The Story Behind Push Industries' Prototype Linkage Fork

Sep 22, 2021
by Matt Beer  

When a grainy photo of a linkage fork appeared on Push Industries' Instagram account a few weeks ago, it caused a bit of a buzz around the industry, in part because the news of Specialized's acquisition of Trust's linkage fork patent came out just a few days prior. There have always been those homegrown trade show contraptions or student engineering projects that appeared on the slopes of Whistler Bike Park, but for these names with a lot of clout in the bicycle biz, it made us think. With their ability to dictate axle paths and anti-rise characteristics, are linkage forks the future of mountain bike suspension technology?

Push Industries has been well known for their tuning and aftermarket kits for some time, but when they introduced their ElevenSix shock, it raised the question - what comes next? Building a rear shock is easy. Simply throw a block of aluminum into the CNC machine, pop in your favorite shim stack, slide on a suitable spring, and voila. Sure, there's A LOT more to it than that, but a fork on the other hand takes a large investment magnesium cast, that is, if you build a traditional fork with one-piece lowers.

It might look like a desktop daydream, but Push actually began prototyping the fork you see above in late 2015. The inverted, dual-crown chassis is also linkage driven. Based on the Earle's Fork patent, used on BMW motorcycles from 1955 to 1969, the leading link design features a link arm main pivot that rides on the lower leg while the dropout is attached separately. Behind the stanchions is not a fender, but another arm bridging the link to the upper tubes.

If you can imagine the front axle moving from the 5-o'clock position up to 3-o'clock, then you understand one concept of the Earles fork: a lengthening wheelbase. The prototype also tested anti-rise levels that are induced by the brake forces, but unlike traditional forks, it can cause the front end to rise under hard braking. USD forks are susceptible to lateral deflection, but the Earles concept helps to stiffen up the steering.




We reached out to Darren Murphy at Push to see if we could get more info on this early design:
bigquotesWhile good in concept, we ultimately felt that telling the story behind the design was going to be too large of a hurdle for a small company like ours. Additionally, there would be some packaging issues because at the time we didn’t have the technology to package the fork in a single crown format. We felt that hurdle would limit its ability to be widely accepted.

The final strike really came in early 2016 when we first learned about the newly formed Trust Performance. I’ve known Dave Weagle for many years and have a lot of respect for him and his work. After a few conversations with Dave, I really felt that Trust had the legitimacy and support to move forward with their linkage fork design. At that point, we archived our design and started to discuss how we might be involved with Trust from a sales/tuning perspective after their public launch. Ultimately those talks fell short for a number of reasons.


Plenty of riders appreciated the qualities of their Trust linkage forks and I would have loved to try out the Earles concept fork myself. I'm certain Darren and his team learned a lot through that development process, tangible projects aside. So, does that mean we will see another fork prototype from PUSH and what will it look like?

When we prodded Darren more about the idea of a production fork, he was tight lipped about the chassis construction, materials used, and a timeline, but did go on to say:

bigquotesAt this point, Push offering a fork to complement our ElevenSix rear shock is probably the worst kept secret in the industry. Our recent Colorado factory expansion more than doubled our manufacturing capacity, but even with that we have several challenges still ahead of us with a project of this scale. While I won’t commit to a specific timeframe, I will say that our ElevenSix customers will be the first to know! - Darren Murphy, Push Industries



