[Pslide]

I think it's funny how much time and effort has been put into analyzing bike suspension in the vertical plane, and how little time has been spent on analyzing how a bike actually handles outside of a vertical plane - which is just as critical.

Not to say today's bikes haven't been well developed for cornering, but I've just never seen any theory on the subject. Is there anything analytical out there? I know it has been done extensively for motorcycles, but a pedal bike is so much different...

It's funny to talk about compromises in a bike suspension in a 2D sense without knowing what effect those compromises will have in 3D...

Just my Friday brain fart.

 

[time-bomb]

I think it's funny how much time and effort has been put into analyzing bike suspension in the vertical plane, and how little time has been spent on analyzing how a bike actually handles outside of a vertical plane - which is just as critical.

Not to say today's bikes haven't been well developed for cornering, but I've just never seen any theory on the subject. Is there anything analytical out there? I know it has been done extensively for motorcycles, but a pedal bike is so much different...

It's funny to talk about compromises in a bike suspension in a 2D sense without knowing what effect those compromises will have in 3D...

Just my Friday brain fart.

Moar importantly, how far beyond the sag is this rider......I noticed he isn't pedaling

 

[rbx]

[/QUOTE]
I think the original question has been answered at this point. I think that's why we've seen more and more long travel bikes with short bar four link system in the last several years (at least it appears that way to me)- it allows the designer to better manipulate axle path and anti-squat values, but you can still only go so far in terms of rearward axle path without using an idler or gearbox due to chain extension -which leads to drive train inefficiency. So these bikes tend to start out with a rearward axle path for the first half of the suspension compression and then go more vertical/inward to manage chain extension.
[/QUOTE]

The classic horst link bike can still have the right amount of anti-squat while reducing forces on each pivot(because there spred farther apart) and the longer parallel links allow for more active braking.(IC farther ahead)

The short link bikes have still not won me over

 

[Slater]

The classic horst link bike can still have the right amount of anti-squat while reducing forces on each pivot(because there spred farther apart) and the longer parallel links allow for more active braking.(IC farther ahead)

The short link bikes have still not won me over

Very well said.

 

[ska todd]

Any of them, bike designers, can bash at Linkage as much and long as they want. Till they don't show at least some outputs from their ultimate all-physics calculation-simulation-validation software I'd told them to be more quite.

And is the Colonel or Coca Cola gonna reveal their secret ingredients for free? Why should _dw or any other engineer in this industry? That is how they make their living. They are professionals. They have spent considerable time, effort, and in many cases money to develop tools and processes to allow them to better do their jobs. If there were a freebie tool out there to allow them to do it they surely would. Some might not have the means, knowledge, or desire to do this so to them a freeware program like Linkage could be of use.

It's funny to imagine that manipulating pics can prevent anyone from copying design of a bike that can be purchased and copied afterwards. If I was to copy a Sunday, I would buy several of those frames from different batches to minimize error.

It does not keep a large guy from doing it but surely it keeps the smaller guys and the other frame vendors from quickly, and freely, doing it. If someone has the means they can, and will, go the extra mile. If it's cheap and easy to CYOA to a degree, why wouldn't you?

disclaimer: I am fairly drunk right now.

Score!

Yes but this is the bike industry, it's run by professional amateurs.

What industry isn't? Hell, the "professionally run" industries like banking, finance, insurance, and auto have been the ones being bailed out by the Feds.

As I was once told early in my career, and as I have oft quoted, "This is not an industry, it's a loose connection of dickheads & deadbeats."

The short link bikes have still not won me over

And this is the joy of the bicycle world! If you don't like a particular design/brand/color/etc chances are one of the other several dozen guys out there makes something that will set your loins on fire. I don't think _dw or any other guy in this industry will doubt that. Hell, that is one of the reasons guys like _dw or Jeff Steber or David Earle or Cesar Rojo or Joe Graney have gone and created multiple designs for their brands or their clients. There is a broad spectrum of tastes, preferences, opinions, expectations, skill sets, and financial situations in the cycling world. If you can't find a bike in the market now that doesn't put a smile on your face and inspires you to get out and ride, then seriously you must not like cycling and should consider a different sport!

-ska todd

 

[dhkid]

OT: bit random but that is a friend of mine, bismo from indonesia, riding the trail 'cikole' in bandung, indonesia. weird how small the internet makes the world.

