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Companies have achieved any axle path and shock rate you can imagine with much simpler 4 bar designs.
The thing is, you can't. Even if you could get the "optimum" wheel path, it would come at great compromise to some other desired quality, for example, pedal feedback through excessive chain growth. Every single parameter that a designer chooses is a compromise. Do I want a better climber or descender? Pedaler or bump performance. And it's always much more complicated than that.

The Missing Link helps bridge those compromises. A better pedaler AND better bump performance. A better climber AND a better descender. The Missing Link adds performance that is not possible with any other design or linkage.
 

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orthonormal
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I was just thinking that this design reminded me in some ways of Kona's old Magic Link and noticed on the website that Tantrum's founder/designer also designed that suspension. The new design certainly looks more robust.

I'd like to try one when they become available. My one personal nitpick based on geo numbers is TT length/reach. Would be nice if you added ~15 mm to each size. Also, I think you may find many people are looking for a slightly shorter CS these days. 5-7 mm shorter there could help you sell more frames.
 

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Companies have achieved any axle path and shock rate you can imagine with much simpler 4 bar designs.
This design isn't about axle path. What's unique here is that chain force pulls the chainstays forward, rotating the lower link, in turn extending the shock. I've never seen anything like it.
 

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I was just thinking that this design reminded me in some ways of Kona's old Magic Link and noticed on the website that Tantrum's founder/designer also designed that suspension. The new design certainly looks more robust.

I'd like to try one when they become available. My one personal nitpick based on geo numbers is TT length/reach. Would be nice if you added ~15 mm to each size. Also, I think you may find many people are looking for a slightly shorter CS these days. 5-7 mm shorter there could help you sell more frames.
Hi Andy, yes, the Missing Link is a continuation of thinking on what I was doing with the Magic Link. I figured out how to communicate the chainstay input into the upper end of the shock. On the Magic Link, it was through the lower end, with the small auxiliary shock as the main component being manipulated by the force.

With the Missing Link, I was able to remove the auxiliary shock, making it lighter, stiffer, easier to make and easier to setup. Not necessarily easier to grasp all that is going on, but I think, less visually intimidating and cumbersome. The Magic Link still has an advantage in pure bump eating, due to the ability of the main and auxiliary spring to work in series, offering an incredibly plush bump response. It also was aided in this regard by the variable axle path, which could have a more rearward trajectory on a square edge hit. For the reasons, don't be surprised to see a Magic Link DH bike in Tantrum's lineup.

The Missing link is better at pedaling and climbing, due to the ability to completely lockout the shock and go to full extension under max power, which also gives it more geometry change than the Magic Link.

Regarding geometry, we are always watching trends and tweaking things. The final geometry may be slightly different, but those are the numbers of the current samples, and they sure are fun. My personal opinion is that we may be reaching a plateau of diminishing returns on those trends, as some negative comments are starting to crop up in bike tests about ultra short CS and ultra long TT. But we will always make sure we are aware of test a variety of geometries to be sure we are not missing out on an advantage. For example, I have found I can use a much slacker HT angle than anticipated, due to the geometry changing effect that makes it climb about 4 degrees steeper. My Meltdown Race for the Sea Otter Enduro had a 64 degree HT angle, and still climbed great.
 

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orthonormal
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Hi Andy, yes, the Missing Link is a continuation of thinking on what I was doing with the Magic Link. I figured out how to communicate the chainstay input into the upper end of the shock. On the Magic Link, it was through the lower end, with the small auxiliary shock as the main component being manipulated by the force.

With the Missing Link, I was able to remove the auxiliary shock, making it lighter, stiffer, easier to make and easier to setup. Not necessarily easier to grasp all that is going on, but I think, less visually intimidating and cumbersome. The Magic Link still has an advantage in pure bump eating, due to the ability of the main and auxiliary spring to work in series, offering an incredibly plush bump response. It also was aided in this regard by the variable axle path, which could have a more rearward trajectory on a square edge hit. For the reasons, don't be surprised to see a Magic Link DH bike in Tantrum's lineup.

The Missing link is better at pedaling and climbing, due to the ability to completely lockout the shock and go to full extension under max power, which also gives it more geometry change than the Magic Link.

