Cantilever VS Swing Arm VS 4 link

[7uptruckracer]

Can someone tell me the difference in design and application between the Cantilever and Swing arm or are they the same? Curious why no one uses a Cantilever? Just trying to brainstorm a way to be able to solve some of the issues with a 4 link. We all want a way to hike without excessive roll steer but also control indexing right? I mean isn't that what Rumley did? His device looks like a new school cantilever concept but now we can't separate the stuff

[Lizardracing]

Rules and packaging decide most of it however beyond that I don't think it really matters as long as you get the desired wheel loading on the track.

Cantilevers are more complicated and the mud and dust make all the moving parts require more maintenance.
Swing arms are always pushing the tire into the ground but lack the roll steer dynamics the floated four link offer.

Again, rules, packaging, ease of adjustment, over all dynamics of axle movement, front end design, driver preferences, etc all play a part into what most guys are running.

Running stuff on dirt is fun and invotive with in the means but in the overall grand scheme of technology its about 50 years old. The game changer I think is knowing how to apply what we now know and didn't then as far as math and geometries.
Live axles, carbs, 2 speed transmissions, etc....

[7uptruckracer]

Well can you explain how the cantilever is different from the swing arm? From what i saw the rumely device was like a cantilever but In idiots terms a cantilever escapes me right now. What are its goals as a design the 4 link I get completely and i understand its pros and cons. From what ive read the cantilever can give you interesting results in wheel loading as far as how it becomes progressive in its travel and how it used shock stroke compared to suspension travel, but what controls its the axles fore and aft movement?

[MasterSbilt_Racer]

Can someone tell me the difference in design and application between the Cantilever and Swing arm or are they the same? Curious why no one uses a Cantilever? Just trying to brainstorm a way to be able to solve some of the issues with a 4 link. We all want a way to hike without excessive roll steer but also control indexing right? I mean isn't that what Rumley did? His device looks like a new school cantilever concept but now we can't separate the stuff

The coilovers were parallel to the ground on the cantilever and partially a sprung mass.

[7uptruckracer]

How do you control roll steer?

[Lizardracing]

I think if you were to google it, you'll find there is about 100.000 different designs and the pictures will tell you everything.

[MasterSbilt_Racer]

I think if you were to google it, you'll find there is about 100.000 different designs and the pictures will tell you everything.

But, there are only two configurations that I know of ever being used on dirt late models

[Lizardracing]

Perhaps... but I read the OP wishing he understood the dynamics better and I was trying to make a point that a bizzilion different ways to accomplish it. Maybe i was off target.

I think if they were allowed by rules guys could come up with some wild looking stuff that worked.

[Stede Bonnet]

Well can you explain how the cantilever is different from the swing arm? From what i saw the rumely device was like a cantilever but In idiots terms a cantilever escapes me right now. What are its goals as a design the 4 link I get completely and i understand its pros and cons. From what ive read the cantilever can give you interesting results in wheel loading as far as how it becomes progressive in its travel and how it used shock stroke compared to suspension travel, but what controls its the axles fore and aft movement?

The cantilever is the predecessor to the swing arm. Canti-levers came in 2 types, forward & reverse. Most Rayburn's used what is known as forward cantilever. Imagine the lower arm on a swing arm car, but make it into a 90 degree forward facing triangle. Now instead of mounting the shock/spring on the swing arm running vertical to the ground, mount it at the top of the forward facing triangle running horizontal to ground and angle it down towards the frame rail, this is forward canti-lever. Custom Chassis, JigALo and some Rayburn's used reverse cantilever, same setup as above only the triangle is rearward facing and now mounted as the rear trailing arm, from the bottom of the birdcage. The shock/spring are still mounted at the top of the triangle only the shock/spring run to the back of the car and tend to be more horizontal instead of angling downward. Also Canti-levers aren't 50 years old, only about 30 and Randy Boggs won his World 100 with one and Clint Smith won his Hav-A-Tampa Championship with one in the early 90's. I have a friend who built a new one about 5 years ago and had good success with it before he retired. Your only limited by your imagination and the evil idiots at WRG/WoO.

Swing arm is the simplification of canti-lever. The Canti-lever designs on dirt cars were conceived by D!ck Anderson of Carrera Shocks, I have some of the early blueprints he gave me. The Rumley device may have incorporated some canti-lever aspects, but was a completely different suspension system and merely a modified 4 bar.