 

[Honus]

The classic horst link bike can still have the right amount of anti-squat while reducing forces on each pivot(because there spred farther apart) and the longer parallel links allow for more active braking.(IC farther ahead)

The short link bikes have still not won me over

The short link bikes haven't completely won me over either but I do recognize good engineering when I see it. I personally favor high pivot rearward axle path designs just because that is what feels right to me- and high pivot bikes have issues as well.

Show me a Linkage design for an 8" travel Horst link bike that has a rearward axle path (and preferably linear wheel rate) with good anti-squat numbers/pedal feedback throughout its travel. Short chainstays would be nice as well, but that's just me. Most every Horst link bike I've seen has a vertical to forward axle path -which is fine if that's your cup of tea.

Regarding pivot forces it's not a problem if they are properly engineered and manufactured correctly. If you wish to discuss things like swingarm rigidity, bearings vs bushings and Coulomb damping I'll be happy to oblige.

As always it's simply a matter of different horses for different courses. Find out what works for you and go forth.

 

[Pslide]

Show me a Linkage design for an 8" travel Horst link bike that has a rearward axle path (and preferably linear wheel rate) with good anti-squat numbers/pedal feedback throughout its travel.

 

[Honus]

I am familiar with that bike- but that's not what I asked for. I asked for the numbers... The comparison was to a DW link which does not have an idler- try to keep the drivetrain efficiency the same so we're comparing apples to apples.

 

[Steve M]

I think it's funny how much time and effort has been put into analyzing bike suspension in the vertical plane, and how little time has been spent on analyzing how a bike actually handles outside of a vertical plane - which is just as critical.

Not to say today's bikes haven't been well developed for cornering, but I've just never seen any theory on the subject. Is there anything analytical out there? I know it has been done extensively for motorcycles, but a pedal bike is so much different...

It's funny to talk about compromises in a bike suspension in a 2D sense without knowing what effect those compromises will have in 3D...

Just my Friday brain fart.

Bike suspension is only planar, and the bike is typically leaned into corners at an angle that means the forces going through the suspension are fairly close to being in that plane; this isn't a car that suffers from body roll or lateral load transfer that we're talking about.

Dave, post an anti-squat vs travel graph for one of your DW link bikes, because the ones I've had a play on bobbed like nothing else.

haha. Why would anyone give up their hard-earned information, and the result of their years of development just because some random on the interweb asked for it? Like Ska Todd says, that's like expecting Coca Cola to tell you their exact recipe, good luck with that.

I own a Sunday (actually it's for sale, wanna buy it? ) and while it's not completely bob-free, it's better than any other DH bike I've ridden. I'm also not using the intended 40t ring and I'm taller than average, so the anti-squat values aren't what DW originally calculated for. I've ridden Hollowpoints that bobbed a lot if there was too much sag - if you're outside the intended sag range then of course it's not going to pedal as it was designed to.

 

[Pslide]

Bike suspension is only planar, and the bike is typically leaned into corners at an angle that means the forces going through the suspension are fairly close to being in that plane; this isn't a car that suffers from body roll or lateral load transfer that we're talking about.

Not sure I agree. Look at that picture I posted - the loads going through that suspension are far from planar, and the riders CG is way out of plane.

That aside, the kinematics are still planar, I'll give you that.

My point was, given a bike in the condition shown in the picture, no one can tell me analytically how one suspension will behave compared to another. How will that particular bikes CC influence how that corner is schralped vs. the CC on a DW link? Nobody knows, but they should.

 

[Vrock]

Bike suspension is only planar, and the bike is typically leaned into corners at an angle that means the forces going through the suspension are fairly close to being in that plane; this isn't a car that suffers from body roll or lateral load transfer that we're talking about.



haha. Why would anyone give up their hard-earned information, and the result of their years of development just because some random on the interweb asked for it? Like Ska Todd says, that's like expecting Coca Cola to tell you their exact recipe, good luck with that.

I own a Sunday (actually it's for sale, wanna buy it? ) and while it's not completely bob-free, it's better than any other DH bike I've ridden. I'm also not using the intended 40t ring and I'm taller than average, so the anti-squat values aren't what DW originally calculated for. I've ridden Hollowpoints that bobbed a lot if there was too much sag - if you're outside the intended sag range then of course it's not going to pedal as it was designed to.

