[biker3]

So after reading the new Dirt Ive been thinkin lots about single pivots and linkage. I know this has been beat into the ground but I don't remember seeing too much about moto stuff. Its strange to me that none of the moto companies have tried linkage and or floaters on the swingarms? According to the guy from Mojo "brake Jack" can be combated by riding the bike correctly and that suspension performance is more about the shock setup.

I understand a moto bike might have stiffness issues with linkage and since there arent pedals thats another thing but for sheer bump absorption why do moto's only use the standard single pivot swingarm designs?

Also regarding set up? That mojo guy thinks that ultra stiff, skippy sorta setups are the fastest? Im just having some trouble comprehending. Any thoughts would be cool.

Please no flaming.

 

[MikeD]

Not an engineer (obviously), but here's one thing to think about...a bicycle has pedals and feet, a relatively large amount of mass relative to the total mass of bike and rider, moving in big circles when pedalled. A moto has a relatively miniscule amount of mass to its total weight (a single piston) moving in a very short path back and forth...its suspension probably doesn't have to deal with the bob and feedback issues in the same way a mountain bike does.

But I'll shut up and listen to the smart people now.

MD

 

[motomike]

A MX bike is not a basic single pivot setup. Go look at one and you'll see under the swingarm that there is a good sized wishbone connecting the shock to the swingarm.

 

[motomike]

Oh and it pretty much HAS to be this way. Any other setup, like a chainstay/seatstay setup wouldn't work. There are major clearance issues with the number plates, subframe, airbox, silencer, etc. that anything else would hit. Especially with the new dual exhaust CRF coming out, it just wouldn't work.

 

[ncrider]

A MX bike is not a basic single pivot setup.

Wrong.

 

[speedster]

It simply comes down to a moto having a substantial, consistant power source for it's size. Humans cannot put out extra power to compensate for bob and other factors in a mountain bike. Mountain bikes have to be made efficiently because we have a limited power supply. Motos already have consistant power, no pedal bob so to speak, so they can concentrate on suspension travel.

 

[TWISTED]

A MX bike is not a basic single pivot setup. Go look at one and you'll see under the swingarm that there is a good sized wishbone connecting the shock to the swingarm.

KTMs have no linkage at all.

 

[motomike]

Wrong.

Yes I know. I was simply stating that the shock is not mounted directly to the swingarm. That, in my eyes, is a single pivot.


And who rides KTMs anyway. sheesh.

 

[ncrider]

I was simply stating that the shock is not mounted directly to the swingarm. That, in my eyes, is a single pivot.

Wow your lucky it's late cause people would rip on you for that statement.

Mountain Cycle Shockwave uses a very moto style setup and it is most def a single pivot.

There are numerous examples of single pivot designs that don't have the shock mounted to the swingarm. I'm no E-engineer but Shock mount location is not what makes a linkage type. It may be partial determined by linkage type, but it does not determine the type.

 

[bballe336]

Also regarding set up? That mojo guy thinks that ultra stiff, skippy sorta setups are the fastest? Im just having some trouble comprehending. Any thoughts would be cool.

Please no flaming.

well that is what HE FEELS fastest on. you might feel faster or be faster on a different type of bike. it is mostly an opinion he is forcing onto others. maybe he is fastest on a single pivot and you are fastest on a 4bar. its all opinion and rider preference.

 

[ncrider]

why do moto's only use the standard single pivot swingarm designs?

They are efficient, simple, easily maintained and strong. Also, having an engine in the center of the frame really dictates to where a linkage can be.

 

[thaflyinfatman]

Wow your lucky it's late cause people would rip on you for that statement.

Mountain Cycle Shockwave uses a very moto style setup and it is most def a single pivot.

There are numerous examples of single pivot designs that don't have the shock mounted to the swingarm. I'm no E-engineer but Shock mount location is not what makes a linkage type. It may be partial determined by linkage type, but it does not determine the type.