Regarding geometry, we are always watching trends and tweaking things. The final geometry may be slightly different, but those are the numbers of the current samples, and they sure are fun. My personal opinion is that we may be reaching a plateau of diminishing returns on those trends, as some negative comments are starting to crop up in bike tests about ultra short CS and ultra long TT. But we will always make sure we are aware of test a variety of geometries to be sure we are not missing out on an advantage. For example, I have found I can use a much slacker HT angle than anticipated, due to the geometry changing effect that makes it climb about 4 degrees steeper. My Meltdown Race for the Sea Otter Enduro had a 64 degree HT angle, and still climbed great.
Thanks for the explanation. I agree some are taking the long TT/short chainstays too far for where and how I ride but I do like the recent geometry trends in moderation. The steeper climbing geometry of your design sounds great to me. The best climbing bikes I have ever owned (hardtail and FS) had 90's NORBA-standard XC geometry but current trail and AM bike geometry is much more fun in almost every other way.

I hope you had a chance to try the bikes in Santa Cruz while you were here for Sea Otter.
 

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The thing is, you can't. Even if you could get the "optimum" wheel path, it would come at great compromise to some other desired quality, for example, pedal feedback through excessive chain growth. Every single parameter that a designer chooses is a compromise. Do I want a better climber or descender? Pedaler or bump performance. And it's always much more complicated than that.

The Missing Link helps bridge those compromises. A better pedaler AND better bump performance. A better climber AND a better descender. The Missing Link adds performance that is not possible with any other design or linkage.
Proof is in the riding. Bring one out to the Sedona Mountain Bike festival next spring and I'll give it a try. There are some short steep climbs within a half mile of the venue and a nice set of difficult rock steps on a jeep road that are a perfect test of your claims.
 

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Thanks for the explanation. I agree some are taking the long TT/short chainstays too far for where and how I ride but I do like the recent geometry trends in moderation. The steeper climbing geometry of your design sounds great to me. The best climbing bikes I have ever owned (hardtail and FS) had 90's NORBA-standard XC geometry but current trail and AM bike geometry is much more fun in almost every other way.

I hope you had a chance to try the bikes in Santa Cruz while you were here for Sea Otter.
I think what most designers want is for their geometry/designs be taken as a whole, which of course means riding it. For example, because the rake is a little slacker on the Meltdown compared to some comparative bikes, this adds to the front center length without adding to the reach. So adding to the TT can be detrimental to handling in that it increases the wheelbase.

Another compromise; shorter CS, at some point, require a steeper ST angle, moving the rider forward when seated, and moving the headtube further forward to maintain the same reach. A slacker ST angle can keep the rider further to the rear, not only seated, but by moving the HT to the rear to maintain the same reach.

It's all a juggling match and the proof is in the ride. (you'll start seeing tests soon)

And keep in mind that I'm claiming both steeper for climbing AND slacker for descending.

Did not get a chance to go to SC. Que lastima. But generally get to ride in a lot of awesome places. next time.........
 

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Proof is in the riding. Bring one out to the Sedona Mountain Bike festival next spring and I'll give it a try. There are some short steep climbs within a half mile of the venue and a nice set of difficult rock steps on a jeep road that are a perfect test of your claims.
Sedona, Love to. Closest I'd been was an ancient old race called Cactus Cup. No telling where we will end up. Next stop is Big bear in June.
 

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TC, so what happens under standing pedalling (in terms of the physics of the lower link and it's behavior)?

Sorry if you already answered.
 

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At the end of the day this bike follows the sames principles as any other bike. It's a Virtual Pivot with a "Spike" of Anti-squat at the beginning of the travel 180% at 0% and 120% around 25%. The Leverage Ratio has another "Spike" at the beginning of the travel where it goes really low (1.6), but around 25% it's quite normal (2.7).

If you are pedalling slowly, the bike it's going to stay around sag like any other bike and work the same as any other bike with 120% of Anti-squat. If you start pedalling really hard it's going to extend, top out, and stay there for a while, because that LR (combined with that AS Curve) works "as a trap" for the rear wheel. If you hit something and you keep going the bike it's not going to absorb the bump, but I think that there is an instinct to relax a bit when you hit something really big, if that happens the suspension can react to the bump.