It's not Rocket Science, and we already know how it works, it's just a question of numbers, If DW wants to bash the program he should say how far off are the models. If not, he should remain quiet as someone else said.

What damage can cause to post the real numbers of an Iron Horse for example??? the company is dead and DW-link has evolved so it would be harmless.... But I'm sure he would never post anything.

 

[Steve M]

It's not Rocket Science, and we already know how it works, it's just a question of numbers, If DW wants to bash the program he should say how far off are the models. If not, he should remain quiet as someone else said.

What damage can cause to post the real numbers of an Iron Horse for example??? the company is dead and DW-link has evolved so it would be harmless.... But I'm sure he would never post anything.

The program has been discussed before, basically the issue with it is clicking on points on a picture just isn't a very accurate way of putting data in. For DW-link bikes (and most other 4-bar linkages with short links) you have to be very accurate to actually get a good model of the system. Earlier versions of Linkage didn't have any anti-squat calculations, in fact the first gen that DID have anti-squat calculations used the wrong method anyway (that method is still included in the latest version) which should actually be used to calculate anti-rise not anti-squat, and the original versions wrongly claimed to be showing "chain extension" when in reality what they were showing was the distance change between BB and axle. As mentioned before, the maths used in Linkage are accurate, but the method of inputting geometry information is not. If you can put exact data in, you'll get exact results out.

I really don't get how you expect him, or any other company for that matter, to publicise exact info on performance parameters when it is precisely that information that allows his system to work better than his competitors. It's like expecting BMW to give you exact nozzle geometry for one of their direct-injection fuel injectors. Sure the dw-link characteristics he's using now might be different but I'd be pretty confident they're not MARKEDLY different. If you really wanted that information you'd spend half an hour properly measuring up the frame, it's not rocket science.

Really, use your head and stop making unrealistic demands.

 

[Steve M]

Not sure I agree. Look at that picture I posted - the loads going through that suspension are far from planar, and the riders CG is way out of plane.

That aside, the kinematics are still planar, I'll give you that.

My point was, given a bike in the condition shown in the picture, no one can tell me analytically how one suspension will behave compared to another. How will that particular bikes CC influence how that corner is schralped vs. the CC on a DW link? Nobody knows, but they should.

Well structural stiffness aside, it's obviously only going to be the forces in the plane of the suspension that have any bearing on the suspension, and that the suspension will have any bearing on. Actually DW has discussed how axle path affects load transfer during cornering before, search "center of traction" for starters. Relative load distribution is something that changes according to suspension position in both pitch and bounce (ie independent and simultaneous movement of front and rear axles), and the rider can only move so fast to compensate for those changes. However, within comparable designs, the difference in axle path is quite small in terms of rate of weight distribution variation. Once you get significantly more forward or rearward axle paths then the difference is more noticeable.

 

[Vrock]

The program has been discussed before, basically the issue with it is clicking on points on a picture just isn't a very accurate way of putting data in. For DW-link bikes (and most other 4-bar linkages with short links) you have to be very accurate to actually get a good model of the system. Earlier versions of Linkage didn't have any anti-squat calculations, in fact the first gen that DID have anti-squat calculations used the wrong method anyway (that method is still included in the latest version) which should actually be used to calculate anti-rise not anti-squat, and the original versions wrongly claimed to be showing "chain extension" when in reality what they were showing was the distance change between BB and axle. As mentioned before, the maths used in Linkage are accurate, but the method of inputting geometry information is not. If you can put exact data in, you'll get exact results out.

I really don't get how you expect him, or any other company for that matter, to publicise exact info on performance parameters when it is precisely that information that allows his system to work better than his competitors. It's like expecting BMW to give you exact nozzle geometry for one of their direct-injection fuel injectors. Sure the dw-link characteristics he's using now might be different but I'd be pretty confident they're not MARKEDLY different. If you really wanted that information you'd spend half an hour properly measuring up the frame, it's not rocket science.

Really, use your head and stop making unrealistic demands.

It's not unrealistic, many others companies post that kind of information: Banshee, Cannondale, Trek, MSC, Santa Cruz... Some of them give more info than others but it's not difficult to find companies giving you real info about their bikes.

