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Discussion Starter #1 (Edited)
I have been following the updates from Tantrum Cycles for a while now, just waiting to get on a demo bike to see how it feels.
Imoh the Missing Link linkage is claming to do all what I have been looking for in an All Mountain bike.

-Seamlessly and automatic raising the BB height when climbing to avoud pedalstrikes and improve the geometry for climbing.

-No bobbing even without any propedal platform, lockout or other "Anti Bob" devices like electronics or inertia controlled valves. And yet stiff as a hard tail when climbing steep, but still active to bumps to give good traction to efficiency ratio.

-Plush initial travel without wallow.

It's all well explained in video, diagram and text in the Tech web page
Technology

What's your thoughts on this?

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-No bobbing even without any propedal platform, lockout or other "Anti Bob" devices like electronics or inertia controlled valves. And yet stiff as a hard tail when climbing steep, but still active to bumps to give good traction to efficiency ratio.
Well, for one, on many bikes, it's not "bob" that decreases your efficiency, if you pedal completely smooth and get no bob, there's still squat that compresses the rear shock beyond it's sag point, as a result of the torque you supply to the chainring, which in turn tugs the rear cassette up and keeps the shock compressed. That's where the efficiency is made/lost. That they are marketing "bob" just goes to show they are trying to pander to the uninformed masses.

I don't want the rear wheel to stiffen during climbing, I want it to absorb bumps and give me traction. That's why I bought an FS bike.
 

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Haven't ridden the bike, obviously, but the design gives me three concerns

*looks like they're using chain tension to prevent chainstay growth. This makes for a ton of pedal feedback as the chainstays try to extend and pull on the chain.

*Using chain tension to 'pick up' the rider means the rider is using energy to extend the suspension with each pedal stroke. Reverse pedal bob.

*Locking out the suspension this way makes the suspension pretty unresponsive to bumps under power.

Maybe it's the biz, but by now it seems like suspensions are pretty well sorted and designers only have to tweak their parameters to get the ride character they want. Interesting design, but I wouldn't be interested without an extended dirt test ride.
 

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Discussion Starter #4
Thanx for the clarification Jayem. Bad explanation frommy side. I totally agree in what you say and Missing link is suppose to do exactly what you wrote. No squat but still active, always.

I'm a "spinner" myself and used the word "Bob" with the uniformed masses in mind.. 😉

The ting is that this linkage is supposed to be stiff when pedaling on smooth ground, from flat to the steepest climb. But still be active to absorb every bump to give you good traction.

And at the same time avoid squat by having this anti-sag function that rais the BB when climbing. Improving the ground clerence when you want it. And also steeping the head angle to give quicker steering when you want it (slow speed at step climbs)

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Discussion Starter #5
Haven't ridden the bike, obviously, but the design gives me three concerns

*looks like they're using chain tension to prevent chainstay growth. This makes for a ton of pedal feedback as the chainstays try to extend and pull on the chain.

*Using chain tension to 'pick up' the rider means the rider is using energy to extend the suspension with each pedal stroke. Reverse pedal bob.

*Locking out the suspension this way makes the suspension pretty unresponsive to bumps under power.

Maybe it's the biz, but by now it seems like suspensions are pretty well sorted and designers only have to tweak their parameters to get the ride character they want. Interesting design, but I wouldn't be interested without an extended dirt test ride.
Regarding chain tension and pedal feedback.
Since the lower part of the "Missing" link is shorter then the equivalent lower links on VPP and DW-LINK suspension, I would guess it's a good chance that it also gives less pedal feedback.
Personally I think it's a overated problem anyway.

I doubt the suspension extends with every pedal stroke. Or ever locks out completely.
If that was the case they could not state that the "Suspension does not wallow in travel due to Missing Link effects"
And "Instant reaction to bumps, even while climbing or sprinting"

They is a discussion with som deeper explanations on how this actually works
http://m.vitalmtb.com/photos/featur...423/2017-Tantrum-Meltdown,97874/sspomer,2#_=_

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Well, for one, on many bikes, it's not "bob" that decreases your efficiency, if you pedal completely smooth and get no bob, there's still squat that compresses the rear shock beyond it's sag point, as a result of the torque you supply to the chainring, which in turn tugs the rear cassette up and keeps the shock compressed. That's where the efficiency is made/lost. That they are marketing "bob" just goes to show they are trying to pander to the uninformed masses.