As far as shock actuation goes, there is a VAST difference between a straight singlepivot (no linkage) and one with a linkage to drive the shock (DHR, Shockwave, El Cuervo, Kona/Banshee etc etc). MOST motos don't use straight singlepivots, they use a linkage to drive the shock because that way they can get a progressive rate out of it. Not that you can't get a progressive rate from a shock alone, that's what KTM/Progressive/Manitou/Curnutt do, but given that Mojo are so blatantly anti-platform/progressive shocks, that seems to be somewhat contradictory. The reason that motos use "singlepivot" swingarms is because it's cheaper than making a full on linkage, provides less clearance problems, and because they simply don't need a complex suspension response to acceleration the way pushbikes do. Engines don't get tired or whinge if the bike is inefficient because it squats under acceleration (in fact I think they rely on it squatting quite a bit for traction), and they also have a low torque/high-rpm output that comes out as a VERY smooth output compared to 80kg of meat jumping up and down on the pedals - when was the last time you saw a motorbike "bob"? And as for braking, motos have a good 80kg of additional mass, 13" of travel, and 5" tyres to cope with brake "jack" (by which I presume you mean squat). I'm fairly sure floating brakes have been tried on motos anyway.

Long story short: stop comparing motorbikes to pushbikes, they require significantly different systems and setups.

 

[ncrider]

As far as shock actuation goes, there is a VAST difference between a straight singlepivot (no linkage) and one with a linkage to drive the shock

In the end, regardless of shock actuation they're still a single pivot design.

I agree with the rest of your moto lecture though. You left out rant off at the end. You were getting on a roll there.

 

[motomike]

In the end, regardless of shock actuation they're still a single pivot design.

 

[BigHit-Maniac]

We have legs... they have engines.

Enough said.

 

[manwithgun]

Suzuki had full floaters on their mx bikes during the 80's and KTM's are notorious for having the worst suspension.

 

[Percy]

Suzuki had full floaters on their mx bikes during the 80's and KTM's are notorious for having the worst suspension.

The Suzuki full-floater didnt refer to the brakes,it referred to the fact the shock wasn't attached directly to the frame,but was between the swingarm and the upper link,like that Tomac model I cant remember the name of right now.

KTM's dont have bad suspension,they're a bit tricky to set up,but work sweet when they are.

Oh and Brake Therapy do floating brakes for MX bikes,they do exactly the same things they do for MTB's.

 

[Ian Collins]

Wrong.

no....not wrong....it's a single pivot with a rate modifying linkage to be absolutely correct....

in moto there are two types:

single pivot without rate modifying linkage
single pivot with rate modifying linkage

in bikes there are three:

single pivot without rate modifying linkage
single pivot with rate modifying linkage
multiple pivots with axle path modifiers(both with and without rate modifiers)

 

[manwithgun]

The Suzuki full-floater didnt refer to the brakes,it referred to the fact the shock wasn't attached directly to the frame,but was between the swingarm and the upper link,like that Tomac model I cant remember the name of right now.

KTM's dont have bad suspension,they're a bit tricky to set up,but work sweet when they are.

Oh and Brake Therapy do floating brakes for MX bikes,they do exactly the same things they do for MTB's.

I stand corrected... looks like I'll need yer number to fact check my posts before clicking "submit reply". Just had a faint memory of being a kid and the term "Full Floater" seemed like magic. Wasn't it printed on the swingarm or something? And honda had the Pro-Link?

 

[dw]

Motocross bikes (with rider) have a much lower center of mass than a bicycle, and therefore, the single pivot arrangement is quite satisfactory on most for braking performance. The identical layout for a bicycle would have totally different effects under braking.

Dave

 

[shock]

Motocross rear suspension is sooo affected by braking force. Watch an outdoor national or gp, and see how the riders are getting hammered in the braking bumps. Especially the way a moto track develops braking bumps and square edge potholes...

But of course there is a light at the end of the tunnel..

