Bicycle Rear Suspension by Specialized




Research & Words by Daniel Bacon //

Letter from the Editor

Our new Speculation column is a space for writers to share well-founded theories, concepts and speculations on the bike industry, athlete news and other interesting topics. While we may have inside industry knowledge to prove otherwise, we are happy to sit back and let the creative minds work on spinning up these theories and allowing readers to discuss and ponder. We are not saying what you’ll read below is fact or fiction, but we are definitely excited to be riding lots of new stuff that will be released in 2021. 

If you’d like to submit a story for our consideration please email with the title, SPECULATION. 

In this article, we’ll be discussing a new Bicycle Rear Suspension design patent filed by Specialized Bicycles, US patent 10,850,798. The publication date is Dec. 1st, 2020 and the filing date is March 28th, 2019. This patent is a continuation of granted application No. 15/941,686 filed on March 30th, 2018.

After my research, Wheelbased’s Speculation is that a new Specialized Demo suspension system and a new Demo E-bike are coming down the pipeline. For the sake of confusion and text, this system is also used on the new Enduro, but I’m just going to refer to the Demo throughout the article. I know the Demo has been released, but Specialized have a few designs they want to protect, including a Demo E-bike. The original patent from 2018 defines the design for the current Demo suspension system, so I’m not going to talk much about that one. This new patent explicitly attempts to define a slightly different suspension system, which should incorporate the E-bike suspension system.

For some background: the 2018 current Demo patent was rejected using both 9598140 and 5611557. Claim 1 wasn’t rejected, so the attorneys didn’t have to change anything substantial. If you look into those two patents, it’s easy to see that they’re not the same as this patent. In short, Specialized believe this is novel, the USPTO tried to reject it with a ‘motivation to combine’ rejection, it was successfully argued, and the patent was granted as novel in Aug. 10th, 2020.

As far as this new system and E-bike suspension patent go, this is also granted as of Aug. 6th, 2020. Again, the USPTO rejected this one with a ‘motivation to combine’ using two patents (9598140 and 6955373). The attorneys didn’t change much, but claim 1 was allowed, and now the patent has been granted. So for those of you that complain “SpEcIalIzed cAn’T dO tHat, sOmEoNe eLsE dId iT”, you’re wrong, and the USPTO says you’re wrong, too.

Bicycle Rear Suspension by Specialized


This system is only slightly different compared to the current Demo system, but the important part is that this design incorporates a motor. As far as suspension systems go, this new design is nearly identical to the current Demo except for one pivot change. On the current Demo, the bottom linkage pivot is concentric with both the chainstay and the bottom shock link. This reduces the amount of pivots and simplifies the design.

This patent takes that concentric pivot and breaks the pivot into two separate pivots. Figure 6C below shows the design. We’re looking at pivot 72a and 72e in this one.

Bicycle Rear Suspension by Specialized


Downhill bikes are incredible. I don’t think anyone can question that. I currently own a Commencal Clash and a Norco Aurum HSP. The Commencal is a very long travel trail bike and the Norco is a balls-out race bike. While the Commencal is incredible on the downhill, and has nearly as much travel as my Norco, there is no substitute for a modern downhill bike. They inspire extreme confidence and, in my case, are much more capable than I can actually make the bike perform.

Loic Bruni, Fin Isles, and Chris Grice are currently going fast as shit on the Demo. With Loic performing like a French surgeon and Finn racing like the UCI’s Ricky Bobby, there are times when I genuinely cannot believe how fast these people go on these bikes. Let’s not forget Chris is a 2-time Jr. US national champ. US downhill is looking bright and I’m hyped as fuck about it.

Similar to my last article about a Specialized patent, they are in the business of money and speed. They make bikes that win, and when they win, they sell. Win on Sunday, sell on Monday. It’s been like that since Gaius Appuleius Diocles was racing chariots 2000 years ago. Those were probably the hottest chariots, and everyone and their mother wanted one.

Right now, Specialized are building some of the hottest chariots on earth. With the massive amount of research and design that goes into them, why would they not protect their idea? This Demo is a culmination of efforts from a large group of people, dialing in a bike that is both fast on the track and accessible to people like you and me. The task of homologation is no small feat, and the designers, engineers, testers, and riders at Specialized, and every other brand for that matter, should be commended on their efforts.  Specialized aren’t building one-off race bikes that are entirely unobtainable to the broad market and I’m stoked that the same bikes that the big dogs ride are nearly identical to the ones we can ride on weekends. This is a key component to the appeal of biking.