162 Comments

  • 129 7
 It violates the KISS principle and is a contender for the "Pontiac Aztek Beauty Awards."
  • 18 0
 GM really one-upped the Avalanche with that beauty didn’t they. Made K-cars look hot AF.
  • 6 0
 KISS and cost are the reasons I have little interest in this type of fork for my own personal use. Regarding looks, I think this fork is much better looking (at least there is a form follows function argument to be made) than the Aztek.
  • 10 1
 @westeast: it may not look pretty, but 3 pivots, all externally accessible seems like a good way to KISS. Performance benefits/ negatives aside..
  • 1 0
 @mkpfaff: Yes ... lol
  • 11 0
 Walter White would ride.
  • 2 0
 Pretty bad to be compared to an Aztek over a Rendezvous.
  • 4 0
 Have you seen the Fiat Multipla?
  • 21 5
 This comment chain is why companies aren't bothering with new tech these days. Looks are obviously the priority, and looking like a Session is the best you can do. Honestly sad. Incredibly superficial.
  • 2 0
 @RGonz: As long as you ignore that it is 3 pivots, per side, as well as all of the parts that make up a telescoping fork. That being said I would love to try a fork like this.
  • 10 0
 In my experience, people who talk about the KISS principle are the same kind of people who don't know how to export to PDF and tuck their shirt into their jeans.
  • 5 0
 I think it looks fine but I upvoted just because that was funny as sh*t.
  • 3 1
 @pgomez: Who tucks their shirt into their jeans? I get wearing a suit but the only people around me with shirts tucked into jeans are also wearing shit kickers and a fancy belt buckle. Brimmed hat vs ball cap depends on how bro cowboy they are.
  • 114 20
 I'd make a Push to Trust this fork more than anything Specialized is producing.
  • 5 39
flag FastRiding (Sep 22, 2021 at 18:56) (Below Threshold)
 Their products are unreliable as fu kk
  • 1 10
flag CliffRacer (Sep 22, 2021 at 22:22) (Below Threshold)
 lol specialized gonna buy out the ip of another insolvent company for pennies cause that company wanted to make a linkage lefty. Good that my next stumpy will have an 11-6 stock.
  • 14 1
 @CliffRacer: totally different, this one's a righty.
  • 3 0
 @subwaypanda: Cool! Wifi brake adapters with floating rotors!
  • 50 1
 It’s just a heavier version of the USE SUB fork from 19 years ago
  • 6 0
 Damn. good memory.
  • 3 0
 Well done. Ha- It’s like 2 sub forks in one
  • 5 0
 That's what I thought about right when I saw the thumbnail. Patents expire in 20 years, right? Seems like it will face the same challenges as the USE SUB anti-dive fork had. That is, it is made to not dive when you apply the front brake (as for the suspension to compress the brake caliper has to rotate against the front wheel rolling direction). Which inherently implies that braking will affect suspension performance hence front wheel traction. That's the difference with Trust where the link with the axle and brake doesn't rotate as much.

Either way, good to see brands pull old expired and unused patents from the mothballs and actually do something with it. Looking forward to the day that a brand just picks that old PeteSpeed gearbox patent that Hayes bought from B1 and never did anything with. Could easily be the cheapest internal gearbox that people have been waiting for.
  • 1 0
 Always wondered what happened to that gearbox design @vinay:
  • 3 0
 @NatuRaOx2: Last thing I recall is B1 (a spin-off of Batavus, an Accell brand) got sold to an American company (Bloom-something) and the American company cared shit about bikes so B1 soon got out of business. The PeteSpeed patent got sold to Hayes but Hayes did nothing with it so far. One possible reason could be that the super secret Honda gearbox (in their DH bike at the time) was more or less the same so Honda couldn't use theirs in a production bike but may have also made a deal with Hayes to not do anything with it too. But that's super pure speculation. I just think it is odd that they never did something with it as at the time the world had really big expectations of gearboxes. So yeah, maybe the patent will expire soon and someone pick it up and actually build it. It is so simple, I can imagine someone could realize it with some basic tools. Unlike Pinion and Effigear, it doesn't require special gears. Just an aftermarket cassette and pulleys.
  • 1 0
 Beat me to it memory man - I used to drive ( not ride) a Harley with leading links 30 years back - can testify to their anti dive on braking and just way stronger on cornering on 3 or 2 wheels and yes butt ugly.
Almost went with Trust just as they shut so hanging tight for now.
  • 28 0
 Wait my armchair PB based engineering degree has taught me that rearward axles path = good. Is it me or does that fork have a forward axle path?? Or at the very least, less-rearward than a traditional fork. Will the new marketing campaign say that a forward axle path lets you attack your obstacles more aggressively? Is this the way for an ultimate downduro build?
  • 2 0
 The Trust Message axle path is engineered like a Horst Link style suspension. This seems to just be moving the axle forward through the travel.
Oddly enough, the Message (and Shout I assume) moves in a mirror image to this.
  • 7 0
 By moving forward under compression, it reduces dive. It also puts the wheel farther out front in big hits, so youre sacrificing comfort for stability. At least thats what I imagine, I'm not a professional.
  • 5 0
 Adjustable axle path... just turn the tubes around in the upper crown!
  • 1 0
 It’s proactive, not reactive
  • 10 0
 @ExMxEr: the message was designed around maintaining constant trail throughout the travel. A telescoping fork reduces the wheelbase as it goes through it's travel.

Hence this could depending on configuration:

* Keep wheelbase from reducing much
* Maintain wheelbase
* Grow wheelbase through travel

@ironxcross comparing rear axle path on the rear suspension with a telescoping fork and a linkage fork is quite complicated.

A rearward rear axle path actually increases bike stability because the wheelbase increases length while going through the travel. A rearward front axle path decreases bike stability conversely.

The steering makes the front extra tricky because while the bike may be more stable the steering may become more or less sensitive at the same time. This depends on trail.

