nasty one.
  • 1 0
 If you don't continue development, how else will you sell bikes for $6900+?
  • 2 1
 sold out to The Man. guess they of all people never ripped off his linkage designs, so there's that.
  • 3 0
 The perfect thing to sell to a big company... I don't blame him at all. The man can have it.
  • 6 4
 Looks like… half of a Session.
  • 1 1
 hhahahaahahah wow this comment needs way more upvotes, i spit my coffee at the computer over this one lol
  • 2 0
 Well shoot, I guess that confirms Trust isn't coming back...
  • 2 0
 That old Enduro looking nuts these days
  • 1 0
 Looks a lot like my patent from 21 years ago...

patents.google.com/patent/US5899478A/en?oq=woodside+terence
  • 1 0
 The best thing about most patents is that it stops someone else making to same mistakes. E=Mtb²
  • 2 1
 Still not as interesting as Yeti patenting a derailleur.
  • 3 1
 God please no
  • 2 1
 @whattheheel: the dream lives on under the evil S empire
  • 2 1
 Reads to me more like a "capture and kill" patent scenario.
  • 1 0
 Marketing = the new thing... rinse and repeat. Punters lap it up.
  • 2 2
 I Trust that nobody got the Message the first time around but there’s no need to Shout about it either.
  • 1 0
 We will see on a Demo next World Cup season cause sales
  • 1 1
 No thanks but I need my stuff to look good as well. That thing is awful looking!
  • 2 1
 You could pay me and I wouldn’t put this on my bike!
  • 2 0
 For kicks, how much would you need? Be honest.

I'd put it on if there was no weight penalty and no price difference. Which means I'm safe for... ever.
  • 1 0
 Trust that everyone gets old and ends up on a rigid single speed.
  • 1 0
 Brand new trust msg forks on eBay for 800!!!
  • 1 0
 I took apart both the early batch Trust Message forks, Message fork with updated air spring and damper assembly and the Trust Shout forks. The early batch forks (noted with a -D suffix in the part number on the box) has an air spring cap that needs special flat wrenches to take apart whereas the updated spring/damper assembly can be taken apart easily with a decent mechanics tool set. The Ebay offerings are likely unsold initial batch forks as I bought one of my Trust Message forks from there.
  • 1 1
 Another patent stashed away by Specialized so they can sell licences and/or sue people in the future. Great.
  • 1 0
 The same performance at double the cost, what could go wrong!
  • 2 0
 Fork in hell
  • 1 0
 High pivot bikes with linkage forks
  • 1 0
 Feel like gravel bros would friggin love a 2inch travel linkage fork.
  • 1 1
 I hope that specialized uses this to responsibly never allow a linkage fork to ever be made again
  • 1 0
 Linkage forks are the Afghanistan of bike technology
  • 1 1
 When does the dual crown version drop?
  • 3 0
 They would need to buy the Girven fork patent from the 90's.
  • 1 1
 @insertfunusername: patent is only good for 7 years then copy away
  • 2 2
 Stop it. It's already dead.
  • 2 2
 Jesus specialized, isn’t your warranty department tired???
  • 1 0
 Looks like a trust
  • 1 0
 Theres a ding dong there
  • 1 1
 I honestly wouldn't even put that on my bike if Specialized paid me to.
  • 1 1
 hmmmmmmmm perhaps not
  • 1 2
 OOOHHHH BOOYYY..... HERE COME THE COMMENTS.........
  • 11 0
 Yup, the clue is in the name... it's the comments section.
  • 1 1
 I beg your pardon.
  • 1 1
 Nope. Just nope.
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