On top of all of this, with the current push in E-bikes, and the production of smaller, lighter, and more powerful motors and batteries, the introduction of a full downhill bike with a motor must happen. There isn’t a board room in any manufacturer that isn’t having this conversation right now. As with most bike trends, Specialized may be one of the early adopters in this trend.


With around 200mm (or 8ish inches for the freedom lovers) of front and rear squish, downhill bikes are monster truck-style mountain bikes that can go through or over just about anything. The prior Demo was released around 2015/2016 and this latest Demo was introduced in 2019/2020.

The new demo incorporates a 4-bar suspension design with 6 links, so it’s a linkage driven 4-bar system similar to the Canyon Sender. In fact, Specialized reference the Canyon Sender in their application in the ‘other publications’ section. Specialized note the similarity but still go ahead with this patent because they obviously believe it’s a different design.

Additionally, this bike may remind you of the Banshee Legend. Both bikes are similar, but Specialized have designed a bike that functions fundamentally differently.

The first part of this video has a good explanation of how the current Demo system works. Remember that the suspension design in this article is not exactly the same as the one in the video.


For the sake of not writing 5 pages on the current design, there is not one single piece that is novel here. Rather, the entire system appears to be novel. The use of multiple links to incorporate a 4-bar linkage system, using two links, an upper link and the bottom link, which are concentric around the rear shock pivot, and with the additional use of a concentric pivot incorporating a lower shock link and the chainstay attached that is attached to the front triangle, appears to be novel. That was a mouthful.

This patent is another example of the new Demo 6-link suspension system. In the case of this particular new patent, the intended novelty is to separate the bottom pivot into two different pivots, where the lower shock link pivot is forward of the upper member pivot attached to the front triangle. The forward part is important as this appears to be a critical part of the design. This is important enough to put in claim 1, meaning it’s necessary to protect.

So how does this relate to the E-bike? The design of the new E-bike may fall under the same design/claim scope, though the pivot configuration is slightly different than the one in Figure 6C. It’s possible we’ll see another explicit patent on the E-bike design.

Additionally, as far industry novelty goes, I don’t believe a full downhill bike with a motor has been mass produced by any of the big manufacturers, yet. Some smaller manufacturers have released something, but not with the manufacturing power that Specialized have. It’s important to note that Bike + Motor is not equal to novelty. Specialized don’t claim that part is novel, they claim the suspension design in the E-bike is novel.


Referring to the non E-bike with this new design, Specialized don’t state any explicit advantages or disadvantages. But, as far as the E-bike goes, Specialized states some advantages to this design:

Moving the pivot axis 72a rearward may, for example, help to provide more desirable suspension characteristics with a heavier bottom bracket area of the frame. In this embodiment, the crank axis Ac is also positioned horizontally between the pivot axes 72a and 72e, which may, for example, help to provide more desirable suspension characteristics with a heavier bottom bracket area of the frame. In other embodiments, the crank axis Ac may be positioned in line with or behind pivot axis 72a.

So, Specialized think this design may help with a heavier bike. In particular, it may help with a bike with a heavy bottom bracket. As a side note, it’s very interesting seeing the companies patenting things that would have been unthinkable 10 years ago, like this one. This patent incorporates a specific mechanical bike suspension and a specific E-bike suspension. Both are independently designed and manufactured.


Specialized have designed a 4-bar suspension system with 6 links. Figure 3 shows the linkages to drive the shock through the bike’s travel. As the bike goes through it’s travel, both links 74 and 84 rotate clockwise, compressing the shock. It’s a funny looking design, but the current World Cup results show that it doesn’t need to look good to work well.

Bicycle Rear Suspension by Specialized

Figure 2 and 6C show the current Demo configuration and the new design configuration, respectively. Notice how the bottom pivot is split into two separate pivots and the lower shock link pivot is in front of the upper link member pivot. Additionally, the pivot 72e being used by the bottom shock link 84 must be in forward of the upper link member pivot 72b, shown in Fig. 6C below.

