Exclusive! Chris Currie’s all-new full suspension design is unlike anything you’ve ever seen

Chris Currie mountain bike suspension patent drawings

Editor’s Note: Chris Currie has been in the industry for years, many of which he’s spent quietly designing, patenting and slowly but surely developing his own full suspension platform. In this new series, he’ll give us a peek inside the process of creating something new, the myriad ways to bring it to market and the challenges of it all. Without further ado, here’s Chris:

Eighteen years ago, I started an online bike shop called Speedgoat out of an old one-room schoolhouse in the mountains of Southwestern PA. I didn’t have “start-up capital,” a background in web development, or a business degree. All I really had was an obsession with bikes and a wife who was just crazy enough to go along with me. For fourteen years we worked with the best companies in the bike business, building up thousands of custom bikes for riders around the world. We knew the names of our customers’ dogs, even if the customers lived thousands of miles away. It was that kind of business.

In 2010 I sold the company to people I thought could take it to the next level, but they were a trainwreck. Frustrated with the new owners, I left in 2011. In the years since, I moved west to manage sales, marketing, and customer service for Velotech in Portland, Oregon, while moonlighting for Stan’s NoTubes, where I’m now Creative Director. Through it all, one personal project that started at Speedgoat ten years ago has stayed with me. I had an idea for a bike.

Since 2004, I’ve been quietly developing an entirely new suspension platform. The original idea started innocently enough, but got out of control pretty quickly. I ended up teaching myself Solidworks to be able to draw and dimension what I was trying to visualize in my head. I applied for a patent in 2007 when the numbers started telling me this could be something special, and was granted a patent for the design in 2010. Until you have a rolling prototype, you have nothing, so I didn’t make a big deal about any of this, but somehow the design started to earn a bit of an underground following among engineers and product managers. In 2011, I was in such a low place after leaving Speedgoat that I started writing about the design on a blog I’d started. A few early drawings made their way around the interwebs, and I started to hear from people in the industry. They were getting it. They could see what I was trying to do, and there were a lot of questions about licensing and what I was going to do next, some from people I respected very much. One day I sat down, re-read my own patent online, and started opening files I hadn’t touched since the whole company sale debacle. I had no idea how to make a proof-of-concept bike, but I knew that’s what I had to do.

Today I have six of those bikes sitting in my garage (my wife is still extremely understanding). The current prototype has 160mm of rear travel (6.3″) and is built on 27.5″ wheels. It has a 66º head tube angle when used with a 160mm travel fork, but it’s designed around a straight 1.5″ head tube, so it accepts AngleSets and Works headsets with tapered forks, making the full HT angle range 64-68º. Seat tube angle is 74º. Axle path is one of the special things about the design, and it lets me keep the chainstays to 429mm (16.9″) with plenty of clearance for 2.4″ tires.

The bottom bracket height is adjustable with a chip system built into the lower shock mount, and the frame uses an 73mm English bottom bracket. I had an idea for a PF30 system that wouldn’t creak, but at some point it just didn’t make sense to deny the superiority of good ol’ English threaded bottom brackets (the worst part was admitting my friend, Jason, had been right from the start).

Dropouts are set for 142mm spacing but are modular, because there are no standards any more. Prepare to be boosted. The frame has a removable ISCG tab and can accommodate a front derailleur, if you really want to do something like that.

The current bike is really just a test bed for suspension technology, though. That’s my patent, and that’s what stands out to anyone who rides the bike. Back in 2005, I made an absurd wish list of performance criteria that included obvious things like chainstay length and axle path, but also more esoteric details about pivot point locations for manufacturing precision, leverage ratio adjustability, and shock placement (wasn’t allowed to mount in the center of the downtube, because I’m convinced that leads to really heavy, reinforced downtubes). I ended up designing the suspension to work with just about any shock orientation, though.

 

I have about 100 separate drawings of the kinematics like this in Solidworks.  It looks stick-figure, but the lines can be rotated through the bike's suspension movement and precisely measured. Then there are all the 3D parts drawings of the shapes that fit into place.

I have about 100 separate drawings of the kinematics like this in Solidworks. It looks stick-figure, but the lines can be rotated through the bike’s suspension movement and precisely measured. Then there are all the 3D parts drawings of the shapes that fit into place.