Brian

www.therapycomponents.com

 

[shock]

one more

 

[Jimmy_Pop]

single pivot frame
linkage activated shock

 

[Jimmy_Pop]

www.off-road.com/dirtbike/oct99/pjc/shock&linkage_800x600.jpg

 

[profro]

I used to run Avalanches on my bikes and its well known that they are super smooth and react to the tiniest bump in the trail. However once I switched to Swingers, I noticed that the rear shock, with the platform, bounced and skipped across the small stuff. I was noticable faster. I like how the rear wheel with a Swinger stayes on top of the small bumps but yet still reacts to the bigger stuff. If I had a motor to compensate I'd run a much softer and more supple rear suspension, but as is I'd rather have a supple front end and let the rear end follow. Its a fine line though, you can't have too bouncy or skippy rear end, but I don't like too soft of one either.

 

[Jimmy_Pop]

maybe someday, we'll have air rear shocks and i can ditch the 3 pound AVY.

 

[bizutch]

Everybody's wrong...do a search for a very detailed article...in DIRT, of all places, from several years back.
They had a detailed article with Mert Lawwill regarding linkage rear end motocross bikes.

He developed moto bikes around his linkage system that worked, were within the right weight range
and did all the things like preventing brake jack and chain torque feedback.

There was one problem that the riders had with it. THEY HATED IT!
He said the motocross racers "used" brake jack to essentially skip through
sections...and that they were too used to having brake jack and had
adapted to having it.

They also hated how the bikes would stay up in the middle of the travel in
corners. They liked the torque induced squat because it kept the rear
dropped in the turn!

He said his application will work at some point when he can modify shock
technology around his linkage system, but admited he might not be the one
to do it first.

 

[zerossix]

so i may be completely pulling this out of my a$$ but isnt the determining factor of a single pivot where(if) the rear triangle attaches to the main triangle. i.e. if the rear triangle mounts directly to the main triangle (with no pivots on the stays) with one pivot, then its a single pivot, no matter where the shock is mounted. whilst something along the lines of a VPP bike that the rear triangle is attached to little mini links which are then attached to the frame.

as mentioend i could be makign this up entirely so no one yell at me, i dont pretend to be a suspension expert by any means.

 

[General Lee]

does the rear wheel attatch directly to the swingarm. . . . yes

does the swingarm attatch to the frame with only one pivot. . . . yes


then you have a single pivot

for example: giant team, orange, old intense m-1's (pre-2000), kona, rocky mountain, commencal, mountain cycle, turner. . . . and so on

 

[blt2ride]

So after reading the new Dirt Ive been thinkin lots about single pivots and linkage. I know this has been beat into the ground but I don't remember seeing too much about moto stuff. Its strange to me that none of the moto companies have tried linkage and or floaters on the swingarms? According to the guy from Mojo "brake Jack" can be combated by riding the bike correctly and that suspension performance is more about the shock setup.

I understand a moto bike might have stiffness issues with linkage and since there arent pedals thats another thing but for sheer bump absorption why do moto's only use the standard single pivot swingarm designs?

Also regarding set up? That mojo guy thinks that ultra stiff, skippy sorta setups are the fastest? Im just having some trouble comprehending. Any thoughts would be cool.

Please no flaming.

I know this is a little off topic, but worth a comment. This issue of Dirt has a 37 pound Orange 223, that is sooooo nice.

 

[SprungShoulders]

...I noticed that the rear shock, with the platform, bounced and skipped across the small stuff. I was noticable faster.

My hardtail does the same thing. Unfortunately, it reacts similarly on bigger hits. :nuts: As for being faster because of it....?

 

[bizutch]

does the rear wheel attatch directly to the swingarm. . . . yes

does the swingarm attatch to the frame with only one pivot. . . . yes


then you have a single pivot

for example: giant team, orange, old intense m-1's (pre-2000), kona, rocky mountain, commencal, mountain cycle, turner. . . . and so on

remember the ad hype Mountain Cycle posted about the Shockwave...with it's "mini-link" for the shock it was "technically" a 4-bar linkage....