Specialized state:

FIG. 6C illustrates an assembly similar to the embodiment illustrated in FIG. 2, except for the first end 84a of the lower shock link 84 being pivotally coupled to the bottom bracket support member 56 at pivot axis 72e instead of pivot axis 72a.

Bicycle Rear Suspension by Specialized

So, as stated before, the single pivot is being split into two pivots. Figure 6C shows the important part, where the pivot 72e is forward of the upper link member pivot 72b. Note that Figure 6C has a piece of the chainstay missing, so the artist’s can show link 84. In reality, chainstay 70 will link up with pivot 72a.

Now we’ll talk about the E-bike. As shown in figure 7, the [chainstay 70] pivot 72a and [bottom shock link 84] pivot 72e are still separated, but pivot 72a is moved much further back. This may still work in the scope of this invention and the claims in this patent may cover both of these designs. Specialized state an ideal scenario for the E-bike design as:

…a horizontal distance between the lower arm pivot axis 72a and lever arm pivot axis 72b is desirably at least twice a horizontal distance between the lever arm pivot axis 72b and the lower shock 45 link pivot axis 72e. In some embodiments, it can be desirable for this ratio to be at least or approximately 3.0, 2.5, 2.0, 1.5, or 1.0.

Bicycle Rear Suspension by Specialized

Additionally, Specialized state another small change:

Another difference in the bicycle frame 712 of FIG. 7 is that the bracket 57 of the downtube 54 extends further 50 rearward of the main body portion of the downtube 54.

In other words, Specialized want the forward shock pivot to be behind the down tube, not in the downtube.

Specialized show a few more interesting configurations in this patent that may or may not be patented already. Figure 6A shows a very similar configuration compared to the current Demo, but the forward end of the shock pivots around the same pivot as the upper link member 74. Specialized don’t state any explicit advantages, but they do say:

…figure 6A desirable no longer includes the bracket 57 or gusset 58 because the shock absorber 26 is no longer pivotally coupled to the down tube 54.

I think we can all read through the lines on this one to see why they might want a configuration like this.

Bicycle Rear Suspension by Specialized

Figure 6B shows another similar configuration to the current Demo design, but the upper shock link 82 is now connected to the upper link member 74 with a separate pivot and is not concentric to pivot 72c. Again, Specialized don’t state an explicit advantage, but they do open up the design possibilities, stating that pivot 72e can either be on link 74 or seat stay 76.

Bicycle Rear Suspension by Specialized

Lastly, figure 6D shows the same configuration as the current Demo, but with a shock extension 31 attached to the rear of the shock. Specialized state this design has a few advantages:

Using a shock extension 31 can have various benefits, such as changing the shock leverage ratio, avoiding interference with the rear wheel or seat post, and/or the like.

Bicycle Rear Suspension by Specialized


I’ll be honest, I haven’t been a proponent of E-bikes for the broad market. Some love them, some hate them, but there’s no denying this is where the market is going. I almost liken it to the snowboarder/skier battles from the 90’s. I think they’re amazing pieces of machinery in certain situations and the situation that Specialized are presenting in this patent is incredibly enticing. Currently, Husqvarna are making an E-DH bike, to the tune of $7000 USD for the entry level, for those that want to crush weekday laps at places like Windrock. No shuttle = no problem.

But for those that are reluctant to understand the reasoning held by the non-E-bikers, I can offer some situations that should be pondered. Would any of you mind seeing full 200mm downhill bikes on their local trails doing lap after lap? For the actual trail builders and maintenance folk, do you think something like this is good or bad for your work? Do 200mm downhill bikes need to be on the same trails as hikers and dog walkers, or are they one-in-the-same with 170mm trail bikes?

For those that are reluctant to understand the reasoning held by the E-bikers, I can also offer other situations that should be pondered. Why would you not want to make your life easier? Do E-bikes deviate from the scope of a purely mechanical bike? What’s the difference between a shuttle/lift and an E-bike?

In the end, Specialized have only slightly adjusted their long travel bike suspension. In this case, the suspension can now be incorporated into an E-bike more effectively. It’ll be very interesting to see what the final product may be.

And whatever camp you’re in (E-bike love or hate), I hope you enjoyed this article. Thanks for learning some shit today.

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