Hence the devil is in the details and you can't just say "rear is always better".
  • 26 0
 Higher rearward axle = higher profits! C’mon you were at the seminar.
  • 3 0
 @mdinger:
The Trust Message changes trail through it’s axle path.
  • 52 0
 Axle path is only one of several parameters when designing a linkage fork. Three design mistakes that have doomed most linkage forks:

1. 100% anti-dive. Telescopic forks have roughly -30% anti-dive (30% pro-dive), so there's no need to go all the way to 100% AD, especially when high AD introduces other issues.
2. Rearward axle path. A linkage - especially one without any telescopic elements - reduces friction so greatly that even a more vertical axle path can transmit less force to the rider's hands. In the case of the Trust forks, their axle path was too rearward (initially), leading to poor compliance.
3. Weird motion ratios. For rear suspension, a lot of R&D has gone into developing a narrow range of spring and damper curves that work with a narrow range of motion ratio curves. Many linkage forks have used wildly different motion ratio curves and either attempted to couple them to equally wild spring and damper curves, or just used traditional spring and damper curves and hoped for the best (spoiler: the former rarely works and the latter never works).

The challenge with designing front linkages is to balance all the parameters, of which there are many more than with a telescopic fork, and there's a lot less R&D to draw upon as a template.

It becomes even more complicated if the linkage is integrated into the chassis, as opposed to plugging into a standard head-tube, but the potential for performance is even higher.
  • 4 0
 @R-M-R:
Fantastic breakdown!
  • 1 0
 @ExMxEr: Thought the claim was constant trail throughout travel. Oops. Guess I remembered wrong.
  • 10 0
 @mdinger: Even if a claim is made for constant trail, clarification is needed:

• Is it constant in heave or pitch? Can't be both.
• Why should it be constant? Maybe there should be less trail at full extension, for lighter steering feel under light loads, and more trail when compressed (again, need to discuss heave vs. pitch) for more stability when you're really getting after it.

The former shows a poor understand and/or poor communication of dynamic chassis parameters, and the latter hasn't been fully explored because the R&D on linkage forks is so much less than that of telescoping forks.
  • 1 1
 @R-M-R:
I need to come clear- I’m building a new Tallboy and I’ll be using a Trust Message fork.
As my handle implies, I’m and ex motorbike racer, and I’m always looking for a way to get my low travel bikes to handle like a motorcycle. Low travel because I climb out of the saddle, so I feel the anti-bob of the Message kinda offsets the weight.
My downhill style is extremely loose at the bars, so I’m hoping the harsh ride won’t be as much as an issue.
Everything else about it sounds perfect, and they can be had barely used for under $700!
  • 2 0
 @R-M-R: eh what do you know about designing linkage forks?? Wink
  • 7 0
 @hamncheez: Less than I wish I knew, but it'll have to do. Wink
  • 1 0
 @R-M-R:

30% pro-dive for telescopic forks? I thought is was more like 90% pro-dive? I’m just going from memory though and could well be wrong.
  • 1 0
 @R-M-R: thumpertalk.com/forums/topic/1350345-dual-front-suspension-system-on-a-ktm
Have you seen this?

In a different thread he states that at full extention its got more trail than a conventional fork and compressed its got less.
thumpertalk.com/forums/topic/1299008-hossack-and-girder-telescopic-fork-hybrid-suspension
  • 2 0
 @TrueScotsman: Yes, 30%.

@englertracing: I'm a fan of independent-axes systems, such as the Hossack, which is what I prefer for my own designs. Can't say I favour the hybrid, though - why have two complete systems when all design goals could be achieved with just a Hossack? In any case, I favour trail increasing with compression for mountain bikes because mountain bike chassis are often pitched forward during descending, which is when the handling is most vulnerable to instability. When the lower steering axis (fork) is independent of the upper steering axis (stem), it's possible to have increasing trail while preserving front-centre length.
  • 4 0
 @jefe: sideways axle path for the adventurous ones amongst us!
  • 3 0
 @TrueScotsman: Well ... I complain when others throw around numbers, so I should expand on that. We can never give a universal answer for anti-squat, anti-rise, anti-dive, etc. because they depend on the geometry of the vehicle, rider posture, and - importantly - the attitude of the chassis. At full droop (topped out, static geometry), the anti-dive of a telescopic fork is very different from the anti-dive at full pitch. The chassis attitude of a fully rigid bike doesn't change, while the attitude of a bike with lots of travel can change considerably.

Also ... I made a mental error. I was recalling one of my front linkage configurations that had 30% less dive than a telescopic fork at a certain point in the stroke. That configuration had a little pro-dive at full droop to allow some weight transfer and "soften" the brake force, therefore the tele fork has more than 30% pro-dive at full droop. Apologies for the error. The tele fork isn't as bad as 90%, though.