DW on the other hand gives very little info, he post a lot in the forums, but in the end, he does not tell us much.

 

[Steve M]

It's not unrealistic, many others companies post that kind of information: Banshee, Cannondale, Trek, MSC, Santa Cruz... Some of them give more info than others but it's not difficult to find companies giving you real info about their bikes.

DW on the other hand gives very little info, he post a lot in the forums, but in the end, he does not tell us much.

I've NEVER seen anti-squat profiles posted by any of those companies, the closest thing I've ever seen is Jeff Steber posting up leverage rate curves of the M6 and 951 on MTBR. Feel free to link me to the evidence to the contrary. Really, all you're doing is having a bitch that somebody won't give away the information that their livelihood is based on, for free, when you could actually GET that information if you'd just get off your arse and go measure up a couple of bikes. No industry leading engineer/designer in their right mind would be giving up the info you're demanding from DW.

 

[Steve M]

Reviving this thread because of something I've noticed with my current and previous Banshee Legends that's relevant to the original post - the Legend pedals noticeably better with a 300lbs/in spring than a 350 (with me @ 200lbs aboard, 37t ring). With the 350lbs/in spring and about 30% sag, the suspension actually extends during each pedal stroke, which creates a noticeable amount of bob and the feeling that each pedal stroke is somehow levering the back of the bike up. With the 300lbs/in spring giving about 35% sag, the anti-squat has decreased significantly and the bike actually pedals much better - very little noticeable bob and no real sense that the bike is just folding itself in half instead of turning your efforts into speed.

If this bike had a constant amount of anti-squat even between say 25-40% travel, it'd have a wider range of potential setups before you started compromising pedalling performance. In my particular case this isn't a big deal because the sag/spring rate I want happen to coincide with the pedalling sweet spot (obviously because the bike was designed to pedal well at this particular point in the travel too), but some people like stiffer or softer setups that'd end up compromising the pedalling somewhat.

 

[Vrock]

You can't have it all, it's "impossible" to keep the AS even around the SAG point and then drop it like crazy to reduce pedal kickback.

 

[Slater]

From the Legend in Linkage with a 37/17 the approx AS numbers are:

30%: 180%
35%: 160%

This is considerably higher than most any DH bike I can think of. I find it interesting that you say they "designed it" for strictly 35% sag and that's why it pedals worse at 30% sag. It seems more likely that this is an example of the upper end of acceptable anti-squat forces, before they induce bob by jacking up the mass and then letting it fall, to create something similar to low AS induced "bob".

None the less, I can see how an AS "platform" around the sagpoint would be beneficial.

 

[Kamanchi]

If you don't have the right amount of anti-squat does that mean you will lose the race?

 

[Steve M]

You can't have it all, it's "impossible" to keep the AS even around the SAG point and then drop it like crazy to reduce pedal kickback.

Been discussed, it's been done - a little-known system referred to as "dw-link". Already explained how it works.

From the Legend in Linkage with a 37/17 the approx AS numbers are:

30%: 180%
35%: 160%

This is considerably higher than most any DH bike I can think of. I find it interesting that you say they "designed it" for strictly 35% sag and that's why it pedals worse at 30% sag. It seems more likely that this is an example of the upper end of acceptable anti-squat forces, before they induce bob by jacking up the mass and then letting it fall, to create something similar to low AS induced "bob".

None the less, I can see how an AS "platform" around the sagpoint would be beneficial.

If you're getting those numbers from either of the Legend models in the Linkage bike library, keep in mind that neither of them has a high accuracy rating, in fact the model of the Mk2 is rated one star out of five. I wouldn't be putting any faith in those figures, and I believe that is why DW is so critical of the program. Short links mean just a few mm inaccuracy can make those values completely invalid. Literally - moving one pivot point just 3mm in the Mk2 model drops the anti-squat percentages at 30/35% travel to 149%/130% with that gear ratio, so I'm more than just a little bit skeptical of the accuracy of the entire model. The difference between the two models as far as pivot placement goes (relative to the BB) is more than 15mm in some cases! I have the two generations of Banshee frames right here and the pivots I'm comparing are very close to one another (talking like 2mm or so, possibly less) - shows right there just how inaccurate the models can be. You're also relying entirely on Linkage's preset values for centre of mass, which is rounded vertically to the nearest 100mm! All the DW-link bikes have even shorter links than the Banshee, so any and all inaccuracies with the linkage geometry will be magnified significantly - you can probably see why DW doesn't like the program. The info you get out is completely dependent on the data you put in, which in this case appears to be approximately useless crap.

