Mountain Biking - Suspension Design and Theory - Ripped from Trek thread

So let see....the more popular brands mostly from memory

Trek / Gary Fisher = Single pivot
Raleigh / Diamondback = Single Pivot
Cannondale = Single Pivot
Kona = Single Pivot
KHS = Single Pivot
Mountain Cycle = Single Pivot
Santa Cruz = Single Pivot (Super Light & Heckler)
Transition = Single Pivot
Turner = Single Pivot (Pre-2006 = Horst)
Jamis = Single Pivot (Pre 2004 = Horst)
Yeti = Single Pivot
Ventana = Single Pivot (thanks nav)


Devinci = Horst in Canada (in the USA = Sigle Pivot)
Giant = Maestro (Pre Maestro = Single Pivot) ( except NRS = Horst) thanks phoebeisis
Ellsworth = Horst (Except Isis, Joker, Distance = Single Pivot)
Iron Horse = DW Link (except Yakuza = Single Pivot) thanks KonaRider24
Intense = VPP
Mongoose / GT = Free Drive / iDrive (system is a different type of SP but maybe a SP )
Norco = Horst
Specialized = Horst
Santa Cruz = VPP (Blur, Nomad, VP Free, V10 (I think)
Titus = Horst
Rocky Mountain = ETSX (Others = Single Pivot)
Marin = Quad Link


The only thing I really dislike abount SP is that the suspension is not very active under braking situations. (Brake Jack /Squat) Also, depending on thier design, pedal feedback is more apparent in SP designs than most other systems. Pedal bob is also more in SP designs and they've become dependent on a platform shock for better pedaling these days. This results in a loss of small bump reaction. The rocker link designs help reduce this effect by increasing the leverage ratios.

Single pivots are nice becasue they are simple to maintain and are ideal for muddy riding conditions.
I've had to change the bushings on my Enduro after every season becasue of the play it eventually develops.

Correct - depending on pivot location the bike will squat or jack under braking conditions. This can be fixed by an aftermarket product that allows suspension to remain active when braking.

They other thing with single pivots, in general, is a catch 22. If you want no pedal bob you end up with a faily inactive suspension design. If you want active suspension you invariably end up with pedal bob. Horst and VPP remain active but reduce pedal bob.

Since we are making a list

gt-idrive is single pivot.
Devinci in canada is horst and in the states is sp

Correct - depending on pivot location the bike will squat or jack under braking conditions. This can be fixed by an aftermarket product that allows suspension to remain active when braking.


Ahh... right, your talking about a floating brake kit. If anyone is considering one, I don't ride with anyone that uses one so I do not have first hand information but through the grape vine, I've heard that it works quite well. However, these units are not compatable with all frame design.

Here is a review from another site.
http://www.nsmb.com/gear/therapy_02_05.php

Hey Maelstrom,
I forgot that Devinci had Hoerst licensing issues in the US. Thanks for clearing that up.

T.J.

To bad these posts are stuck in this thread. It could be useful information for someone and it is left in a thread most people won't come into :D...

Floating brakes varry depending on frame design. I would say most of the time they work well. On the two bikes I have used/seen them they worked like a charm.

Are the Giant NRS all considered single pivot?The swingarm pivots around 2 sets of fixed pivots,and it has 5 sets of bushings on each side.It works pretty well-of course you give up downward suspension movement(gradual dips-huge dips won't matter),but bumps are probably a bigger deal.I set it up to allow a tiny bit of bob;it is a lot less stiff that way.An aftermarket link to increase travel improved it in that respect also.Depending on how you pedal,you might regain most of the force-energy use to bob-you will lose the friction energy of course..
I would appreciate a web address to something that describes single pivot etc.Thanks.Charlie.

The Giant NRS was the exception. Good catch. Giant licenced Horst from Specialized for this bike.
http://www.giant-bicycle.com/us/050.000.000/050.500.050.asp

Last paragraph in the above article.
"Some elements of the NRS frame design were licensed from SPECIALIZED® and relate to the FSR Suspension Design U.S. patents 5,509,679/5,678,837/5,899,480"

Here is a good article that explains, in general, suspension history / designs.
http://www.whatmtb.com/workshopdetails.asp?id=24

T.J.

Edit; The last NRS made was in 04. It was replace by the Trance and now the even lighter Anthem

www.ridemonkey.com do some searches for posts by dw. He designed the dw link and is an amazing resource of information. There is a booksworth of information in his posts on that site. Thats where I got most of my information.