I don't want the rear wheel to stiffen during climbing, I want it to absorb bumps and give me traction. That's why I bought an FS bike.
Some bikes compress, but most modern bikes have a degree of anti-squat to prevent that. In the extreme, anti-squat can seriously extend the rear, only to have it compress at the top/bottom of the stroke. Think an old C'dale super v.

We're also talking about climbing efficiency, where weight transfer to the rear will cause more than static sag in the rear, resulting in slacker than static HT and ST angles, making it more difficult and less efficient to climb. This is of course made worse by the fork lengthening with less weight on the front.

Quite the contrary, the uninformed masses will have the most difficulty understanding all of the benefits. The market for this bike is the all mountain trail rider that knows what makes a good climber (steeper geometry, stiffer rear suspension) and what makes a good descender (slacker geometry, ultra plush bump absorption combined with a bottomless feel).

You say you do not want the suspension to stiffen, but i'm guessing your bike has a lockout and if you do any serious climbing, you've probably used it. You've probably also suffered for the lack of suspension while using it, and accepted this compromise as a better trade-off for efficiency. In fact, I don't think you'll find a bike on the market without a lockout of some sort, so it must be desirable at some point.

I'm personally not fan of lockouts. Much of my climbing is very short and steep, following quick short descents. I don't want to mess with the extra clutter or complication.

The Missing Link removes the need to EVER use a lockout. If you are climbing in a situation where you would want one, then you are most likely on a fairly steep, smooth climb. If you can put out that power, the missing link will not only prevent the shock from compressing, but will extend it fully for the duration, steepening the geometry by up to 4 degrees.

This would be fine on a paved road, but when you hit a bump, the Missing Link rotates in the opposite direction, encouraging the shock to compress at a softer than normal rate, while still providing steeper geometry.

Pedaling on level ground provides a nominal stiffening, enough to prevent the compression you previously mention, while still providing superior bump absorption due to the missing link assist.
 

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Nice to see some manufacturer comment, thanks for joining. Your product looks cool, and I'm all for innovation, but have to question this:
In fact, I don't think you'll find a bike on the market without a lockout of some sort, so it must be desirable at some point.
There are lots of bikes without lockouts... My kid's Process 134a (LDSP) for one. Not sure if the CTD switch on my Trance (DW) would be considered a lockout, either.
 

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Nice to see some manufacturer comment, thanks for joining. Your product looks cool, and I'm all for innovation, but have to question this:


There are lots of bikes without lockouts... My kid's Process 134a (LDSP) for one. Not sure if the CTD switch on my Trance (DW) would be considered a lockout, either.
I know this is a completely new concept. No other bike has this or has this capability. So I want to do my best to explain it and answer all questions.

Your kids process has a version of "lockout". It may not lock it up completely, but the shock has "2 position compression, pedaling and open". Call it stiffening instead of lockout. Your CTD does the same thing, climb, trail descend. You select a stiffer damping setting to help pedaling and/or climbing. And if you're on a smooth climb, a complete lockout is better.
 

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Haven't ridden the bike, obviously, but the design gives me three concerns

*looks like they're using chain tension to prevent chainstay growth. This makes for a ton of pedal feedback as the chainstays try to extend and pull on the chain.

*Using chain tension to 'pick up' the rider means the rider is using energy to extend the suspension with each pedal stroke. Reverse pedal bob.

*Locking out the suspension this way makes the suspension pretty unresponsive to bumps under power.

Maybe it's the biz, but by now it seems like suspensions are pretty well sorted and designers only have to tweak their parameters to get the ride character they want. Interesting design, but I wouldn't be interested without an extended dirt test ride.
Chain tension affects ALL suspension designs. That's how anti-squat works. Yes, the reaction at the tire contact patch is part of the equation, but that reaction doesn't exist without chain tension.The design does not use chain tension in the traditional sense. The chaingrowth on this design is actually pretty minimal, it does not need growth to achieve the desired effect. No pedal bob, or reverse pedal bob.

Read the full description, it locks out fully and goes to full extension....until it hits a bump, which causes the missing link to rotate in the direction to compress the shock, offering a softer bump response than normally possible.

That's the whole point. It locks out and extends to steepen geometry when you need it and still complies to bumps when required.

Bikes are pretty well sorted, to a point. The point being you can only do so much with conventional suspension geometry and layouts. Then you have to start adding crutches like lockouts and pedaling platforms, which generally are not good for bump performance.