Tantrum Cycles Meltdown 2017_Anti-squat.jpg Tantrum Cycles Meltdown 2017_LevRatio.jpg

Best regards,
Tony.
 

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TC, so what happens under standing pedalling (in terms of the physics of the lower link and it's behavior)?

Sorry if you already answered.
Basically, the physics aren't changing at all when standing, unless you as a rider are just bouncing around more while standing. so, it's really about the effort, the torque that you are generating, so seated or standing, if you can generate max torque, it will go to full extension and lockout (until you hit the bump).

What if you can't generate max torque? The stiffening effect will be proportional. On level ground, you cannot deliver max torque, so the stiffening affect keeps it stable, not at full extension, but at static sag level.
 

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At the end of the day this bike follows the sames principles as any other bike. It's a Virtual Pivot with a "Spike" of Anti-squat at the beginning of the travel 180% at 0% and 120% around 25%. The Leverage Ratio has another "Spike" at the beginning of the travel where it goes really low (1.6), but around 25% it's quite normal (2.7).

If you are pedalling slowly, the bike it's going to stay around sag like any other bike and work the same as any other bike with 120% of Anti-squat. If you start pedalling really hard it's going to extend, top out, and stay there for a while, because that LR (combined with that AS Curve) works "as a trap" for the rear wheel. If you hit something and you keep going the bike it's not going to absorb the bump, but I think that there is an instinct to relax a bit when you hit something really big, if that happens the suspension can react to the bump.

View attachment 1067223 View attachment 1067224

Best regards,
Tony.
Hi Tony,

At the end of the day it does, but that's why we are starting a new day! Sorry, couldn't resist. so, it must follow the same laws of physics, but the missing link adds another input tot he suspension that works in combination with the rest of the linkage.

I was wondering why your numbers are (in some cases) extremely skewed. I looked at the software you are using. It doesn't appear that it has the capability to accurately model this design (although I didn't buy it, so I'm not sure how flexible it is). Maybe it's just the inaccuracy of doing it from as picture.

To call it another "virtual pivot", is essentially a non-description, right?? That's only every non-single pivot bike ever made, from the horst link to DW. It really does nothing to differentiate any design from another. There seems to be no mention of the forces input by the missing link in your analysis. Which are very important.

But a couple of trends are correct, The motion ratio does start out very "stiff". Yes, your description of this as a "trap", kinda works. Although it has nothing to do with pedaling slowly or not. You can pedal so slow you are about to stop, but if the torque is there, so will the effect. It will reach top out and stay there as long and you are delivering the torque. Conversely, you can pedal really fast with almost no torque whatsoever. Think sprinting on level ground. In this case, the suspension would stiffen slightly, enough to keep still and at static sag level.

Now, think about getting out of the "trap". Say you are trying to climb a staircase. There is no way you can attack this at full torque. Before the rear wheel even gets there, the front wheel hits the first step and upsets the whole applecart. So the rider is continually making adjustments in weight shifts, pedal position, power delivery, etc. The missing link is then able to counter rotate and help compress the suspension at a softer than normal rate.

The missing links contribution cannot be overstated. It is continually modifying the spring force softer and stiffer than normal.

All of these forces and effects took a LONG time to work out, with thousands of iterations to get all of the effects working in right direction at the right time.
 

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Hi Tony,

At the end of the day it does, but that's why we are starting a new day! Sorry, couldn't resist. so, it must follow the same laws of physics, but the missing link adds another input tot he suspension that works in combination with the rest of the linkage.

I was wondering why your numbers are (in some cases) extremely skewed. I looked at the software you are using. It doesn't appear that it has the capability to accurately model this design (although I didn't buy it, so I'm not sure how flexible it is). Maybe it's just the inaccuracy of doing it from as picture.

To call it another "virtual pivot", is essentially a non-description, right?? That's only every non-single pivot bike ever made, from the horst link to DW. It really does nothing to differentiate any design from another. There seems to be no mention of the forces input by the missing link in your analysis. Which are very important.