There will be more pro-dive on a fully extended telescopic fork with a slacker head-tube angle, longer wheelbase, and/or lower centre of mass, so a motocross bike could have an extremely high pro-dive value. I don't know the combined CoM location precisely enough to say whether a motocross bike has 90% pro-dive at full droop, but it could be possible.
  • 4 0
 @Mac1987: I see you've ridden the Marzocchi Shiver SC. lol
  • 1 0
 MTB suspension has shortened the wheel base of bikes as they go though travel
So does this change that ?
But does seem some errors with this linkage design for it to work?
  • 1 0
 @mdinger: With the axle going forward, the trail will decrease and the steering will be nervous. Thats something to consider. But also, reducing head angle via frontal impact only will reduce trail too.
  • 2 0
 @ExMxEr: Get an E13+ Motion Ride instead of a Trust, you’ll thank me later
  • 2 1
 @Notmeatall: Since when a normal sus fork compresses the head angle gets steeper so if fork moves forward then compressed then headangle should remain closer to same angle?
  • 2 0
 @Notmeatall: You're correct that moving the axle forward will reduce trail. A fork flexing rearward, however, will increase trail.

@aljoburr: Moving the axle forward does not increase the head-tube angle, it increases the offset, which reduces trail.
  • 1 0
 @R-M-R: you are totally correct about the problems of giving universal numbers to anti-dive/squat/rise as they are so dependent on rider and bike position. Saying that, there has to be some sort of benchmark values if only for comparative use.

As for my initial figure of around 90%AD- I have now realised that you were right and that value was more attributable to motorbikes with their lower CoG. A gravity-focused mtb at full droop with rider in a neutral position (whatever that is!) is likely to be closer to 60%AD* (back of an envelope workings out)

I also agree with you that a linkage fork would be better with some pro-dive or at least 0% AD (at sag?) if only to provide a familiar feeling to the rider. It will also help reduce ground trail that may be beneficial with initial cornering turn-in.
  • 2 0
 @TrueScotsman: I calculate less than 60% pro-dive at full droop, based on my CoM for a size Medium to Large male rider on typical "trail" category geometry, but we're clearly on the same page and our numbers are close enough for the current discussion.

You're correct that a more familiar feeling is initially welcomed by most riders, but maybe optimial performance could come from a bike that feels less familiar. Just as a 2021 bike would feel alien to a 1990 rider, maybe the "ultimate" linkage front end would require adaptation. Maybe tire design could change a little to modify the initial braking and turn-in properties, affording more room to optimize the fork kinematics. There are so many variables and there is so much room for optimization, especially with linkage forks that use decoupled steering axes.
  • 1 0
 @R-M-R: Lots of truth in this. Cathro interviewed Minnaar when Minnaar moved to those 460mm chainstays, and they talked about tall guy bikes. When Cathro was first sponsored like 15 years ago, his company said they would make him a custom sized frame, and he originally came up with something that wouldn't be out of place today (he is 6"9' or something) but he chickened out and just went with the stock XL size they had. Minnaar said that if they could time travel and send a modern bike back then, no one could ride it fast, or would want something so long, low, and slack. Riders, riding styles, and tracks weren't ready for it yet.
  • 1 0
 @ExMxEr: True question: if you want your MTB to handle like your moto, wouldn't you go for a telescoping fork? Have you ridden a Trust?
  • 1 0
 @hamncheez: Yes, both the equipment and the riders have to evolve together. There will always be some limiting factor. For example, in the 1990s, tires improved and front - occasionally rear - suspension was introduced, but geometry and brakes lagged. There were even some sticky(ish) tire compounds, such as Specialized Umma Gumma and Tioga ... whatever they called the tan compound. A 63° head-tube angle would've been useless without better suspension. 170 mm of modern travel would've been useless without the geometry. Both together still would've been useless with cantilever brakes - not to mention 580 mm handlebars, drivetrains with terrible chain retention, fixed-length seatposts, 1.8" tires (that claimed to be 2.1"), etc. Even a full 2021 bike would've been a fish out of water on many of the trails we were riding in the '90s, which we chose to ride because the trails suited the bikes.

In the case of Cathro and Minnaar, I think the pieces were in place to achieve nearly modern performance, and the limiting factor was the boldness and patience for riders and manufacturers to get far outside their comfort zones and test radically different bikes. There may have also been some differences in DH courses that didn't favour increased stability as clearly as current courses, but I don't think that's a sufficient explanation, as 2000s DH courses weren't any more slow and janky than modern enduro courses. Maybe a full-on modern DH bike would've been slightly overkill for the courses of the time, but modern enduro bikes aren't far off modern DH bikes.

