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What does graph say about suspension performance
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Posted 1 year ago #
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It says its not about the bike...
Posted 1 year ago # -
do they show linear but falling rate (at a constant rate)
and rising then falling and falling then rising rate suspension designs?Posted 1 year ago # -
that Instantaneous ratio doesn't mean a lot?
Posted 1 year ago # -
What is each one trying to achieve?
Posted 1 year ago # -
Where's the graph from?
Posted 1 year ago # -
Looks like it is the ratio between shock movement to actual vertical wheel at a given travel, so the linkage rates.
Posted 1 year ago # -
Yellow and red lines show progressive rate.
Blue shows progressive to begin with until mid-travel and then falling rate.
Green shows falling rate to start with and then at 1/3 travel or so it starts going onto a rising/progressive rate.The green line being a Blur shows that the sag point that SC always go on about for their VPP design is where the line moves from falling to rising rate.
Posted 1 year ago # -
You can lead a donkey to water, but you can't make it interpret an instantaneous leverage ratio graph?
Posted 1 year ago # -
Where's the graph from ooOOoo?
Posted 1 year ago # -
well, given it's from a trek bloggy thing one assuems they're saying that the blue line is a 'good thing' and that the others aren't...
Posted 1 year ago # -
Trek don't use DW link though.
Posted 1 year ago # -
Thank you sam
. Is this for your dissertation or something ooOOoo?
Posted 1 year ago # -
Is there a 'best' line?
Posted 1 year ago # -
Rickos - my mistake, maybe it's the red one!
Although it must be an old graph.
Posted 1 year ago # -
I think it says that people will always differ when they define what a good linkage set up will be...
Posted 1 year ago # -
you need the characteristics of the shock to interpret anyway, don't you ?
(and some chicken entrails)Posted 1 year ago # -
The rear suspension unit would/should be valved in relation to the leverage ratio characteristics of the specific linkage.
The trek and specialized linkages being according to this graph relatively flat curves with a falling rate, however the trek linkage has a lower leverage ratio I.e less force upon the shock through out the stroke/travel of the suspension therefore the shock could be valved/shimmed less to produce the same damping characteristics.Posted 1 year ago # -
I just want to understand it.
I can see where each one is falling or rising.
Why would each company do that?
Why such a difference between the green & the blue?Posted 1 year ago # -
They do it to give a certain ride characteristic and then use marketing babble to say why theirs is better.
Posted 1 year ago # -
Is that the new 2012 Olympics logo? Better than the last one!
Posted 1 year ago # -
They would be trying to iron out the rising rate that an air shock would naturally give at a guess... only the fuel and assuming SJ is stumpjumper look to anything like how I would have expected with a slight tailing off of the leverage as the shock compresses.
Posted 1 year ago # -
What santa cruz says regarding Vpp:
VPP Linkage:
VPP suspension designs balance different forces to
eliminate unwanted compression without limiting bump absorption.
The downward force on your pedals pushes most full suspension bikes down, resulting in unwanted suspension compression. VPP bikes use a patented link configuration and axle path to apply some of the pulling force from the
chain to counteract that motion caused by pedaling.
Because the forces are balanced, VPP bikes remain able to absorb bumps when pedaling, unlike other designs that effectively lock out the rear suspension by applying too much chain pulling force. What you end up with is plush
travel with no pedal-induced compression or lockout and no need for manual lockouts or other compromises.What ibis has to say about the DW mojo:
How The DW-Link Suspension Works on the Mojo Carbon
Position Sensitive Anti-Squat by Dave Weagle
As bicycle suspension systems become more and more refined, designers strive to reduce weight, increase lateral stiffness, travel, and traction, and at the same time improve efficiency. As suspension travel increases, improvements in traction and comfort are realized, but maintaining an efficient ride becomes a greater challenge. The extra comfort and traction afforded by suspension is usually accompanied by a noticeable compromise in the efficiency of the bicycle in general. That is, you don't go as fast or as far for a given amount of effort. There have been numerous attempts to devise a system that would give good performance over the bumps and not waste any precious energy due to unwanted suspension movement. The patented dw-link is the most effective solution thus far in achieving that goal. To understand the theory behind the dw-link let's start with mass transfer. Mass transfer is a part of any movement; in particular we are concerned with the transfer that happens when you accelerate a bicycle.
A bicycle has the highest ratio of center of mass height to wheelbase of any vehicle (other than a unicycle). In the accompanying illustration, (1) represents the center of mass. Mass transfer happens on any type of bicycle, from road bikes to full downhill rigs. Every time you accelerate, your mass transfers rearward on the bike (2). When you ride a wheelie, all of your mass transfers to your rear wheel. When you do an endo, all of your mass transfers to the front wheel. Anyone who has ridden a bicycle can probably relate to this!