I can't find much else information. I highly recommend the ridemonkey search. Will take some leg work on your part but it will go into much better detail than most sites. You could search on this site too. I have covered this a lot and there might be some links I have put out in the past in regards to this.


NEat I didn't know nrs was horst now. I remember that being a regular rocker bar.

So let see....the more popular brands mostly from memory
........................
Kona = Single Pivot
......................................
Ellsworth = Hoerst (Except ID, Joker, Distance = Single Pivot)


Ok... i think i know nothing about suspension designs. I thought i knew what single pivot was until i read the statement above.

Horst:
http://www.ellsworthbikes.com/bikes/truth/img_truth/ellsworth_truth_blue_large.jpg

Single Pivot?
http://www.harfa-harryson.com.pl/sklep/kona/2K5_Dawg_Side-xl.jpg


To me, these two suspension designs look almost the exact same. Can anybody put up some diagrams explaining the difference?

I don't have any diagrams, but the difference is the pivot point by the rear axel. If the pivot is on the chain stay then it's considered a four bar suspension, most of which are Horst links. In Ellsworth's case they call it ICT. The Kona has the pivot on the seat stay which makes it a faux-bar/single pivot.

Dean

So those couple of inches in pivot location make a massive difference on how the bike handles while pedaling/braking?

And even still, i dont understand while its called single pivot when it pivots in multiple locations.

BEcause it acts like a single pivot.

And yes, that small change in pivot location makes a big difference. If you really want to know why go to ridemonkey and search for posts by DW. He goes into vey VERY extensive details about vpp, dw-link, fsr and single pivots.

Cheers Mael, i think i'll do that.

It relates to how the axle travels through the travel.

Here are some quick links to help explain. I am no expert, not an engineer, I just read through posts and articles

http://www.ridemonkey.com/forums/showthread.php?t=140919&highlight=suspension
http://www.ridemonkey.com/forums/showthread.php?t=92828&highlight=vpp
http://www.ridemonkey.com/forums/showthread.php?t=19653&highlight=vpp

Long thread covering brake therapy and brake jack etc..
http://www.ridemonkey.com/forums/showthread.php?t=141091&highlight=vpp
http://www.ridemonkey.com/forums/showthread.php?t=83379&highlight=fsr

Not exactly on topic but there is some discussion in there about single pivots etc..
http://www.ridemonkey.com/forums/showthread.php?t=126069&highlight=suspension

There I did some searching, enjoy the read. There are more articles in the archives. If you want to keep searching dw and zedbra kick ass in the suspension department :)

Treks Suck!!

Here is another link (from Specialized's site) that goes through all of the types with very well-done animated diagrams of each type. I KNEW I'd seen this a while back and forgot where it was. I finally found it:

http://www.specialized.com/sbc4Bar.jsp?a=b

And, yes, it's got a lot of FSR propoganda tilt; but the pictures and descriptions are good references.

It relates to how the axle travels through the travel.

Here are some quick links to help explain. I am no expert, not an engineer, I just read through posts and articles

http://www.ridemonkey.com/forums/showthread.php?t=140919&highlight=suspension
http://www.ridemonkey.com/forums/showthread.php?t=92828&highlight=vpp
http://www.ridemonkey.com/forums/showthread.php?t=19653&highlight=vpp

Long thread covering brake therapy and brake jack etc..
http://www.ridemonkey.com/forums/showthread.php?t=141091&highlight=vpp
http://www.ridemonkey.com/forums/showthread.php?t=83379&highlight=fsr

Not exactly on topic but there is some discussion in there about single pivots etc..
http://www.ridemonkey.com/forums/showthread.php?t=126069&highlight=suspension

There I did some searching, enjoy the read. There are more articles in the archives. If you want to keep searching dw and zedbra kick ass in the suspension department :)

wow, thanks a lot Mael.

I went looking for that. Couldn't find it to save my life. Stupid new specialized site.

Keep in mind those graphics, while good for reference, are flavoured towards the fsr design.

Thanks dminor

I went looking for that. Couldn't find it to save my life. Stupid new specialized site.

Keep in mind those graphics, while good for reference, are flavoured towards the fsr design.

Thanks dminor My Google engine was a quart low after I wrung it out looking :)

free_pizza, here's my attempt at explanation. (http://www.bikeforums.net/showpost.php?p=1679344&postcount=3)

Someone needs to do some homework if they think that the Id is a single pivot.



http://www.paradigmhosting.net/images/id.jpg

And when did Horst Leitner change the spelling of his first name?