I think the slow progress was due to evolving the design by 5 mm here and 0.5° there every 3- to 5-year product cycle. Almost no companies bracket with their design changes by going too far, then dialing it back to find the optimum. The development process usually involves making a change, observing that it's better, and just going with that, without exploring whether if some was good, maybe more would be better.

As a point of interest, I have a custom 2006 Iron Horse Sunday that was built for Sam Hill, but incorrectly made with the longer seat-tube (he ran a size Large front triangle with a Medium seat-tube). The head-tube angle is about 60.5° or 61° and the Large was unusually long for the time. The geometry is similar to the current Specialized Demo, with the smaller wheels and slacker head-tube angle creating a similar trail value. Everyone who rode it immediately knew it was different and I absolutely loved it. If I rode someone else's bike, I couldn't get off it fast enough! It was obvious that every off-the-shelf bike was simply wrong and the solution was as easy as changing the mitre angle, yet no one tried it. That said, it was a very different riding experience: the bike didn't feel like the right tool for the job until I was riding nearly at my limit, so maybe not every customer would've been into that.
  • 1 0
 @R-M-R: Increasing the trail on compression!
Like this?
www.pinkbike.com/photo/17994253
I know some of the reasons did not finish building up, but most just in my own head
But should dig it out & at least ride it !
  • 2 0
 @aljoburr: Always a fan of wild experiments!
  • 1 0
 @R-M-R: If only there was not such resistance to change, otherwise climate change would not be a problem!
Here is something of interest, did you know that hydrogen gas can be extracted using very low energy from sewage water?
Not my research, but very important all the same!
Wonder how long will take, before they stop dumping it in the Oceans?
www.youtube.com/watch?v=LaT5PZixcV0&t=2s
  • 1 0
 @R-M-R:Regarding the Shiver SC: This is accurate. WBP was .... interesting that year.
  • 9 0
 This is conceptually interesting...I just wish the linkage program supported linkage forks and not just rear suspension. Seeing how different designs like this interact with trail, wheelbase, and such is interesting.
  • 1 0
 @TrueScotsman: thanks! Never heard of that
  • 2 0
 @TrueScotsman: Tony Foale - one of the best MC Engineers, with a gift for making things clear to others.

He, Hossack, Fior, Valentino Ribi Saxxon, Leitner , Andre De Cortanze and a fair few others have made great "funny front ends". BMW, notably, have made use of at least 2 of said designers. Without, if I recall correctly, financial recompense.

A good thing to look up, for those not familiar, go looking for Ribi Quadrilateral Forks - multiple pictures are just a few 'clicks' away. Their progression, from his own start, notably tried and raced by Roger De Coster on his RN Suzukis, to the various Honda incarnations of it, is quite the thing. Honda bought the rights to it through DeCosters' insistence. It's an example of making a beautiful, but incredibly complicated - some variations with more than 20 pivot points - front end, to attach to a 'normal' steering head frame.

In strict Engineering terms, Telescopic Forks are quite the "Engineering Abomination".

But, bloody hell they can, and so many do, work well. In so many applications.

Many of the designers of Funny Front Ends (FFEs), have come out with "we need the riders brought up on Telescopic Forks to Die Out", due to how used we are to them. The best ( well, the most accepted) "Funny Front Ends", have been made to closely duplicate the actions / geometries / paths of Teles - that perhaps goes back to the FFE designers wanting the 'passing' of riders.......

The biggest mistake made with so many FFEs, is strictly adhering to The 'Perfect' Engineering and Design an FFE can give you. Resulting in truly strange / disconcerting performance, despite their 'correctness' of design. The multiplicity of bearings / pivot points ( and the precision needed for those multiples, and wear / 'play' they can / will have, Plus (moments of) Inertia of so many of the designs, can present problems to rival, or exceed, the inherent problems of Telescopic forks.

"Funny Front Ends" - I like Many of them. And, despise some of them. Done well, they can work well. Done badly, they can be dreadful. Just as "Engineering Abomination" telescopic forks can.

It will be interesting to see what PUSH eventually do have as a front end, to sell.
  • 1 0
 If everyone stopped buying current forks would happen quite quickly, more resistance to change!
I think Dave 'trust fork' though would be more interest, but turns out demands re-education & even all governments round the world working together are struggling to pull that one off?
  • 1 0
 @Bearorso: good synopsis.