But one performance criteria set the tone for the whole system: The bike wasn’t allowed to bob at all on the climbs, even in a shock’s ‘descend’ mode. I mean no tiny pulse at the rocker, no subtle cable movement: zero. If you were under power, only bumps could make the suspension work. But -and this was the stupid “cake and eat it, too” part- you also had to be able to compress the suspension just by standing beside the bike and pressing down with one hand. I’ve ridden a lot of bikes that pedal great, but go jackhammer on you when you really need them to work. I’ve also ridden a lot of bikes that just don’t pedal well. Based on what I was seeing with instant center behavior and axle path on the computer, I thought this design had the potential to balance pedaling and suspension in a very different way. And it does.

I don’t come from an engineering background, but being stupid’s never stopped me before. I wasn’t a web developer when I created one of the first online custom bike configurators at Speedgoat, either. I’d be the first to say I have “fixation issues.” I have this natural gift for making my life completely unbearable. There’s probably a gene that keeps people from obsessing about ideas until they’ve stopped sleeping and wrecked their health. I don’t think I have that gene.

Here are the front triangle drawings built up from the original kinematics. This is the Large frame size.

Here are the front triangle drawings built up from the original kinematics. This is the Large frame size.

Back in 2005, the original business part of the idea was much simpler: develop a less expensive private-label bike as a compliment to Speedgoat’s high-end brands. The sensible thing to do would’ve been to pick up an open mold hardtail from Taiwan or China -just point to a picture in a catalog and move on to thinking about paint jobs- but I went down the rabbit hole. I’d been around to see some of the first suspension systems used on bicycles, and I’d spent so much time building and riding great bikes from Santa Cruz, Titus (and later Pivot), Niner, Intense, you name it, that I just couldn’t stop thinking about suspension systems. I’d work a fourteen-hour day at Speedgoat, then doodle pivot locations on pieces of scrap paper until the small hours of the morning. I started to see what really went into these designs, thought processes of brilliant guys like Joe Graney, Chris Cocalis, Dave Weagle, the ingenious ways Steve Domahidy and Chris Sugai were dealing with bottom-bracket drop issues on 29ers. One of the best things about trying to design something new was learning to really see what was already in front of me, the intent in other people’s designs. That’s when the insane wish list started.

In 2012, I started working with fabrication places both in the U.S. and Taiwan to create the current test mules. I worked with an engineer at Zen in Portland to make sure I had usable drawings and was accounting for all the components out there. After all, it’s nice to have cranksets that rotate and other basics. I hoped to keep fabrication in the U.S. because I thought that made more sense for prototypes, but Zen was really swamped, and no one had the time to take on the project, or even really estimate how many months it would be before they could. I ended up having to go to Taiwan, where I could get an estimated completion date.

Having a bicycle frame made in Taiwan is exactly like everyone thinks, and nothing at all like everyone thinks. The level of complication and overall expense actually went up in Taiwan -they’re not really into CNC machining one to two units- and communication becomes its own world with its own set of challenges. The problem with developing a product in Taiwan isn’t that they won’t build what you want; it’s that they will. Any detail you’ve missed, any problems with your design, get amplified and duplicated if you aren’t paying attention. I’ve invested in tooling and production for a dozen frames at this point. Any small detail that wasn’t caught and fixed with the first prototypes would now be wrong with those frames and the tooling needed to make them. Learning that process was both scary and amazing. If not for a key quality control guy over there, the whole thing would have been nearly impossible. It still seems impossible, but the first pre-production bikes are here and just about ready to meet the press and get test rides. At least one bike will be at Sea Otter.

The white frame here was  from the original prototypes and the silver frame is the current pre-production model.

The white frame here was from the original prototypes and the silver frame is the current pre-production model.

What happens now?

I don’t know. I wanted to make a great bike, something different from everything that’s been done before. I think I might have actually pulled that off, but I’m still prepared for the whole project to just come to a stop. Then I guess I’m supposed to realize I’ve wasted too much time and money chasing this, except I’d do it all over again. Given the increasing level of interest in the system, it’s also possible the design won’t have been a waste of time. I went to Interbike and rode as many new bikes as I could this year, thinking I’d realize my bike wasn’t that special and I could come home and pull the plug on all this, but nothing I rode pedaled as well, and even some of the terrible pedaling bikes didn’t handle small bumps nearly as well. I’d never ridden some of the big brands before, and I was a little shocked at how bad some of them were. There’s definitely a reason lockouts are still around. It’s probably impossible to be objective when you’ve put this much of yourself into an idea, but I tend to be pretty critical of myself -the last five years alone were spent just refining the design until I was happy with even some pretty minor details- and there does seem to be something really good going on with this design. Every time I’m about to quit, knowing there’s something potentially great here pushes me one step further.