Unchecked, your rear suspension will react to this mass transfer by compressing and rebounding with each acceleration. The suspension's purpose is to absorb bumps, reduce vibration, and maintain grip through vertical compliance, and will compress due to acceleration unless stopped by shock damping or a counter-force from the suspension.
If there was no damper attached to your suspension (in other words if it were merely a spring), every suspension compression would be followed by an immediate and forceful rebounding force. All of the energy put into the spring would be released back into the suspension like a pogo stick. This would result in the system vibrating uncontrollably and would be more of a detriment to traction and comfort than an aid. To control this situation, a suspension system uses a damper to subdue spring oscillations and rebound forces. Many suspension systems sold today rely on an additional type of damping to in order to control their reaction to mass transfer. The use of heavy compression damping of the suspension at low shaft speeds has become a common feature on bicycle suspensions. So what's wrong with using damping to reduce the unwanted suspension movement?
A damper controls spring oscillations and rebound forces by converting mechanical energy to heat and dissipating it. The damper (your rear shock) and its ability to convert mechanical energy into heat is a double-edged sword. With heavy compression damping, when you accelerate a vehicle and the suspension compresses, a significant percentage of that energy is converted to heat and dissipated rather than used to drive the wheel. If the effects of mass transfer can be countered without excessive shock damping (4), then you can use the saved energy to move the bike forward, resulting in a more efficient suspension!
dw-link counters the effects of mass transfer with the world?s first suspension using a patented position sensitive anti-squat response.
You might be asking yourself, "What exactly is 'position sensitive anti-squat''? Anti squat is a force that balances the effects of mass transfer on the suspension, giving the best possible bump compliance, while at the same time providing excellent energy efficiency. There are two forces that combine to create anti-squat; chain pull and driving force. Chain pull force is multiplied through your rear cogs and wheel as a lever creating driving force. Because of this leverage, driving force is always the greater than chain pull force.
Mass transfer and driving force are not accounted for in most suspension designs and analysis to date, thus missing the primary cause of and respective solution to unwanted suspension movement. That is, designers have worked on solving the lost energy problem by neutralizing the effects on the suspension from chain tension but have missed or ignored mass transfer and driving force, leaving the true movement (squat) from acceleration unsolved.
The dw-link patents and suspension designs are based on solutions that have resulted from this important observation. The dw-link creates a balancing force to eliminate the squat caused by mass transfer. This force is carefully tuned for near 100% anti-squat in the first and second portions of the travel with a lessening anti-squat response deeper in the travel to reduce pedal feedback (3) to imperceptible levels. This allows the suspension to feel very efficient with minimal shock damping while also exhibiting excellent performance in traction and braking with low pedal feedback.
Check out the animation of the dw-link equipped Mojo in action.Summary:
dw-link is the world's first suspension system that takes into account mass transfer and uses a position sensitive anti-squat response to balance it. The end result is that the suspension can use much less compression damping than other systems, increasing traction and conserving energy at the same time. Real world experience bears this out with the dw-link designs consistently getting rave reviews from riders and magazines.For the graphics: http://www.ibiscycles.com/tech/dw_link/
I'll leave you to draw your own conclusions
Same problem different approaches
Posted 1 year ago # -
interestingly ( for me ) the blue and green are opposite but around the area of ride height and beyond between 1/3 and 1/2 travel they would both feel very simular
but then the blue one with the falling change of rate would use it;s travel quicker and the green with it's rising change of rate wouldnt ,
this is with a linear rate spring but with an airshock it would help the blue bike possibly giving the bike a more linear rate change
but remember the rate change also applies to the damping
it's a whole can of worms,,
Posted 1 year ago # -
Pffft, you're all reading too much into it. It says that the mojo and the blur have more travel, and are therefore more radcore. Science fact.
Posted 1 year ago # -
Posted 1 year ago # -
blah blah blah, we've discovered something everyone else has missed. The dw-link patents and suspension designs are based on solutions that have resulted from this important observation.
Why does this sound like one of those shite internet ads/spams about a new pill that'll make you 60% lighter while you still eat cake?
And I've got an ibis and like dw link, it's just this sounds sooooooo cheesey!!
Posted 1 year ago # -
sorry forgot to 'cheese edit', most marketing is cheesy as thou isn't it
Posted 1 year ago # -
Thanks loco & ade, you guys have given the clearest answers yet.
And thank you mushrooms
I still don't understand the big difference between the Mojo & the Blur - both use air shocks, so why do they behave so differently-
Is it to do with the wheel arc, or something that you sort out with a different tune on the shock?Posted 1 year ago # -
I think it shows that if you were to strap a Mojo to a Blur you would get nearly the same Instantaneous Ratio as a Fuel.
To be honest I'm not sure how useful this fact is.
Posted 1 year ago #
Topic Closed
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