For all the suspension geeks out there (mainly for Socket)

[Ryan]

Here's a pretty good look at the '04 Specialised 6-bar link bike
http://www.farkin.net/forums/album_pic.php?pic_id=197
Personally, I don't get it. Looks kind of like a simple swingarm with a walking beam tacked on to it though what this achieves is beyond me so maybe someone else can come up with an explanation.
The pic was taken from the ridemonkey forums, but originally comes from GoHuckYourself.com (http://www.gohuckyourself.com), so a big thank you to them for the spy shots.

[josh]

all those bars are confusing

[frank-oi]

i think that it's workin in the opposite way to a giant DH. but then again im not to sure. and i don't thnk that i can explaine it.

complex

[kalem]

It looks like a single pivot, except it's attached to that top section, which would change the wheel path, braking etc. Need to see what's behind his foot i reckon...

[wombat]

Need to see what's behind his foot i reckon...
That's what I was thinking.

[S.]

Need to see what's behind his foot i reckon...

No ya don't, it's still an FSR link bike, cept now the shock is mounted from the chainstays instead of the upper link. You can see all the pivots.

[Ty]

um, i can't see any piviot near the BB for the chainstay to be attatched to. it almost looks like a URT (maybe the piviot is behind his foot)? or maybe it's like the maveric mono link or what ever?

[S.]

?? The BB-area pivot is about 1" above the BB... I think it's just due to a blurry pic that you can't see the defined chainstay (I'm 99% sure the BB is on the front triangle).

[Ryan]

If you think of the whole "inner swingarm" part as just a modified chainstay, then Socket's theory makes sense, just a 4 bar with the shock mounted on the chainstays. There's a pivot right above the BB, so it looks like maybe a URT?

[Ghost]

That's fairly interesting, though I'm a little concerned about the four pivots surrounding the rear hub. Having them in line is likely to cause a lot of stress.

The bike also looks to be pretty heavy. I'd need to ride one before I could comment on anything else.

[Gutty]

It's not a URT, you can see the pivot just above the BB, a URT usually has the pivot just in front of the BB. I agree with Socket, it's just a standard FSR design but the shock is driven by the chainstay much like a normal single pivot(222, bullit etc). Note the shock angle, to keep it some what progressive i assume ??
I really don't see the point of it though, other than getting the shock a bit lower(ok alot lower) i don't see what it achives.

Edit: It does look to have very good standover clearance. maybe thats one reason for the design change.

[Gutty]

That's fairly interesting, though I'm a little concerned about the four pivots surrounding the rear hub. Having them in line is likely to cause a lot of stress.



Huh ? i only see 1 pivot at the back end(well 1 per side) just like a normal FSR. The furthest one back is the axle. :idea:

[S.]

That's fairly interesting, though I'm a little concerned about the four pivots surrounding the rear hub. Having them in line is likely to cause a lot of stress.

The bike also looks to be pretty heavy. I'd need to ride one before I could comment on anything else.

Intenses also look very heavy... looks can be deceiving.

[Ghost]

That's fairly interesting, though I'm a little concerned about the four pivots surrounding the rear hub. Having them in line is likely to cause a lot of stress.



Huh ? i only see 1 pivot at the back end(well 1 per side) just like a normal FSR. The furthest one back is the axle. :idea:

*Drinks stiff coffee and checks again*

Crap. :(

Well, that's what you get for taking a quick glance and replying.

It still looks heavy though... 8)

[MrPlow]

Looks to me like a parallelogram almost. The top arm is just further forward than the bottom arm. Would allow them to place the top arm so low cause of the tyre clearance? (am I making sense?). the shock arm has a nice rising rate to it as well as being placed low in the frame, I personally don't like the orientation of the shock (shaft to top) as crap can get stuck there, not to mention the wheel driving mud into it. Turn it around I say, if those top and bottom arms are unequal (chances are) it would more likely create a virtual pivot point way the buggery out the front of the bike, I like VPP's, mmmmmmm, V10!!!!!!!

[S.]

Looks to me like a parallelogram almost. The top arm is just further forward than the bottom arm. Would allow them to place the top arm so low cause of the tyre clearance? (am I making sense?). the shock arm has a nice rising rate to it as well as being placed low in the frame, I personally don't like the orientation of the shock (shaft to top) as crap can get stuck there, not to mention the wheel driving mud into it. Turn it around I say, if those top and bottom arms are unequal (chances are) it would more likely create a virtual pivot point way the buggery out the front of the bike, I like VPP's, mmmmmmm, V10!!!!!!!

It won't have a virtual pivot point/centre of curvature way out in front of the bike. The near-parallelogram you refer to won't project a VPP/CC out in front of the bike, that's the IC (instant centre) which affects braking rather than axle path.