But a couple of trends are correct, The motion ratio does start out very "stiff". Yes, your description of this as a "trap", kinda works. Although it has nothing to do with pedaling slowly or not. You can pedal so slow you are about to stop, but if the torque is there, so will the effect. It will reach top out and stay there as long and you are delivering the torque. Conversely, you can pedal really fast with almost no torque whatsoever. Think sprinting on level ground. In this case, the suspension would stiffen slightly, enough to keep still and at static sag level.

Now, think about getting out of the "trap". Say you are trying to climb a staircase. There is no way you can attack this at full torque. Before the rear wheel even gets there, the front wheel hits the first step and upsets the whole applecart. So the rider is continually making adjustments in weight shifts, pedal position, power delivery, etc. The missing link is then able to counter rotate and help compress the suspension at a softer than normal rate.

The missing links contribution cannot be overstated. It is continually modifying the spring force softer and stiffer than normal.

All of these forces and effects took a LONG time to work out, with thousands of iterations to get all of the effects working in right direction at the right time.
If you are going to complain about the numbers not being accurate you have to post the real ones and prove it. That's how it works, if you don't post anything the only thing I can say is that having an aproximation is a lot better than having nothing.

The program can handle your design without any problem, it's a 6-bar with the same layup as the Equilink System. I don't have a super nice picture and I know the results are not perfect, but I'm sure they are close, and I'm sure the general idea behind the system is correct.

I call it a Virtual Pivot because that's what it is, the system has one degree of freedom, and compared to the the Magic Link of the old Konas there is nothing weird going on... It follows the same rules as any other Virtual Pivot.

Best regards,
Tony.
 

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If you are going to complain about the numbers not being accurate you have to post the real ones and prove it. That's how it works, if you don't post anything the only thing I can say is that having an aproximation is a lot better than having nothing.

The program can handle your design without any problem, it's a 6-bar with the same layup as the Equilink System. I don't have a super nice picture and I know the results are not perfect, but I'm sure they are close, and I'm sure the general idea behind the system is correct.

I call it a Virtual Pivot because that's what it is, the system has one degree of freedom, and compared to the the Magic Link of the old Konas there is nothing weird going on... It follows the same rules as any other Virtual Pivot.

Best regards,
Tony.
That's how it works? I'm sorry, but I will refrain from posting proprietary information. The devil, is indeed, in the details, in terms of how the magic is accomplished. Nice try though.

If you care to do some research, please look at the tech page on Home. If you want to get deeper into the patents, you kind find links here: Home. True, I do not post an exact leverage curve or anti-squat curve or even a wheel path. Why? Because those parameters, on their own, are fairly minor in the big picture of this design. What's more, they are, for the most part, fairly meaningless to most of the market. It's easy to geek out on this kind of stuff, but it can really make peoples eyes glaze over in a hurry. Trust me, I know.

What matters is the ride. So, what I included on the website, hopefully, has a little more meaning. I show, what we call in an engineering term, the wheel rate under various conditions. The wheel rate, or force, is the rate or force seen at the wheel itself. In a simple sense, it is the spring force linked to the leverage curve. But it can be extremely manipulated by the air volume, not to mention any anti-squat characteristics. What I am trying to show on the website is what all of this really means to the rider. Nobody else really does this, they explain why their leverage curve/wheel path/anti-squat is the ideal one, but this is always subjective and difficult to prove.

My main problem with your analysis, is that, until you just posted that you didn't have a "super nice picture", you kinda represented your results as definitive and accurate. I won't even touch "an approximation is better than nothing". It kinda does a serious disservice to every engineer and designer that labors over minute details to make things right. It's also why bikes with very similar specs on paper can ride very differently. It turns out, an approximation is just fodder.

Some small points, the Felt Equilink, would technically be a 5 bar linkage (which does offer an additional flexibility over a "common" vpp) controlling wheel path and primary kinematics, with a secondary 4 bar linkage in parallel, which interacts between the 2nd and 5th link of the 6 bar linkage.

The Missing Link is also a 5 bar linkage controlling the wheel path and primary kinematics, although with quite different results. In addition, the Missing Link provides another 4 bar linkage IN SERIES, to drive the shock directly. Altogether different to the Equilink and everything else on the market.