So you have to come up with something pretty special and unique to offer a new performance capability that no other bike has or can have. That's what we've done.
 

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Well, for one, on many bikes, it's not "bob" that decreases your efficiency, if you pedal completely smooth and get no bob, there's still squat that compresses the rear shock beyond it's sag point, as a result of the torque you supply to the chainring, which in turn tugs the rear cassette up and keeps the shock compressed. That's where the efficiency is made/lost. That they are marketing "bob" just goes to show they are trying to pander to the uninformed masses.

I don't want the rear wheel to stiffen during climbing, I want it to absorb bumps and give me traction. That's why I bought an FS bike.
Well, that excellent and simple explanation finally made this topic click for me...thanks!
 

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I'm no engineer or suspension expert but this design makes sense to me. I refuse to believe bike designs have already hit there pinnacle and all that's left is minor tweaking.
 

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Discussion Starter #12
Well, that excellent and simple explanation finally made this topic click for me...thanks!
Maybe not that excellent since they are actually not marketing "Bob" att all.
I suggest you take a closer look at the tech page http://www.tantrumcycles.com/technology.html
Don miss out on watching the well explaining video that makes it easier to understand how all this is possible with out any remote lockout/TCD/pedal platform levers on the bars or shock, electronics or other gizmos I don't want to fuzz with besides gearing, braking and adjusting my remote seatpost as I frequently do on most trails I prefer to ride.
The more technical (for my ability) the more fun.
I hope to get to ride a demo bike soon.
I suspect this can be what I have been waiting for trough all this year's of marketing hypes.


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Maybe not that excellent since they are actually not marketing "Bob" att all.
I suggest you take a closer look at the tech page Technology
Don miss out on watching the well explaining video that makes it easier to understand how all this is possible with out any remote lockout/TCD/pedal platform levers on the bars or shock, electronics or other gizmos I don't want to fuzz with besides gearing, braking and adjusting my remote seatpost as I frequently do on most trails I prefer to ride.
The more technical (for my ability) the more fun.
I hope to get to ride a demo bike soon.
I suspect this can be what I have been waiting for trough all this year's of marketing hypes.


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I am more about the application of what he said outside of just this suspension design. I definitely will watch those videos and learn about this design, but my understanding of what impacts suspension while peddling has been hazy and Jayem helped with that regardless of what Tantrum cycles and their suspension.
 

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Your kids process has a version of "lockout". It may not lock it up completely, but the shock has "2 position compression, pedaling and open". Call it stiffening instead of lockout. Your CTD does the same thing, climb, trail descend.
The P134a doesn't have a lockout, just adjustable rebound. Not saying it might not benefit from one, but it's far less bobby than my FSR was.
Agree that CTD could be construed as a lockout of sorts, but I leave it in T all the time, so it may as well not be there. Pedal bob is a nonissue, and it's way active on uphill terrain.

Your design may very well be the magic bullet the industry's been waiting for... hell, you could be the next Dave. But given all the respect seemingly low-tech designs get, I'm not sure pedal jack is the coming thing.

Then again, I spin a 66*HTA uphills and haven't died yet.
 

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Discussion Starter #16 (Edited)
I am more about the application of what he said outside of just this suspension design. I definitely will watch those videos and learn about this design, but my understanding of what impacts suspension while peddling has been hazy and Jayem helped with that regardless of what Tantrum cycles and their suspension.
That's all good. Since it was me that drags the word "Bob" into the discussion I just felt it was appropriate to point out that Tantrum is not marketing any anti "Bob" feture at all.
They are actually just mention the word Bob one time on ther website, an that was in relation to other suspension designs that have to much anti-squat, or I suppose any kind of automatic and "adaptive" sag adjustment, as afa i can understand, Missing link can give 100% of?

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The P134a doesn't have a lockout, just adjustable rebound. Not saying it might not benefit from one, but it's far less bobby than my FSR was.
Agree that CTD could be construed as a lockout of sorts, but I leave it in T all the time, so it may as well not be there. Pedal bob is a nonissue, and it's way active on uphill terrain.

Your design may very well be the magic bullet the industry's been waiting for... hell, you could be the next Dave. But given all the respect seemingly low-tech designs get, I'm not sure pedal jack is the coming thing.

Then again, I spin a 66*HTA uphills and haven't died yet.
Count your kid's 134 as one more bike no longer available without some kind of lockout. Even at the lowest price point, that model now has one.