If you want to see really high anti-squat values, check out the Orange 223, original Karpiel frames (some of which had anti-squat values around the 300% mark), GT LTS, Sunn Radical Plus, etc.

 

[Steve M]

If you don't have the right amount of anti-squat does that mean you will lose the race?

Yes, undoubtedly. Nobody has ever won a race on a crap bike.

 

[monkeyfcuker]

Socket are we going to be seeing a write up from you about the new Legend? Pref with comparisons to the Sunday

 

[fluider]

Nobody can say the Linkage program is accurate or inaccurate because none of that is 100% true. Short link designs are not alpha-omega of the world and preset values like CoM can be easily modified if one knows the more correct position. The weakness of locating pivots on photos that are often distorted can be eliminated if you find allied person in manufacturers team who will give the correct positions or can be slightly supressed by taking a picture of bike from very long distance like 10m with camera pointed at frame's geometrical CoM.

Hey, the personal ver. of program has been for 25 USD for the last 3-4 years ( how much did frames prices changed due to falling dollar ?!) which includes all future updates which is x times cheaper than standard FR stem and that little smart piece of code can provide information that NO manufacturer has ever provided. Correct me if I'm wrong . And author is willing to add new functionality AGAIN FOR FREE after some conversations are made.

 

[Honus]

Nobody can say the Linkage program is accurate or inaccurate because none of that is 100% true. Short link designs are not alpha-omega of the world and preset values like CoM can be easily modified if one knows the more correct position. The weakness of locating pivots on photos that are often distorted can be eliminated if you find allied person in manufacturers team who will give the correct positions or can be slightly supressed by taking a picture of bike from very long distance like 10m with camera pointed at frame's geometrical CoM.

The problem isn't so much the program and how it calculates values. The problem is the accuracy of data input- it's GIGO (garbage in, garbage out.) No model built on a photo reference will be accurate enough and short link bikes are the worst example due to how accuracy affects the outcome. It's simply useless to compare numbers unless you have personally measured a given frame design with a great degree of accuracy. CoM is even more difficult to place (with regard to real world application), making matters worse. Position of CoM may affect one design much more than another. It's always going to be a guessing game in using Linkage as an analysis tool. You have to back it up with actual data in order to get accurate comparisons, which requires you having access to the bikes you're trying to compare.

If I had someone sitting on a DW Link bike and I gave two separate people a tape measure, a dial caliper, a level, a protractor and a set of scales and told them to give me anti-squat calculations I'd bet dollars to doughnuts I would get two completely different sets of data- both of which you could throw out the window in terms of accuracy.

Unless you are building a design from scratch, Linkage is only useful in terms of generalities for the sake of comparisons.

 

[rbx]

Been discussed, it's been done - a little-known system referred to as "dw-link". Already explained how it works.


But the DW link doesnt seem to tapper off AS after sag it seems to stay around 100% up to the end.(i know i am relying on the linkgae program)

And if the dw link stay at 100% after AS then a "front the of bb" single pivot placed at the right place will act the same as the DW-LINK.
But the SP will have less active braking, but if you now add a floater then the superority of the dw link doesnt hold anymore.(again my humble observations)

 

[Kamanchi]

Does the Specialized Demo have good or bad anti-squat?

 

[time-bomb]

Does the Specialized Demo have good or bad anti-squat?

It has pro-squat. It has no angst for squat.

 

[Pslide]

Reviving this thread because of something I've noticed with my current and previous Banshee Legends that's relevant to the original post - the Legend pedals noticeably better with a 300lbs/in spring than a 350 (with me @ 200lbs aboard, 37t ring). With the 350lbs/in spring and about 30% sag, the suspension actually extends during each pedal stroke, which creates a noticeable amount of bob and the feeling that each pedal stroke is somehow levering the back of the bike up. With the 300lbs/in spring giving about 35% sag, the anti-squat has decreased significantly and the bike actually pedals much better - very little noticeable bob and no real sense that the bike is just folding itself in half instead of turning your efforts into speed.