The Horst link (pivot on the chainstay) yields the most vertical axle path of any major suspension design to date. This limits chain growth during suspension movement and effectively isolates the suspension from braking forces (aka brake jack).

The pivot on the seatstay yields an axle path that describes an arc with a radius equal to the chainstay length...essentially, it has the same characteristics of any single pivot design. The chain tension caused by pedaling will produce more bobbing, although a shock with platform damping will help significantly. Brake jack is present, but not as noticiable on shorter travel frames. Take a look at the longer travel single pivots (e.g. Kona Stab, Foes Mono) and you will see they use a floating caliper mount to mitigate the effects of brake jack. gastro made excellent points here. Because of these facts , the list of frames to replace my 19" 2003 Jamis Dakar is very short . A custom 20.25 " Titus Moto-Lite with a 69.5 degree head angle , is the only bike on the list.

Someone needs to do some homework if they think that the Id is a single pivot.
And when did Horst Leitner change the spelling of his first name?

Doh! http://i25.photobucket.com/albums/c76/TequilaJoe888/Junk/pat.gif I meant ISIS. Now I have to go and edit all my replies. http://i25.photobucket.com/albums/c76/TequilaJoe888/Junk/eek3.gif
Thanks for the catch.

T.J.

whatever, only one mistake, impressive that you got all the rest from memory, thanks for posting this!

So those couple of inches in pivot location make a massive difference on how the bike handles while pedaling/braking?

And even still, i dont understand while its called single pivot when it pivots in multiple locations.

i have often wondered that too. although i dont know much about suspension designs etc, so someone please correct me if i am wrong, but from what i just read i think basically the pivot location refers to the pivot of the swingarm. that is the arc around which the rear wheel will move under bump force or whatever. like i just read somewhere: the basic intention of both front and rear suspension designs are to isolate the wheels from the rest of the bike. i guess to allow a path for the wheel to move under bumping etc in such a way that only the wheel responds to that bump, and when the wheel moves to absorb the hit, there is no, or atleast not much or a minimum, amount of force travelling into the frame itself, or force travelling outside the wheel. basically that is what most designs try to maximise i think, to try contain the force that hitting a bump creates within the wheel...?

eh. does that sound about right?

so i think the pivot location with single vs multi pivot designs etc refer to the number of pivots around which the feel finds an arc to move under bumping. so if there are a number of pivots for linkages for shocks etc, that doesnt matter, if there is only one pivot that allows movement of the wheel then the bike is a single pivot bike. if the arc along which the bike will move has been created by more than one pivot, well then thats not a single pivot bike.

okay, if ive just been talking crap or something someone please let me know, this stuff is all interesting but frankly i dont get a lot of the physics when i read the "experts" at ridemonkey or mtbr. so it would be nice if someone could babylanguage it for people like me. thanks!!

My attempt at baby language. :)

Think of it this way. Hold out your hand, palms up. Make a fist. The plane of the palm of your hand represents the rear axel. Rotate your elbow up and down about 5" but do NOT bend your wrist. You elbow is the pivot point on the frame and your fist/rear axel travels in an arc. This is a single pivot.

Now do the same thing but you are now allowed to bend your wist. As you rotate you elbow up, bend your wrist back. This is Horst. It is more active and as you bend your wrist back, you can make your fist travel vertically.

T.J.

This is my simple explanation. Don't get me started on DW Link, VPP and Quad Link cause I do not think any body part can similate it! :D

My attempt at baby language. :)

Think of it this way. Hold out your hand, palms up. Make a fist. The plane of the palm of your hand represents the rear axel. Rotate your elbow up and down about 5" but do NOT bend your wrist. You elbow is the pivot point on the frame and your fist/rear axel travels in an arc. This is a single pivot.

Now do the same thing but you are now allowed to bend your wist. As you rotate you elbow up, bend your wrist back. This is Horst. It is more active and as you bend your wrist back, you can make your fist travel vertically.

T.J.

This is my simple explanation. Don't get me started on DW Link, VPP and Quad Link cause I do not think any body part can similate it! :D

oh, actually that is pretty good! the damn fist does move vertically if you bend the wrist backwards! well, whaddya know! man, i wish i had you as my physics instructor back in school :D

thanks man. i read a little bit more here and there, and the single pivot is easy enough to understand, as is the bit you just very eloquently demonstrated, basically the fundamentals of what a rear suspension "should" do is simple enough but man i just cannot comprehend all those imaginary arcs and virtual pivots and all. when i am ready to buy a fully ill just come here and say this is my budget, this my riding, these my preferences, now suggest, suckers!! :D:D just kidding.