You also can't tell what kind of rate you're going to get (although it's a fairly safe assumption that it's a rising rate) just from the angle of the shock there. Turners (the 02 and older ones) look like they have a rising rate all the way, in actual fact they have a falling rate which progresses into a rising rate.

[trobb]

That looks pretty confusing but then i know, ive never seen one. If it does the job than im happy, i might be getting one of those bikes yayyyyyyyy!!!

[frank-oi]

nope change my mind it look like a prototype bike to me of no specific style or like anything else. nice.

[CHEWY]

http://www.farkin.net/forums/albums/714.jpg

thats basically it

[frank-oi]

yep thats it.hav to wait to see how it goes tho.

[S.]

I'd say somebody on one of the forums just sketched that themselves, because if you look closely the upper link is way too short and the pivot near the BB is too far up and forward in the diagram.

[Ty]

well, what ever suspension design it is (4 bar, 6 bar, vpp) i'm glad to see a 26 inch rear wheel is now a option

[MrPlow]

Socket, are you telling me you cannot make a four bar linkage scribe a virtual fulcrum arc (or close to one) by creating them with unequal angles? Comon, I am sure you could! Stuff around for a bit on CAD (Solidworks is the go for that stuff) and see what u come up with. That sketch is way outta scale to!
And I would bet my left testicle that as that swing arm compressed the shock up to 90 degrees it would be rising rate too :wink:
Still think that shock orientation is just begging to changed, seals would suffer in that position for sure??

[S.]

Define "virtual fulcrum arc". If you mean projected centre of curvature (ie not real as in a singlepivot) then yes. However, I can tell you now that the CC is not in front of the bike.

With proper linkage (ie not linkage-activated singlepivots) bikes, unless you happen to have an equation modelling the situation, you really need to plot it out to be able to determine the rate. Just because the swingarm - shock mount - shock fix pivot reaches 90 degrees (which you don't know that it does anyway) doesn't necessarily mean that it's a rising rate. Look at a lot of 4-bar bikes, the shock link goes past 90 degrees with the shock and yet the rate is still rising. I'm fairly sure this bike WOULD however have a rising rate just because Specialized DH bikes typically do and it makes sense for the application. Have you actually modelled the situation in any way? If not, then you can't make any claims on the rate.

Shock orientation isn't that bad, I don't think it's any worse than the current crop of 4-bar bikes.

[MrPlow]

Socket I am not claiming to be some sort of Guru of linkages mountain bikes! I am also not proffessing to know more than you or anybody else. That is why I tried to use "I personally" and "more likely" and "looks to me". I have however done a lot of geometry (as I am sure you have too) and am merely trying to apply this to the thread. Sorry if Iam taking your response the wrong way, but you seem pretty harsh. Of course I have not modelled this linkage, where would I possibly gather the information?? I still think shock orientation is not optimum though, do you see why I say that? I know mtb dsign is not my field of expertise, but in my industry nobody in their right mind would ever place a ram or telescoping device "upside down" why should mtb's be any different? This is not intended to degrade your own opinion, I am just expressing mine and asking for a response. You sound like a smart fella, lets pull this thing down and share some knowledge :!: :D :D :D
"Virtual fulcrum arc" is a projected centre of curvature.
How do you know this is not out the front of the bike?
Please define your perception of rising rate?

[Ghost]

well, what ever suspension design it is (4 bar, 6 bar, vpp) i'm glad to see a 26 inch rear wheel is now a option

Damn right, the 24" as standard was a massive deterrent for me. I probably would've bought a '03 BigHit otherwise.

[S.]

Socket I am not claiming to be some sort of Guru of linkages mountain bikes! I am also not proffessing to know more than you or anybody else. That is why I tried to use "I personally" and "more likely" and "looks to me". I have however done a lot of geometry (as I am sure you have too) and am merely trying to apply this to the thread. Sorry if Iam taking your response the wrong way, but you seem pretty harsh. Of course I have not modelled this linkage, where would I possibly gather the information?? I still think shock orientation is not optimum though, do you see why I say that? I know mtb dsign is not my field of expertise, but in my industry nobody in their right mind would ever place a ram or telescoping device "upside down" why should mtb's be any different? This is not intended to degrade your own opinion, I am just expressing mine and asking for a response. You sound like a smart fella, lets pull this thing down and share some knowledge :!: :D :D :D
"Virtual fulcrum arc" is a projected centre of curvature.
How do you know this is not out the front of the bike?
Please define your perception of rising rate?

Sorry if I sounded like I was trying to be nasty, I don't intend to offend anyone. And no, I'm not a suspension guru or anything either.

I understand why you think that the shock orientation isn't great in regards to mud and so on, but what's wrong with having it "upside down"? As far as mud/roost goes at least, it wouldn't be too difficult to rig a sheet of plastic or something as a mudguard.