To figure out where this goes, I’ve once again taken over the Speedgoat.com domain name and am relaunching Speedgoat as a design shop for the new suspension system, and possibly as a small bike brand. I got burned pretty bad by the people who took over my company, but I fought to get the domain name back. There’s a good bit of interest in licensing the design right now, and Speedgoat.com will be where I offer information about the system. Beyond that, my current ‘market research plan’ is to show people the bike, let as many people ride it as possible, and see if anyone wants one. That plan’s probably not going to win any marketing awards, but I have to focus on my day job, and I don’t see any reason to bullshit people. I’ve made something I think works really well, but my means are limited, so it won’t be carbon fiber or have color-changing paint or anything. I’d like to get some feedback from people, keep refining, and see what happens. That all starts at Sea Otter.

But, we’re getting ahead of ourselves. In future posts, I’ll discuss what it takes to create and patent a new design, what I’ve learned along the way, why anyone would be crazy enough to try to do this, and where the project seems to be going. If you’ve ever been curious about developing your own bike or patenting a design, I’ll be happy to answer as many questions as I can in follow up articles. I don’t claim to be an expert at this, but I’m happy to share anything I know, and help anyone interested in doing your own thing. The press will finally get a good look at the bikes this Thursday at Sea Otter, but if you’re curious to find out more about the bike, you can sign up for news at Speedgoat.com. A little under two thousand people are already on the list, and I promised to share news and photos of the bike with them first.

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Jaded Industry Type
Jaded Industry Type
7 years ago

So it’s got a front tri, a rear tri, a shock, and lofty claims about suspension performance. How is this different from EVERYTHING I’ve seen before? Guess I’ll have to wait and see…?

gsmith
gsmith
7 years ago

Ok, so how exactly does the linkage work and what’s so special about it? What’s the axle path like? None of the drawings clearly show what is going on.

Andrew
Andrew
7 years ago

Great read. I love that this industry still has grass roots innovation. Best of luck.

Jerry
Jerry
7 years ago

I remember Chris and even though I’m from Canada I did stop in and bought a Titus frame from him. Supercool shop, and I hope things work out for him. I used to love playing with his custom bike builder. Speedgoat is a great name for a bike company, good luck.

JB
JB
7 years ago

@gsmith: My strong suspicion is that the lack of clarity is intentional; I’m guessing he’ll spill the beans at Sea Otter and via the Speedgoat site.

@Andrew: totally agree: I really enjoyed reading this, and it brings me no small measure of joy to know that there are still people out there who are committed/focused/intent/stubborn enough to do something like this.

I, for one, am certainly intrigued: the design may be amazing, it may not be amazing, but I’m betting it’ll be thought-provoking either way. I’m looking forward to seeing photos and an explanation of the design- and to riding a demo bike!

David
David
7 years ago

High-forward linkage-activated single pivot, unless the lower pivot is only attached to the rocker, in which case chain tension provides anti-bob but there’s a rearward axle path???? Definitely looking forward to seeing how this plays out!

I bought my wife a Titus Racer-X from Speedgoat way back in the day. Speedgoat was always a great shop to deal with, despite my location north of the 49th. Good luck Chris!

out for a ride
out for a ride
7 years ago

Is there a tl;dr on this clickbait title?

Major Glory
Major Glory
7 years ago

Sounds cool to me. Hopefully Chris can keep production in the US.

gsmith
gsmith
7 years ago

@out for a ride

Nope! lol. It can’t be that great, there’s not a lot you can do to make suspension better that hasn’t already been widely done. We can already create whatever axle path is desired (using various VPP, FSR, etc etc type layouts). Feedback through the chain limits the use of extremely radical rearward axle paths while using an idler pulley (as seen on a few recent DH bikes) is going to decrease drivetrain efficiency (and add weight).

Jeff
Jeff
7 years ago

Chris is a good guy. I wish him all the success in the world.

pk
pk
7 years ago

I think I figured out whats going on. Its a pretty genius solution. If I’m right it’s a new take on vpp but with a better axle path.

Josh
Josh
7 years ago

Bought a Santa Cruz Blur first gen from Speedgoat and picked it up in person. That shop was awesome, I remember it fondly and whenever I pass through western PA I wish I could stop there. When I bought the Blur it was one of the first production runs and I had to wait 6 months for it from Santa Cruz. Chris very patiently kept me updated via e-mail on it’s status and the build was great. I still have that bike and even though it’s a “lowly” 26 incher, it’s still great fun.

Reg Braithwaite
7 years ago

“Dropouts are set for 142mm spacing but are modular, because there are no standards any more. Prepare to be boosted.”

So true.