If this bike had a constant amount of anti-squat even between say 25-40% travel, it'd have a wider range of potential setups before you started compromising pedalling performance. In my particular case this isn't a big deal because the sag/spring rate I want happen to coincide with the pedalling sweet spot (obviously because the bike was designed to pedal well at this particular point in the travel too), but some people like stiffer or softer setups that'd end up compromising the pedalling somewhat.

Socket, I'm assuming you're referring to your prototype Mk1?

According to the suspension curves from Keith, the production Mk2 has less anti-squat and should be less sensitive to sag position.

My Mk1 is also very sensitive, although I wouldn't say it bobs for me. The less sag I run, the better it accelerates. I run mine in the low 30s area. Have tried as much as 40% and it felt lethargic.

 

[Kamanchi]

Is pro-squat on the Demo good or bad for performance?

What pro-squat or anti-squat numbers stop you from winning a race?

 

[kickstand]

Moar importantly, how far beyond the sag is this rider......I noticed he isn't pedaling

You noticed he wasn't pedaling? I only see a still picture with Zero movement, I guess based on your conclusion that he isn't pedaling I could also conclude that he isn't moving either, or breathing, or maybe even riding or living at all.

 

[time-bomb]

Is pro-squat on the Demo good or bad for performance?

What pro-squat or anti-squat numbers stop you from winning a race?

You noticed he wasn't pedaling? I only see a still picture with Zero movement, I guess based on your conclusion that he isn't pedaling I could also conclude that he isn't moving either, or breathing, or maybe even riding or living at all.

Oh boy. Apparently my jokes are really bad, and also going right over the tops of several heads.

 

[Kamanchi]

Oh boy. Apparently my jokes are really bad, and also going right over the tops of several heads.

Ha ya I got it. I'm just bringing a point about the science of good and bad on this thread.

Does the Specialized demo have the wrong amount of anti-squat?

What are the squat/anti-squat numbers that will prevent you from winning a race?

 

[time-bomb]

Ha ya I got it. I'm just bringing a point about the science of good and bad on this thread.

Does the Specialized demo have the wrong amount of anti-squat?

What are the squat/anti-squat numbers that will prevent you from winning a race?

If you are asking me directly, the best I can do is lead you to the forest and then get you lost........and then leave you there to die a slow miserable death.

Is there a "wrong amount"? Is there such a thing? Some may argue yes but I would venture to guess there isn't a magical number out there that works for every bike or for every rider for that matter. It will depend on the bike design since they all have their own unique characteristics and like so many other things rider preference. Are there benefits to anti-squat, absolutely. How much should each bike have, depends on the bike. Will it cause you to win or lose a race, hell no. I can't believe there is one factor that is so almighty that it alone will determine that. Like most things, it is a variable in a long complex equation of things that all influence one another.

One thing is for sure though, if you learn how to ride well and pedal your ass off, that will help you win a race.

 

[Kamanchi]

Oh boy. Apparently my jokes are really bad, and also going right over the tops of several heads.

If you are asking me directly, the best I can do is lead you to the forest and then get you lost........and then leave you there to die a slow miserable death.

Is there a "wrong amount"? Is there such a thing? Some may argue yes but I would venture to guess there isn't a magical number out there that works for every bike or for every rider for that matter. It will depend on the bike design since they all have their own unique characteristics and like so many other things rider preference. Are there benefits to anti-squat, absolutely. How much should each bike have, depends on the bike. Will it cause you to win or lose a race, hell no. I can't believe there is one factor that is so almighty that it alone will determine that. Like most things, it is a variable in a long complex equation of things that all influence one another.

One thing is for sure though, if you learn how to ride well and pedal your ass off, that will help you win a race.

Thank you, that was an amazing answer and I agree with you. I enjoy how percentages are placed everywhere on here to show a positive but whats missing is what produces a negative. Are there numbers that someone can commit to and tell the world that they are absolute negatives?

It's why I bring up the Specialized Demo(FSR) and its weak anti-squat characteristics. Are you at an instant disadvantage for using a Demo considering the current "Anti-squat" marketing? Can you win a WC on a Demo?...of course.. so whats right? I have no idea

 

[Honus]

Thank you, that was an amazing answer and I agree with you. I enjoy how percentages are placed everywhere on here to show a positive but whats missing is what produces a negative. Are there numbers that someone can commit to and tell the world that they are absolute negatives?