It’s a shame that Pinkbike had an E13 Motion Ride fork in their hands for a demo and never got around to riding it; they had it for a while apparently
  • 6 0
 As a bicycle riding motorcycle guy turned full-time bicycle guy I realize there are some differences between bicycles and motorcycles. On the flip side, as much as I respect DW and DM, I have to do some head scratching as to why linkage forks will ultimately perform better for bicycles than they have in motorcycles, especially when the investment on the motorcycle side has been so much larger. I am 100% in for innovation and hope that if PUSH does release a fork it's every bit as awesome as their shocks and service.
  • 1 0
 I don't think the fork will be a linkage, this reads more like an attempt to hype up interest in a new Push fork by showing an old prototype. Nothing in the article makes me think the linkage fork is a predecessor to whatever they're coming out with. If I had to bet, Push's fork will end up being conventional-ish with maybe a dual crown or square tubes riding on needle bearings or some other tech aimed at reducing friction/stiction
  • 2 0
 @chize: Yes, just a way of keeping the name in peoples minds. Probably held up by supply chain issues and this would have been where they would have been thinking of launching it.
  • 6 0
 Interesting how all the linkage forks that fit on normal frames seem to have performance issues but I’ve yet to hear anything bad about the front suspension on the Structure Cycleworks bike, as reviewed here: m.pinkbike.com/news/review-six-months-on-structures-wild-looking-cycleworks-scw-1.html
  • 6 1
 I know I’ll get downvoted but really? Is this going to perform significantly better than a non linkage fork?
I followed the hype and tried an 11/6. Set it per their recommendation and it was ok, lots of cool knobs turn. But for the price and weight it needed to be better than ok. Sold it still running air Fox.
  • 8 1
 Shit like this is what I love about the bike industry. New ideas all the time.
  • 10 0
 Based on the Earle's Fork patent, used on BMW motorcycles from 1955 to 1969,
  • 2 0
 @englertracing: I had a Sachs 125 MX back in '69 that used this design also.
  • 5 0
 is Specialized buying the Trust fork patents like how Santa Cruz bought the Maverick patents? in that we will never see the technology again?
  • 8 3
 I hope so....
  • 1 1
 One can only hope
  • 1 0
 It's the Sony Music model for competition.
  • 5 1
 Interesting that Push offered to help develop the Trust damper. If Trust had accepted, might things have ended up differently for Trust?
  • 4 0
 I think the problem with the Trust forks was the wheel path (too rearward initially, too tightly curved), they were also regressive in terms of vertical wheel rate and flexy laterally. I also didn't like the shortening offset on corner entry, but that could be a personal preference.
  • 1 0
 They apparently didn’t Trust them enough.
  • 3 0
 Idk about you guys but that looks like a telescopic fork with a linkage added to it. Seems practical to engineer the fork starting from what already works and progress it in another direction though.
  • 6 0
 rip trust
  • 8 0
 Pretty sure selling your patent(s) to the biggest company in the industry is not consider a failure to most start-ups.

Always thought the Trust forks were cool and interesting, but at the end of the day paying more to add weight to my bike when the current traditional forks perform so incredibly well is just impossible to justify. If I were them I'd be very please to cash out on the patents and move on.
  • 1 0
 @ironxcross: If specialized is able to get it to work it will definitely bring more attention to this type of suspension than even a successful startup on their own that only sells shocks. The average biker who doesn't keep up with every bit of news probably hasn't even heard of a company like trust and likely never will. But if we see these forks on specialized bikes people will actually know about it and look into it.
  • 2 1
 This looks a million times better a Trust or Motion linkage fork, but if RMR has taught me anything, it’s that a good looking linkage fork almost definitely is not a good performing linkage fork. They perform their best when they look as unorthodox as possible.
  • 2 0
 If we base our impressions entirely on looks, we’ll never achieve a superior design.

Clearly we are all used to a straight “linear” look to our fork. Bike forks have been straight for years, but if we look at the evolution of rear suspension, there’s nothing straight except in a rigid frame.

Aesthetics guiding design is a terrible way to build a better mousetrap.

I just bought an E13+ Motion Ride fork. I had demoed one a few months back, bought a telescopic fork instead and have not been satisfied, so I ordered my own earlier this week.

Having extensive ride time on the Trust Message and Trust Shout, I’m a confirmed linkage fan, but like all things there are pros and cons.

I think it's kinda sad that aesthetics is a guiding principle, if anything, using aesthetics as a value has limited innovation, as a result most people ride a dated and inferior front suspension.