Controlling pedal induced suspension motion remains the biggest goal of all bike brands. Many are happy to use the most simple suspension and add a shock that is quite capable of helping the situation (as shock makers are continually coming up with new ways to help), although ALWAYS at the expense of bump absorption. Most brands have settled on some variation of chain tension controlled anti-squat, and yet they still all have a shock/damper with some sort of pedaling assistance/stiffening effect. Some have additional setting like the Scott variable travel.

So the entire industry is continually focused on this problem. Why? As good as bikes and suspension are, they can and will get better. Always.

There's no magic bullet. Bikes are good and fun. They always were and always will be. And there will always be people like myself wanting to make them better. in this case, I have come up with something that no other bike has and no other bike can do. Would you disagree with the following?

1) in general, for climbing, steeper geometry is better (say 70-78 degree HT), for descending, slacker is better (say 62-70).

2) in general, for climbing, a shorter travel bike, maybe with a firmer suspension to counteract weight transfer, would be beneficial

3) on a paved, smooth climb, no suspension would be better

4) for descending, a longer travel, more bump responsive suspension would be better.

Those are the characteristics that the missing link can provide. With no loss of active suspension when needed. Ever.

Pedal jack WAS the coming thing. It's exactly what you and every other anti-squat suspension rider are using. The simplest form was an old Super V or Super 8. Pedal jack in the extreme. The current forms are simply a more refined version.

The Missing Link is completely different. Understand how the link can take ALL of the forces on the chainstay, from bump, pedaling, braking and continually modify the force on the shock, from helping it compress, to hindering it's compression. All at the right time for the conditions. You will have a better understanding of what's happening.
 

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Very interesting. So based on the diagram on the technology page, it makes sense. One comment, the green and red arrows point to the point where the lower link pivots on the frame. This point is stationary, relative to the frame. If the red and green arrows pointed to the pivot point where the chain stay attaches to the lower link, it would be more clear, because, pedal forces pull this pivot closer to the bb, extending the shock.

I'm with others though, I have some natural skepticism that it will feel active and jack free during climbing. I don't see chain growth in the diagram but it's hard to visualize the physics of how bumps will affect compression under full pedal power.
 

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Very interesting. So based on the diagram on the technology page, it makes sense. One comment, the green and red arrows point to the point where the lower link pivots on the frame. This point is stationary, relative to the frame. If the red and green arrows pointed to the pivot point where the chain stay attaches to the lower link, it would be more clear, because, pedal forces pull this pivot closer to the bb, extending the shock.

I'm with others though, I have some natural skepticism that it will feel active and jack free during climbing. I don't see chain growth in the diagram but it's hard to visualize the physics of how bumps will affect compression under full pedal power.
Hi Proctor, thanks for the input. The red and green arrows don't actually point to that pivot, rather they come from it. The intent is to show the leverage (torque) that the force on the chainstay and on the the link as it rotates around that pivot. It is the link's rotation around that frame pivot, that makes all the magic happen, not the chainstay rotation on the link.

Skepticism is good, it keeps things in check. Of course, there's nothing like a ride. Expect to see some test rides in the nearish future.

In the meantime, imagine the chainstay pushing and pulling fore and aft on that link as it encounters drive and bump/braking forces. This pushing and pulling is translated through the Missing Link to the top of the shock, where it continually can stiffen, soften of be neutral (coasting on smooth, level ground). This is completely unlike the way a high pivot or other high anti-squat (two short links) delivers pedaling/drive force into the system, which are also unable to alter the spring force relative to horizontal forces on the chainstay..

When you are under FULL power, almost by definition, you are on a very steep, smooth climb. If you encounter any bumps, typically, you will have to modulate your pedal stroke slightly, timing it with the bump. as you do this, the force of the bump drives the chainstay to the rear, assisting compression of the shock. In, fact, it does this at a very low spring force at the wheel, lower than the normal spring rate of the shock would deliver under the same circumstance. So the bump is easily absorbed and you are back at full power and full "lockout".

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. In a rock garden, you simply can't pedal hard enough to "lock out" the suspension (nor can you on level ground). And the bump force is continually pulling the chainstay back, assisting bump response, allowing the wheel to easily get up and over rocks or obstacles. It's all a continual force battle. I've done a lot of work to balance those forces to a desirable effect.

There's a lot going on and it's hard to decide how best to illustrate it and get the point across without losing interest (see my responses).

I hope this helps.
 
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