Another Jeff
Another Jeff
7 years ago

Lot more pictures/info on the patent, http://www.google.com/patents/US7815207

dullknives
dullknives
7 years ago

you can always go view the patent online if you want to know more before sea otter. https://www.google.com/patents/US7815207

Carlos
7 years ago

The idea is very interesting, the concepts are clear and a man with the right attitude, check!

i’m going to follow the project very close.
Best of luck in Sea Otter.

Shawn
7 years ago

Go Chris !!

MissedThePoint
MissedThePoint
7 years ago

Looks kind of like Redline’s design.

Ripnshread
Ripnshread
7 years ago

Looks like a 4/6? bar with a lower linkage that rotates in the 1-4 oclock positions in front of the bb? The double mount looks like one for a linkage and one for a shock mount? Wish ya well Chris. Looks sweet. Can’t wait.

Jason
7 years ago

Here is Chris’s patent https://www.google.com/patents/US7815207

internet stoke
internet stoke
7 years ago

hell yea chris!! glad to see this a reality. ship one to denver!!!

COLIN
COLIN
7 years ago

I can totally see how this works, only question is… will my Di2 battery power the flux capacitor?

Heffe
Heffe
7 years ago

Great news. I always loved SpeedGoat and was sad to see what happened to it.

Muther
Muther
7 years ago

Knowing what i know about mechanical engineering, I still have yet to see anything even close to what my engineering mind would call the ultimate bicycle suspension. If true, this could be a remarkable bike. Rear-ward axle path, with chain stays that don’t telescope. Very nice.

The same chain stay length through out the travel would seem to me to neutralize much of the effects of the chain. I wonder about braking, though. It will be interesting to see what comes of this.

Tom
Tom
7 years ago

Rock on, Chris. Looks interesting, and gotta always root for the little guy!

Ascar Larkinyar
Ascar Larkinyar
7 years ago

the dumb down explanation is it’s a double moto-link suspension. even dumber version, four link design.

the bottom link travels rearward and lengthens the chainstay and chain while the upper link travels in a normal suspension capacity.

there are going to be drawbacks to this idea. unstable at speed and in tight fast turns do to bike length getting longer/shorter. undue tension on chain and shortened chain life with possible failure along with non-engineered pressure on fragile drivetrain.

pedal bob still needs to be controlled by shock(pedal platform or brain).

i am sure i can come up with more speculation, but to be fair lets just wait till this comes out. i applaud anybody who comes up with a new idea.

Sam
Sam
7 years ago

Seems similar to the yeti sb66.

fast foreward freddy
fast foreward freddy
7 years ago

This is just another dual link ala dw-link, vpp, maestro, switch link. the real magic in this suspension design is the legal juditsu that allows another company to make bike with a dual link without stepping on the others patents. It will work great just as the other dual link designs, but in no way is it revolutionary.
Same chain stay length as the hd3 btw.

PowersUSA
PowersUSA
7 years ago

Kudos for pursing your dreams. I wish I had the confidence in my own design to commit the necessary time and expense to take it as far as you have.

zombinate
zombinate
7 years ago

looks like DirtRag got the first ride. They show the linkage movement, I still don’t get how it does what he says it does, but I am not an engineer.

http://dirtragmag.com/exclusive-dirt-rag-test-rides-new-prototype-from-chris-currie-and-speedgoat-cycles/

chasejj
chasejj
7 years ago

Modified DW link. The lower link placement might allow a slightly shorter chainstay.
Kinematics probably are slightly different.

I totally get Chris’s obsession. I use to do the same (I am an ME). But conversations with other patent holders in the industry led me to sticking with my day job. Getting and defending a patent is a very expensive endeavor that can leave you bitter and exhausted.

The problem is there is always a rocket scientist like Weagle who is sitting back and issuing some mind blowing thing a month after you just made 5 prototypes.

Ol' Shel'
Ol' Shel'
7 years ago

For those who may not know, it would be natural for a rear suspension to squat as you accelerate, because a bike/rider combo has an extremely high center of gravity. Earlier, low-pivot designs did squat each time you stomped on the pedal because of this. They weren’t inefficient, but they felt like they were robbing your power.

To make riders FEEL better, chain-induced anti-squat was designed in. Some of your leg power is used to counter this natural squat under acceleration, by trying to extend the suspension in approximately the same amount that it’s wanting to squat. As riders, we care far more about the impression of efficiency than actual efficiency.

People are obsessed with suspension that resists initial motion because the media has told them to want that. Most people would be much better off with a system that is active and actually absorbs small bumps.