The Magic Link, was also a (virtual pivot) 5 bar linkage to control the wheelpath, but the primary and general kinematics were influenced by the primary and auxiliary shock, which were driven interactively in series by another 3 bar linkage.

I do appreciate your attempts to analyze it, I hope I cleared up a few things for you.

cheers,

Brian
 

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Discussion Starter #37
company appears to be aptly named..
“The distance between insanity and genius is measured only by success.” :)

Not sure if it was your comment alon, Or also your (interestingly written) forum alias that made me think of that famous quote.. ;-)
 

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If you don't post any real data you are free make a lot of "Marketing Claims"... Just like in the old days.

You can say "The Missing Link removes the need to EVER use a lockout", but that's just a lie. Your system only top-out when you are pedalling really hard, the rest of the time it's active and the only way to stop an active system from bobing is having 100% of Anti-squat. Does it have 100% of AS in all the gears? Nope, that's actually impossible, so there is going to be a little bit of bob, even if you are close to 100% AS, and some people hate bob.

You can say that "The chaingrowth on this design is actually pretty minimal", but that's another lie and you don't want to post the real data because then everyone would see that you are not telling the truth.

You can say "If you are pedaling through a rock garden, the suspension will be firm enough to keep high in the travel, but not too firm to hurt traction or control". All I can say it's that your bike has a lot of Pedal-kickback and a Regressive LR, so it's not going to work as well as many other bikes in that situation. A Knolly, a Lenz or a Rocky Mountain it's going to work much better than your bike climbing trough a rock garden...

Your system is patented and you say that nobody can archive the same goals with a 4-Bar, so there isn't any risk of being copied... if there is no risk, why don't you post the real data???
 

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If you don't post any real data you are free make a lot of "Marketing Claims"... Just like in the old days.
Hi Tony, how quickly on the internet we go from "best regards" to " you're a liar!!" I wasn't trying to incite you, just pointing out a few areas where your analysis had flaws, so we could discuss things on an even ground.

It's true, I am making marketing claims. Just like every other company trying to sell something on the face of the earth. My marketing claims, (like many others), happen to be true and can be proven on a quick test ride..

I posted data that I hope makes more sense to the average rider, AND the scientist/engineer. The wheelrate I mentioned, is the end result of all the other crap we put into our suspension design, therefore most relevant. Posting leverage curves on their own without the spring force is meaningless. Why do you think so many bike reviews include the phrase "it needed more (or less) volume spacers?
 

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You can say "The Missing Link removes the need to EVER use a lockout", but that's just a lie. Your system only top-out when you are pedalling really hard, the rest of the time it's active and the only way to stop an active system from bobing is having 100% of Anti-squat. Does it have 100% of AS in all the gears? Nope, that's actually impossible, so there is going to be a little bit of bob, even if you are close to 100% AS, and some people hate bob.
Tony, please. How can you possibly claim it's a lie? Why haven't you even mentioned the Missing Link? have you manged to use its input in your program?

You are absolutely correct on one point. AS cannot achieve the results that the Missing Link can. I've said all along that the Missing Link does not rely on AS. There is a component, but it would never achieve the results I can achieve with the added input of the Missing Link. The Missing Link is independent of gears, it responds to the torque you as a rider are inputting into the ground to move forward. if you can create the same torque with a taller or shorter gear, its reaction will be the same.

The system is calibrated to top out only on a fairly step climb. This is the only time you would want the steep geometry. On level ground, it is calibrated to lock out at your static sag level. And if you are pedaling at a consistent rate, it will do exactly that. Can you make it misbehave? Of course. But not while riding like you want to ride.

If you are in a situation where you are thinking of reaching down and locking out your shock, it will already be locked out. If you are riding in alternating terrain, where you have no time (and you're too busy) to lock the shock out for a second or two, the missing link will provide that effect for you automatically, and then release when you hit the next bump.

Please look at the video of the climb on the website, Home. I will trim that one down and just post the slomo smooth climb with the roots at the top. You can clearly see the shock going to full extension and staying absolutely still at the smooth, steep beginning of the climb. then you can easily see the shock move to absorb the roots at the top and then go back to full extension lock out for the remainder of the steep climb.

I didn't fake or photoshop that video. That's me riding on some of my test trails. It really happens.
 
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