I’d love to see a Push linkage fork, but from a business standpoint it’s probably a bad idea ( see above comments).
  • 1 0
 It’s an interesting design. Depending on HA and lower lever length, it could create an essentially vertical axle path…lots of design freedom to dial in right response. Unlike USD designs that rely on massive cross sections for torsional rigidity, this uses the linkage to stiffen things up. Unlike the problematic thru shaft air spring crammed into the Trust forks, this design could use tried and true damping technology from traditional forks. For the child-like riders out there who factor in looks over performance, this design (if ever adopted) doesn’t look bad & would quickly look ‘normal’ as people saw them more.
  • 2 0
 I would like to see something similar to the old K2/Girvin linkage fork with a push shock on it.
keyassets.timeincuk.net/inspirewp/live/wp-content/uploads/sites/11/2018/10/hubmarket-3433-0-66710600-1357719263.jpg
  • 1 0
 There was an Australian guy who made his own DH bike called 'Minkie' back in the 1990s/2000s? and it had a long-travel fork similar to the Girvan. Used a standard rear shock. Linkages were much longer than the Girvan. Can't find a photo.
  • 1 0
 I think this could be really nice but not as a first model. You can build a regular inverted fork first, all CNC with a high end damper.... just do your thing. Then a couple years later you can build a version for "nerds" with the floating brake linkage.
  • 1 0
 Plain and simple, the design of today’s forks rock!! Majority of the damage incurred is on the lower body/sleeve and not on the stanchions. Why change a very expensive component that’s working in more ways then one, to keep you riding!?
  • 1 0
 Are you still riding your first mountain bike?
  • 4 0
 So, a telescopic linkage fork?
  • 5 0
 Inverted telescopic linkage fork
  • 5 0
 @vemegen: Inverted telescopic linkage dual-crown fork
  • 5 3
 Not another one, sheesh. Linkage forks of almost every configuration have been tried and abandoned in every form of two wheeled motor sports for a reason.
  • 2 0
 Nearly... Sidecar rigs commonly use linkage forks, but I'll admit they aren't at the peak of technology. BMW had used a telescopic fork with a linkage driven shock. The call it 'Telelever' and when I test ride one years ago it was incredible how little it dived under hard braking. It didn't modify the axle path, instead it modified the suspension kinematics to eliminate brake dive and still retain good suspension compliance. That would be interesting on a bike, but I believe it would require it being a system integrated suspension.
  • 2 0
 @BarryWalstead: they’ve abandoned it in their big roadster, said was packaging problems when they switched to radiators, but really they thought a traditional USD fork would sell better to young hipsters. It’s still going strong in their 1250GS, arguably one of the most popular and capable adventure bikes ever. I have an old roadster with it and love it. Definitely be a packaging problem on a mountain bike.
  • 3 0
 Is Push going to introduce a conventional fork or is this a taste of what's to come?
  • 2 0
 It’s not clear right? The article is all about why they didn’t proceed with the concept and then the sound-bite at the end reads very much like “review tomorrow”.
  • 2 0
 Might be worth while if whatever your doing requires less front brake dive and weight isn’t an issue.
Wouldn’t need for my riding style
Works well on my bmw motorcycle
  • 1 0
 Looks like a rehash of the " Preston Petty No-Dive" motorcycle fork attachment from the '70s. motocrossactionmag.com/forgotten-motocross-tech-how-to-make-a-faster-by-leveling-it-out
  • 2 2
 Why not leaf spring designs like the ones used by the homicidal South African runner? It all looks unwieldy and ripe for a rock or log to rip off the axle or catch on. I'm no engineer so what do I know...
  • 2 0
 @blcpdx: Kinda, but burlier. I only see Laufs on HTs and fatties...
  • 1 0
 motion was building something like that
  • 4 0
 @Staktup: yeah, I think a long travel leaf spring design requires a damping mechanism, like on a truck
i.pinimg.com/736x/dc/0d/cb/dc0dcbeb5047702d19898afb32f43c0d.jpg
that ends up looking like this:
www.motion-ride.com/en/16-125-motion-e-18.html?sld_id_country=8&SubmitCurrency=1&id_currency=1
Pretty wild stuff huh???
  • 2 0
 @blcpdx: Whoa, yeah- like that!
  • 2 0
 @blcpdx: Was that second link showing us something taken from the Cyberdyne Systems Model 101 squished in a hydraulic press a few years back?
  • 2 0
 LKOL
  • 1 0
 E13 Motion Ride:

I ride one, good fork, better than a Trust.
  • 1 1
 "USD forks are susceptible to lateral deflection, but the Earles concept helps to stiffen up the steering."