Bill Davis
Bill Davis
7 years ago

I wish Chris all the best. First, he’s gonna have to get people on this design, whether it be from a demo tour or other means, but I can’t imagine many people preordering and paying for a radically new frame upfront through crowd sourcing. I’m sure this frame will be in the $2500 plus range, probably higher. He’s always been obsessed with punching above his weight, so lets see how his rig compares to the titans within the industry who have millions to spend in R&D. We all might be surprised.

Pete
Pete
7 years ago
Padrote
Padrote
7 years ago

that the suspension should not activate at all during pedaling is a bad defining criterion. for a multitude of reasons.

D-unit
D-unit
7 years ago

It’s basically Switch Link stuff like found on the SB-66. Slight difference in link length, but same configuration.

Joe
Joe
7 years ago

As someone just starting to think about how to produce and market my idea in the bike industry, this post was fascinating. I’m really looking forward to the future posts because currently I have no idea what to do.

Jose
Jose
7 years ago

Suspension design today are many and can be called at this point in time a dime a dozen. Execution as was mentioned here is the issue.

Jose
Jose
7 years ago

To say there are no standards anymore is wrong. There are standards that any builder can use. There are more of them now. So what??? Just pick what are the better standards and use them. There are way fewer standards on bicycles than anything else. So I say to those who whine about standards, get some perspective.

Vance
Vance
7 years ago

Build it, I will ride it………

satisFACTORYrider
satisFACTORYrider
7 years ago

best of luck with it. props for goin for it

greg
greg
7 years ago

It appears that the main difference between this and most dual-link DW systems and their imitators is that this one’s links lead from the main frame to the rear triangle. The rear triangle connects to the links’ FRONT pivot and the front triangle is attached to the links’ REAR pivot.
interesting. Analysis will determine if it makes a functional difference from what’s already out there.

craigsj
craigsj
7 years ago

“…They weren’t inefficient, but they felt like they were robbing your power.
To make riders FEEL better, chain-induced anti-squat was designed in. Some of your leg power is used to counter this natural squat under acceleration, by trying to extend the suspension in approximately the same amount that it’s wanting to squat. As riders, we care far more about the impression of efficiency than actual efficiency.
People are obsessed with suspension that resists initial motion because the media has told them to want that. Most people would be much better off with a system that is active and actually absorbs small bumps.”

All of this is completely wrong. Pedal bob IS inefficient because energy from your legs goes into activating the shock (which is designed to dissipate energy). Designing in Anti-squat, on the other hand, does NOT use leg power to counteract the bob, the motion simply doesn’t exist in the first place. Lastly, a bike that bobs when you pedal is not “more active”, in fact they are typically less active because they have more oppressive low speed damping.

(deleted)

Mr Mojo Rising
Mr Mojo Rising
7 years ago

Chris, according to Don Belt’s linked in page, Speedgoat is his personal webpage. You better have a talk with that old man.

LaurelHighlander
LaurelHighlander
7 years ago

The above is an interesting revision of history, from a guy who was always looking to “go to the next level.” Enough time has past that we will all either forget, move on, or fail to care about the actual downfall of Speedgoat and the business that the Currie’s ran into the ground:

2 year prior to “selling the company to people I thought could take it to the next level” the death march started as they hired a Pittsburgh “executive” with no cycling experience to lead “sales growth” as the chief operating officer. Where is Don Belt now?

http://reviews.mtbr.com/don-belt-joins-speedgoat-bicycles-inc-as-chief-operating-officer

Best of luck, again. I enjoy your revision of history and wish you well. Poor poor Speedgoat, back from the grave that you dug and sold. Maybe Ben Serotta would like to go in 50/50?

PowersUSA
PowersUSA
7 years ago

I love it when all the Monday morning arm chair engineers come out when a “new” design is presented. I’ll spare you my analysis.

Frank "The Tank"
Frank "The Tank"
7 years ago

Well I’m certainly interested. The design appears to be sound and the movement makes sense. I’ve been looking at the pros/cons for different frame designs the last few years as it’s getting time to replace my current FS rig and this layout certainly fits my needs. I’ll certainly be watching this closer as things develop, I just hope I don’t have to buy something else in the meantime as I’d like to swing a leg over this and see how she flies. Final geometry will be a big determining factor though, as I’ve found a lot of things “work”, but few feel right, and this looks like it’s in the “feels right” bracket to me.

John Benham
John Benham
7 years ago

Hmmm, actually, many armchair engineer designs might be pretty sweet if they devoted the time and energy like Chris has. Kudos to Chris for pursuing. The fact is there are a ton of great bikes on the market. To say his design bike rides better than any at Interbike is a bold and confident statement. Again, kudos to Chris.