 

[bizutch]

....so i may be completely pulling this out of my a$$ but ......

I'd like to ASS you a few questions....

 

[The Kadvang]

Stev Peeet Ridez A Singlre Pivot Dey Are De Bestest!!1!1!1!!

 

[Percy]

I stand corrected... looks like I'll need yer number to fact check my posts before clicking "submit reply". Just had a faint memory of being a kid and the term "Full Floater" seemed like magic. Wasn't it printed on the swingarm or something? And honda had the Pro-Link?

Haha!

Sorry,I thought the full floater was a cool sounding name as a kid too,untill I owned one.
The Prolink is the same as Honda's current design I think,they just dont call it that anymore.
The "normal" MX stlye suspension on my current MXer eats the full floater for breakfast,but that could be the 10 years of shock development between them!

 

[Rik]

Everybody's wrong...

Yeh? What you posted didn't contradict alot of the information in this thread... hmmm... too many people wanting to tell everyone else that they're wrong

 

[Jm_]

remember the ad hype Mountain Cycle posted about the Shockwave...with it's "mini-link" for the shock it was "technically" a 4-bar linkage

well, "technically" it is a 4-bar, because there are 4 components. A main frame, a swingarm, a linkage, and a dogbone. Those are the "4 bars" of the suspension.

 

[Tom DH]

So after reading the new Dirt Ive been thinkin lots about single pivots and linkage. I know this has been beat into the ground but I don't remember seeing too much about moto stuff. Its strange to me that none of the moto companies have tried linkage and or floaters on the swingarms? According to the guy from Mojo "brake Jack" can be combated by riding the bike correctly and that suspension performance is more about the shock setup.

I understand a moto bike might have stiffness issues with linkage and since there arent pedals thats another thing but for sheer bump absorption why do moto's only use the standard single pivot swingarm designs?

Also regarding set up? That mojo guy thinks that ultra stiff, skippy sorta setups are the fastest? Im just having some trouble comprehending. Any thoughts would be cool.

Please no flaming.

It down to rider’s personal choice if they like single pivot or linkage bikes. Also remember that Mojo are the UK importers for Fox and run orange bikes, but there are certain things in that article that do make sense.

Firstly this is just what I think and that is the mountain biking industry is full of hype and that sometimes things are just designed to improve sales. I am not saying that these bikes don’t work. The problem I have with them is that they work too well.

The reason that I like single pivot bikes is that they do not react to everything. At the end of the day do you really need a bike that is going to pick up every little bump of the track? I prefer the bike to concentrate on going forwards not concentrating on going up and down.

Obviously suspension is needed on a DH bike but it should be there just to maintain the flow of the bike going down the hill not to make it a comfortable ride.

Last year I had a Demo 9 and you couldn’t fault how it preformed it just sucked up everything. But it just felt really sluggish. I am now back on a single pivot and they just tending to skip over the bump not getting drawn down into them. But to some people it just feels like the suspension is crap.

Setting up your suspension on the harder side is similar to my theory on single pivots but it’s more down to the rider’s skill if they can handle the bike with that set up.
If you were a Pro rider just hammering down a track just floating over braking bumps then you could get away with a set up like that and not using a floating brake.
But for everybody else then it might not work to well for you. But if you were open minded about it and willing to learn how to ride your bike with that set-up then it would make you a faster rider.

Everybody knows this and that is that its riders skill that determines how fast you go down the hill. And everybody likes to spend money on good looking bikes.

 

[dhkid]

anyone know what the wheel path of the sunday is like?
i know that the v-10 has a very similar wheel path to the 223.
the disadvantage of the single pivot is that it has a fixed wheel path, a sector. where as the vpp sort of linkages can has s shaped wheel paths which are supposed to be better.