I see.If you freeze the pivot on a single pivot,the rear triangle-axle won't move-all the pivots will freeze.However on a dual pivot-you can freeze one pivot,but the axle can still move around the other.Thanks.Charlie

This is my simple explanation. Don't get me started on DW Link, VPP and Quad Link cause I do not think any body part can similate it! :D

Actually your description applies, except its like having two arms instead of one, while also having a small verticle plain to move up and down ;)...

Brilliant descriptiong btw

The non-Horst four bar could be refered to as a linkage-driven single pivot. Look at the Astrix Solo or Monk (which actually have a real design and reason behind the extra linkage), it's kind-of doing the same thing (using pivots to redirect the force of compression), but not in a four bar styling.


Ventana = Horst
Ventana uses a non-Horst faux bar design. To great success, might I add.


Rocky Mountain = ETSX (Others = Single Pivot)
The ETSX is so much like a weird Horst link that I'm suprised no one says much about it.

Banshee, Haro, and Cove are all coming out with VPP/DW-inspired "short link four bar" designs. I do find the Haro Sonix design to be very interesting, but I don't know if it'll work or if I'd want to own one (especially considering the bottom bracket pivot).

Ya I just noticed that on the banshee site. I am quite excited by the prospect of that bike with vpp. It always pedals surprisingly well.

Iron Horse should be in both categories.

The Yakuza line is Single Pivot.

Ventana uses a non-Horst faux bar design. To great success, might I add.


Really? http://i25.photobucket.com/albums/c76/TequilaJoe888/Junk/pat.gif My memory seems to be failing me. http://i25.photobucket.com/albums/c76/TequilaJoe888/Junk/fagdiaf.gif
Thanks for catching this one. I'll fix the original post so there isn't any confusion.

T.J.

So is there a concensus on which system is best?

From what i understand (which is very little) the dw-link seems to work the best? Or is it a matter of preference, shock choice, amount of travel, intended use, and riding style?

Depends on what "working best" means to you. I find fsr adequate but in the same breath it doesn't feel active. Overall after years of riding I can say I like the rocker style 4bar for active and decent suspension. Dw link is catching on as is vpp but with vpp there are complaints of poor performance on the small bumps. Again thats the comprimize for having an excellent pedalling machine. So

Its a matter of
1 - design
2 - usage and rider
3 - design + shock (for example Avy is an amazing shock on a single pivot but is pointless on an fsr)

Or is it a matter of preference, shock choice, amount of travel, intended use, and riding style?I think that about sums it up. Throw into that everyone's prejudices, rabid loyalties, justified as well as uninformed loathings and you get all these different approaches to the "ideal setup."

Or is it a matter of preference, shock choice, amount of travel, intended use, and riding style?


exactly. throw budget into the mix as well. that and fit, and whichever feels good to you when riding it.

Heh fair enough.

It wouldnt be mtn biking if it wasn't vauge as hell when it comes to equipment choice :D

Heh fair enough.

It wouldnt be mtn biking if it wasn't vauge as hell when it comes to equipment choice :D

At least its all expensive...thats the only thing that seems to stay equal...

At least its all expensive...thats the only thing that seems to stay equal...

No doubt!

OK, there needs to be some clarification here. A bike with a dropout pivot above the dropout is NOT a single pivot, and it does not act like one.

If you look simply, you might think that it is single pivot because the axle rotates on a single path around the main pivot, but what is not being taken into account is shock compression rates. There is a lot more to suspension design than just axle path. 4 bar linkages change the shock compression rate throughout the stroke, allowing the designer to adjust the feel of compression throughout the stroke.

Single pivots drive the shock directly with the swingarm. The difference here is that with a 4-bar, you can work to tune out some of the unwanted suspension action, so they are great for XC and trail, and a single pivot is much smoother throughout the stroke, so better for big hits, but is much harder to tune out unwanted feedback unless you run an SPV or similar shock.

The original statement of this thread is wrong by looking at suspension systems too simply. There is a drastic difference between Horst and 4-bar, namely the dropout alignment which allows for better pedal feedback, and then there is an even larger difference between the two of them and true single pivots.
VPP, DW, Quad Link are all 4-bar systems that have been modified with shorter links. One good thing that came out of Specialized's patent greed is that these systems were able to flourish, while they might not have come out if everyone could have just stolen Horst links without paying Specialized.

here is the list, amended to take into account all aspects of the suspension system.