Those don't match up. Stiffening the steering would come mostly from torsional stiffness, not lateral stiffness.
  • 2 2
 Do motorcycles use linkage forks? There's over 100 years innovation by 100's of companies and as far as I know none of the best in their category use this design, that should tell us something.
  • 2 0
 dont remember his name, but BMW hired the enduro world champion to race one...he didn't make it through the season. quit and went to conventional forked bike.
  • 3 0
 BMW does, if you google "Duolever" or "Telelever" you can see non telescopic fork designs used in production motorcycles.
  • 1 0
 @trvrtnn: Telelever was a "conventional" fork with a pivot at the headtube. Rides like a dream on-road. I think they discontinued it because it was too expensive. Duolever on the other hand is some wild-ass linkage setup and i've never ridden one.
  • 4 0
 Joel Robert won a world championship on a Sachs 125 with a leading link fork.
classicavenue.com/product/1969-sachs-125cc
  • 1 0
 @WinoBot: BMW still use Telelever and Duolever. Telelever is on the 1200 boxer bikes (RT and GS), and Duolever is on the K1600.
  • 1 0
 @Joecx: a beauty! And so much cheaper than a new mountain bike…
  • 1 0
 @Joecx: Don't believe BS from a sales ad. Joel won 6 World 250cc Championships - 3 on CZs (1969 sure as hell was Not on a Sachs125 - it was on a CZ250) and 3 on Suzukis. The great man died this year, through complications brought on by Covid-19.
  • 2 0
 Looks fragile. Imagine a rock hitting one of the linkages...gonna cost fixing it.
  • 2 0
 Put it up against Structure Cycleworks front linkage suspension and do a comparison. They have the numbers to beat.
  • 2 0
 We're game.
  • 5 2
 Ugly…sorry
  • 1 0
 Full breakdown of the Trust Message..

bikeco.com/trust-message-fork-review-geometry
  • 2 0
 What we really want is to see it being hucked to flat
  • 1 0
 I'm glad there are others to think of suspension details. The more set and forget the better!
  • 1 0
 Is that choice of polished frame with a top tube mounted shock an homage to the Amp B2? Kudos if so!
  • 2 1
 they might work well but theres no getting away from the fact theyre bloody awful looking
  • 1 1
 I think the wheel has been invented with the current makeup of forks. Those contraptions are just a bust for more moving parts and weight but kuddos for trying.
  • 1 1
 We need more fork options, but no one wants a linkage fork, even it's better, most people can't tell anyway. Please make a fork without linkage.
  • 1 0
 They're just trying to corner the mud guard market with that mounting platform.
  • 1 0
 First time that fork gets ghost ridden into a rock field, it's gonna shatter like glass
  • 1 0
 I would like to 3 months toride test ride some of these new fork designs, then have an opinion.
  • 2 0
 I hope they Patented it to stop someone else making the same mistake.
  • 1 0
 Seems like it'd be easy to break with one sideswipe :/
  • 1 0
 Am I the only one worried about the rigidity at the axle?
  • 2 0
 Just dont crash
  • 1 0
 So the fork moves forward at max travel ?
  • 1 0
 "That's gonna be a no from dawg" -Randy Jackson
  • 2 2
 It is being dropped in motorcycle industry for a reason, i doubt mtb will adopt that
  • 4 1
 Out of interest, what's the reason?
  • 1 0
 @Woody25: my guess is to only reduce costs. performance be darned.
  • 1 0
 My dad has an old BMW R60 from the 50s with this type of fork
  • 1 0
 In the 4x4 world of suspension this looks like a built in sway bar.....
  • 2 2
 Forwards axle path? Is this a joke?
  • 5 0
 The more travel you use the longer your wheelbase becomes. What's the problem? Everyone wants lower, *longer* & slacker right?
  • 3 0
 Not forward, just less-rearward.

Ignoring the chain-driven antisquat and steering dynamics that come into play with MTB, it’s possible that the best suspension performance would come from perfectly vertical travel front and rear, more or less like a car. Then our wheelbases are remaining pretty much constant despite what either wheel is doing in terms of suspension.
  • 1 0
 @AckshunW:

You can maintain constant wheel base and have reward axle paths. The two aren't mutually exclusive.

A vertical axle path may be good for chassis dynamics, such as front end dive, but will perform worse when it comes to traction and comfort. This design makes sense for a motorized street bike, but not an off-road MTB.
  • 1 0
 @AckshunW: Are mutually exclusive*
  • 1 0
 @z-man:

True! But I missed mentioning in my statement the real crux of my argument —- more vertical paths would maintain wheelbase AND relative weight distribution.

Although to be fair, all model of MTB chassis dynamics under compression seem to be oversimplified and flawed - like the Trust idea of maintaining trail. During a square edge bump hard compression, your contact patch is probably way forward of normal, and during rebound way behind. How do flat-ground measurements of trail matter at that point?
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