I have actually done a very rough model of this system, and the CC is somewhere in the vicinity of the BB (just behind, moving towards the BB according to my model), and unless I'm drastically off in my estimations then it shouldn't change greatly. This is quite similar to most 4-bars so I have no reason to suspect that it's miles off.

A rising rate is where the instantaneous leverage ratio (axle movement vs shock movement) becomes lower as the bike moves through its travel. Eg if a bike has a 3.5:1 ratio at top-out and a 2.7:1 ratio at bottom-out, it has a rising rate. If it maintains a close to constant ratio throughout its travel (seeing as a perfectly constant one is technically impossible) it has a linear rate.

[MrPlow]

No worries Socket. sounds like this would be a logical place for the projected arc to be as this would remove pedalling interference with suspension movement? Yeh, no hard feelings! Sounds like you are pretty up with yer bike stuff though. Seeya later. :D

[S.]

It does pretty much allow you to pedal through nearly anything cos there's very little kickback, but they feel mushy as shit to pedal. I spose that doesn't matter so much now seeing as we have 5ths and Swingers and so on to make bikes pedal well.

[RaID]

looks a little different

dont really understand or see much point why the shock
is connected like this ie single pivot style

i guess the usual 4 bar linkage added on top
just prevents brake jack (sort of like a floating brake)
and changes the wheel path to be similar to the standard FSR linkage bikes

the wheel path would have to be modelled and like
Socket said the CC would have to be determined

hmmm so far i dont think im a fan, but hey if it works
well why should it matter

i guess its just gonna be hard to compare this linkage
to the standard FSR as you would need the same shocks in there to say which one is better

Id be interested how this rides and pedals with a standard Fox shock

[inlina]

No ya don't, it's still an FSR link bike, cept now the shock is mounted from the chainstays instead of the upper link. You can see all the pivots.

I must agree. It's just an FSR setup by the looks, just repackaged the shock set up to either move weight lower, change some geometry etc.

CG

[MrPlow]

Marketing gimmick or improvement? Always hard to tell the difference.

[S.]

Marketing gimmick or improvement? Always hard to tell the difference.

I'm guessing that it's a mild improvement, but its use as a marketing tool has already worked. Look at how many people are discussing it already.

[fastrider gus]

looks prety funky! about time they redesigned their bikes..

[bikeman_baldrik]

It's a lot simlper than it looks really, its a single pivot ( like the old cannondale super Vs) with a 4-bar coming off the chainstay/seatstay junction.
This would mean a hugely adjustable bike with all sorts of adjustable bits including travel, compression rate (rising, falling, linear), and heaps more, but it's gonna come at a price.

[fastrider gus]

is that the cannondale that the team was only riding for a while? i think thats the ones that ced and anne are riding in Dissorder 2? it does look very simmilar appart from the second shock hey..

[MrPlow]

I'm guessing that it's a mild improvement, but its use as a marketing tool has already worked. Look at how many people are discussing it already.
Too true! I don't think it is single pivot in geometry though is it ?

[wombat]

It's a lot simlper than it looks really, its a single pivot ( like the old cannondale super Vs) with a 4-bar coming off the chainstay/seatstay junction.
This would mean a hugely adjustable bike with all sorts of adjustable bits including travel, compression rate (rising, falling, linear), and heaps more, but it's gonna come at a price.

I think you'll find it's a 4bar linkage, not a single pivot. Look at the rear dropout, there is no solid link between the axle and the mainframe, (ie. the axle isn't mounted to the chainstay).

[S.]

It's a lot simlper than it looks really, its a single pivot ( like the old cannondale super Vs) with a 4-bar coming off the chainstay/seatstay junction.
This would mean a hugely adjustable bike with all sorts of adjustable bits including travel, compression rate (rising, falling, linear), and heaps more, but it's gonna come at a price.

I think you'll find it's a 4bar linkage, not a single pivot. Look at the rear dropout, there is no solid link between the axle and the mainframe, (ie. the axle isn't mounted to the chainstay).

Yep, this isn't a linkage actuated singlepivot (Kona, Giant AC etc), it's an actual FSR link bike.

[S.]

I'm guessing that it's a mild improvement, but its use as a marketing tool has already worked. Look at how many people are discussing it already.
Too true! I don't think it is single pivot in geometry though is it ?

I don't understand what you mean... do you mean axle path? Without a good side-on pic of it, I can't really tell.

[MrPlow]

I think you'll find it's a 4bar linkage, not a single pivot. Look at the rear dropout, there is no solid link between the axle and the mainframe, (ie. the axle isn't mounted to the chainstay).

Yep, this isn't a linkage actuated singlepivot (Kona, Giant AC etc), it's an actual FSR link bike.
you answered me here socket.