Trek / Gary Fisher = Fuel/Sugar/EX = Pivotless 4-bar Cake= Single Pivot
Raleigh / Diamondback = 4 bar
Cannondale = Rush/Prophet = Single Pivot Scalpel= pivotless 4 bar
Kona = 4 bar
KHS = 4 bar
Mountain Cycle = Single Pivot
Santa Cruz = Single Pivot (Super Light & Heckler)
Transition = 4 bar
Turner = 4 bar (Pre-2006 = Horst)
Jamis = 4 bar (Pre 2004 = Horst)
Yeti = pivotless 4 bar
Ventana = 4 bar
Devinci = Horst in Canada (in the USA = 4 bar)
Giant = Maestro-4 bar NRS-Horst AC-4 bar
Ellsworth = Horst (Except Isis, Joker, Distance = Single Pivot)
Iron Horse = DW Link (short 4 bar) (except Yakuza = Single Pivot)
Intense = VPP (short 4-bar)
Mongoose / GT = Single pivot with floating BB
Norco = Horst
Specialized = Horst
Santa Cruz = VPP (all short 4-bar) (Blur, Nomad, VP Free, V10 (I think)
Titus = Horst
Rocky Mountain = ETSX (ETSX is a Horst with an elevated chainstay) (Others = Single Pivot)
Marin = short 4-bar

By patent, a Horst is a 4 bar link where the dropout is an integral part of the seatstay. The ETSX is very close to violating the Horst patent, and if you wanted to stretch, most of the short link 4 bar systems have the dropout as an integral part of the seatstay, so they could go that far, but it would be a hard one.

Now, it was said that the 4-bar non-horst bikes were single pivots. Part of the discussion was about braking. Without the actual Horst pivot, it is possible for these bikes to stiffen up and act more like single pivots under hard braking. HOWEVER, it is not simple enough to just call them single pivots because for the rest of the time, they do not act like single pivots.

Also, there was some talk about Single Pivots being easier to maintain. This is not entirely true unless it was designed well. There are more bearings in a 4-bar, but there is less stress on each bearing and thus they will last longer. For instance, my Prophet used two bearings the same size as Ellsworth uses in their Horst bikes. That was the entire pivot. The bike was very wiggy and the bearings went fast. Ellsworth uses a much larger bearing on their single pivot bikes thus the stress is matched with proper amount of bearing. So maintainence is more dependent on proper engineering of the pivots.

I would love to see you in a discussion with dw, I think it could be a good e-fight. Personally I am not versed enough to debate with you the points that you are disagreeing with me about. I will comment on a couple of points.



The original statement of this thread is wrong by looking at suspension systems too simply


You are kind of coming in after the fact. This discussion started in another thread and I pulled it out of that thread. There was no clear "first" post. Thats why the thread seems to start kind of oddly.



The ETSX is very close to violating the Horst patent, and if you wanted to stretch, most of the short link 4 bar systems have the dropout as an integral part of the seatstay, so they could go that far, but it would be a hard one.


Gotta love canada. We dont have to obey american patents. There have been a couple of companies to have horst 4bars in their fleet for canada :)



Also, there was some talk about Single Pivots being easier to maintain. This is not entirely true unless it was designed well. There are more bearings in a 4-bar, but there is less stress on each bearing and thus they will last longer. For instance, my Prophet used two bearings the same size as Ellsworth uses in their Horst bikes. That was the entire pivot. The bike was very wiggy and the bearings went fast. Ellsworth uses a much larger bearing on their single pivot bikes thus the stress is matched with proper amount of bearing. So maintainence is more dependent on proper engineering of the pivots.


I would agree, I never bought into the single pivots are more durable talk.

I would agree, I never bought into the single pivots are more durable talk.There is a degree of validity to it, though, because of the way single pivot is usually executed. When the design depends on a single pivot, the mfr quite often relies on a set of pretty hefty bearings to carry the load. Comparatively, Specialized with the FSRs tend to use kinda small sealed ball bearings. They are fairly low-grade off-the-shelf industrial ball bearings that are really intended for use in rotating machinery - - not for the type of loads a bicycle suspension subjects them to. Designs like that would be much better served by a sealed needle or roller bearing setup, but it's much cheaper to buy stock ball bearings, so that's what you end up with: undersized bearings that fail after a season or two of hard use.