It's why I bring up the Specialized Demo(FSR) and its weak anti-squat characteristics. Are you at an instant disadvantage for using a Demo considering the current "Anti-squat" marketing? Can you win a WC on a Demo?...of course.. so whats right? I have no idea

Anti-squat is just one performance aspect and it predominantly affects how a bike pedals. If you have a bike that has a lot of pro-squat then your suspension will have an obvious tendency to be mushy while pedaling. Some of this mushy feeling can be reduced by increased low speed compression damping (platform valving) at the expense of suspension compliance. The flip side to this is that too much anti-squat will cause the bike to bob while pedaling. It's a balancing act.

All suspension settings are a compromise between rider inputs (low speed) and bump inputs (high speed) and ideally what we want is a bike that has ideal anti-squat characteristics that allow us to more easily tune the suspension to minimize weight transfer during acceleration and braking while still having good bump compliance. By minimizing weight transfer you improve traction and you have a faster, more stable bike.

 

[Steve M]

But the DW link doesnt seem to tapper off AS after sag it seems to stay around 100% up to the end.(i know i am relying on the linkgae program)

And if the dw link stay at 100% after AS then a "front the of bb" single pivot placed at the right place will act the same as the DW-LINK.
But the SP will have less active braking, but if you now add a floater then the superority of the dw link doesnt hold anymore.(again my humble observations)

DW himself has stated that those values are rubbish, why try to base an argument or understanding on that?

Socket, I'm assuming you're referring to your prototype Mk1?

According to the suspension curves from Keith, the production Mk2 has less anti-squat and should be less sensitive to sag position.

My Mk1 is also very sensitive, although I wouldn't say it bobs for me. The less sag I run, the better it accelerates. I run mine in the low 30s area. Have tried as much as 40% and it felt lethargic.

I have both the Mk1 and Mk2 frames sitting here within arm's reach, and both the Mk1 and Mk2 simulation models from the online bike library in Linkage. It's fair to say that the Linkage models are more or less useless. Upper link fixed pivot for examples are within 2mm of each other on the actual frames (might even be identically placed) relative to the BB, yet in the models the vertical difference alone is 16mm.

As far as I know, the Mk2 has slightly less anti-squat (notice angles of the links are slightly different to the Mk1, as though the suspension is starting off a tiny bit more compressed) because as I said before, the Mk1 had too much - something I discussed with Keith for quite a while. IMO the Mk2 pedals better than the Mk1 (I run the same gearing ratios on both), though there is a distinctly noticeable difference between running circa 30% sag and ~35% sag, as there was with the Mk1.

 

[Pslide]

Thanks for the info Socket. I'm looking forward to getting my Mk2. I would also welcome your Mk2 review vs. Mk1 vs. Sunday vs whatever else you've had a chance to ride...

For what it's worth, I personally like that you can "tune" how you want the Legend to accelerate by adjusting your sag.

 

[Steve M]

Thanks for the info Socket. I'm looking forward to getting my Mk2. I would also welcome your Mk2 review vs. Mk1 vs. Sunday vs whatever else you've had a chance to ride...

For what it's worth, I personally like that you can "tune" how you want the Legend to accelerate by adjusting your sag.

Yeah the Mk2 is a much more refined bike than the Mk1 I think, as you'd expect - only thing I'm not sold on is that it's really, really long. My large Mk2 is at least 15mm longer than the Mk1, and that wasn't short. I'll get a tape measure onto it at some point. Bike park opens in a week, I'll get some setup time on it before I go giving out any reviews.

For what it's worth though, a bit of bobbing on a DH bike really isn't that big a deal in my eyes, as long as it's not really excessive. On an all-mountain/xc bike though I think efficiency is pretty critical.

 

[Slater]

Just for clarification I'm fully aware that the AS numbers I posted on the MK1 are not exact, and most likely a ways off.

However the point I was making stands, and Linkage supports your (Socket's) findings on the pedaling efficiency. You said with less sag and resulting higher AS, it seems to actually rise with each pedal stroke. Linkage confirms that it does indeed have relatively high AS, although we may not know exactly how much.