Ragley Full Suspension Prototype

Anonymous

Nope, the mondraker has no extra pivots, compared to if it had the same setup, but one ond of the shock was mounted on the frame. There's the pivots at each end of the links, and a pivot for each end of the shock.

bails87

Yes, I know, I was just pointing out that the Trek system pushes both ends of the shock, and has the same number of pivots as the FSR system, that only pushes one end. The quad link/Mondraker system chooses to have that extra link in between the chainstay and front triangle.

I might be wrong, I ride a HT, it's much easier!

joshtp

yeeha is right though... fundamentally most designs fall into just a few categories...

the most common deception is with single pivots... there are so many linkage, or even multi linkage driven designs given clever names that are, essentially just single pivot's...


I belive Felt's system is one of the unique ones though?

Anonymous

bails87 wrote:

Yes, I know, I was just pointing out that the Trek system pushes both ends of the shock, and has the same number of pivots as the FSR system, that only pushes one end. The quad link/Mondraker system chooses to have that extra link in between the chainstay and front triangle.

I might be wrong, I ride a HT, it's much easier!

Nope, it has no more pivots. It has the standard amount of pivots for an FSR.
Even the Marin has the same, even though the shock is tied to the ends of two of the links, there are still suspension linkage bearings, and then the shock's DU bushes between them.
One at each end of each link = 4 (taking a two dimensional side view for now to simplify designs that use needle roller bearings, giving one bearing for the width of a link)
One at each end of the shock = 2

total = 6 (for a VPP)

FSR = one at each end ot the shock = 2
Two on chainstay = 2
two on rocker = 2
Total = 6 (for an FSR)

Amazing, isn't it

Thewaylander

Indeed, I wasn't arguing over the different systems though, just the point the Mondraker has an extra pivot or two down the bottom to manage this sytem, Which it does and that has to be maintained. I know this as I have had to rebuild the buggers and there an arse to get to behind the cranks (Raceface getting rid of there handy self extracting crank bolt and me being to poor to buy a new Crank tool)

the rest of his point i have no idea who he is going on too the system on my 07 Stumpy FSR possibly had the most pivots of any bike i ever had to take too pieces.

Anonymous

No, there's SIX pivots. in a side on view.

bails87

yeehaamcgee wrote:

bails87 wrote:

Yes, I know, I was just pointing out that the Trek system pushes both ends of the shock, and has the same number of pivots as the FSR system, that only pushes one end. The quad link/Mondraker system chooses to have that extra link in between the chainstay and front triangle.

I might be wrong, I ride a HT, it's much easier!

Nope, it has no more pivots. It has the standard amount of pivots for an FSR.
Even the Marin has the same, even though the shock is tied to the ends of two of the links, there are still suspension linkage bearings, and then the shock's DU bushes between them.
One at each end of each link = 4 (taking a two dimensional side view for now to simplify designs that use needle roller bearings, giving one bearing for the width of a link)
One at each end of the shock = 2

total = 6 (for a VPP)

FSR = one at each end ot the shock = 2
Two on chainstay = 2
two on rocker = 2
Total = 6 (for an FSR)

Amazing, isn't it

My bad, I was looking at just the BB area of the Trek, where you're got one between the chainstay and frame, and one between the chainstay and shock. And then comparing that to the mondraker, where the lower link means an extra pivot.

But then with the Trek system there's a pivot at the axle, and three hanging off the link, so 6 in total again.

Thewaylander

And i was just talking about the BB area too like bails because we were discussing the solution of compressing the bottom of the shock.

All you have to is add specialized set up at the back fabout a zillion more ;p

bails87

Thewaylander wrote:

And i was just talking about the BB area too like bails because we were discussing the solution of compressing the bottom of the shock

But as the FSR vs ABP/Full floater comparison shows, compressing the shock from the bottom still only requires two pivots around the downtube/BB/chainstay area.

Anonymous

Erm, no! on FSR:

Behind BB,
on chainsteay in front of dropout,
On seatstay where it meets rocker
On rocker where it pivots
one on each end of shock.

SIX

Thewaylander

Yup Bails but Modraker use three or so, there is a link piece of metal with bearings at both ends and then the busshing sitting around the middle i believe. There are a million variations completing the same thing.

and with the servicing as i was trying to point out ( before yee goes off) these are low down, big mud eating bearings

supersonic

The mondraker, vpp, dw, maestro, ict, quad link, apb are all 4 bar linkages with 4 pivots. Put your shock in there and it uses and extra 2 pivots.

Anonymous

In fact, adding pivots will cause it to not work at all.

bails87

yeehaamcgee wrote:

Erm, no! on FSR:

Behind BB,
on chainsteay in front of dropout,
On seatstay where it meets rocker
On rocker where it pivots
one on each end of shock the one at the bottom of the shock.

SIX

Yep, I agree, and the ones I was talking about are underlined.

supersonic

Now the felt equilink... That is Stephenson six bar.

Anonymous

supersonic wrote:

Now the felt equilink... That is Stephenson six bar.

Ah, that's the other one I was trying to remember. I remember seeing a few things about it a while ago, but I can;t remember specifics.
Isn't that a Dave Weagle design?

Anyway, I'd actually go so far as to say that FSR and VPP are the same thing. It's just the length of the links that seperates them.

Anonymous

incidentally...
The Felt


Now that Is a lot of pivots!

pastey_boy

heres one from the pages of history

bails87

yeehaamcgee wrote:

incidentally...
The Felt
[Img snip!]Now that Is a lot of pivots! [/img]

Hmmm, so it's like a VPP type system, but with the red bar to keep the distance between the two links the same?

Why?! :?

supersonic

The system has multiple instant centres of rotation... But a set migration of the virtual pivot point (for the axle), like any other 4 bar. So the equilink doesn't do anything that cannot be achieved with a 4 bar in terms of axle path, anti squat and leverage ratios.