[old fan]

unified chassis rules for most sanctioned racing now , swing arm is on its way out

[Lizardracing]

Sucks too cause I think it's hard to beat a swing arm on the rough.

Fun Fact....Cantilever suspension used in cars started about 1910 on the horseless carriage made by the french.

[Stede Bonnet]

Sucks too cause I think it's hard to beat a swing arm on the rough.

Fun Fact....Cantilever suspension used in cars started about 1910 on the horseless carriage made by the french.
So was the "Mono-tube" shock.


unified chassis rules for most sanctioned racing now , swing arm is on its way out
I doubt that since only WoO has those rules and Lucas and many other series have opted NOT to adopt the, "Unified Rules". The unified rules also allow for swing arm, but you have to read it carefully.

[old fan]

Yes swing arm on older cars when was the last time a swing arm car ie rayburn win and that would be lucas woo ump and all its sub series mars mlra and if you are going to run the big races it will be one thoses sanctions

[LM14]

Cantilever we built in the late 90's. Worked great, just need to understand what is happening with them.

[old fan]

so was the "mono-tube" shock.i doubt that since only woo has those rules and lucas and many other series have opted not to adopt the, "unified rules". The unified rules also allow for swing arm, but you have to read it carefully.world racing groups runs ump and its sub series mars is part of it and many guys run both mars mlra cornbelt aslso

[Lizardracing]

Cantilever we built in the late 90's. Worked great, just need to understand what is happening with them.

NICE!!! I love it

I think that about just about type used. You can make it work if you understand it.

[Stede Bonnet]

Yes swing arm on older cars when was the last time a swing arm car ie rayburn win and that would be lucas woo ump and all its sub series mars mlra and if you are going to run the big races it will be one thoses sanctions

2009, on multiple occasions. Below is the last year these drivers ran swing arm and links to major series wins news articles.

Dan Schleiper was in Rayburn for most of 2007, went Wild Swing Arm 2007-2009.
Shannon Babb was probably 2007.
Billy Moyer was 2007.
Don Oneal was still in Rayburn in 2008.
Dennis Erb Jr was 2009.
Terry Casey was 2009.

http://www.stlracing.com/community/index.php?threads/dennis-erb-steve-arpin-take-wins-at-macon-speedway.113700/
http://www.thebraziltimes.com/story/1321675.html
https://www.dirtondirt.com/National_1578.html

[Stede Bonnet]

Cantilever we built in the late 90's. Worked great, just need to understand what is happening with them.

Yes, I bought a RS canti-lever from you and SPark. Still have it. Ran across a complete car recently for sale in Alabama too.

[LM14]

I do build a hell of a stout car. That car could also be cantilever on the left side, 4 bar, swing arm or Z-Link on either side. We played with a lot of stuff on that one!

SPark

[7uptruckracer]

Some of this helps but doesn't explain the dynamics very much like how it indexes and moves but I'm working on it. Just curious what the goal of this suspension was like is it a space saver is it to get a lot of hike with short amount of shock movement that kinda thing, is it a wheel loading thing like a lot of load for a small amount of travel does it make the spring progressive etc etc

[old fan]

2009, on multiple occasions. Below is the last year these drivers ran swing arm and links to major series wins news articles. I think I just heard the gossip section calling for you, maybe you should go check...Dan Schleiper was in Rayburn for most of 2007, went Wild Swing Arm 2007-2009.Shannon Babb was probably 2007. Billy Moyer was 2007.Don Oneal was still in Rayburn in 2008.Dennis Erb Jr was 2009.Terry Casey was 2009.http://www.stlracing.com/community/index.php?threads/dennis-erb-steve-arpin-take-wins-at-macon-speedway.113700/http://www.thebraziltimes.com/story/1321675.htmlhttps://www.dirtondirt.com/National_1578.html get with the times thats 8 years ago YES 8 YRS ago maybe you need to go the tail gate section

[MasterSbilt_Racer]

Some of this helps but doesn't explain the dynamics very much like how it indexes and moves but I'm working on it. Just curious what the goal of this suspension was like is it a space saver is it to get a lot of hike with short amount of shock movement that kinda thing, is it a wheel loading thing like a lot of load for a small amount of travel does it make the spring progressive etc etc

I never worked with the common versions. You could very easily, give the basic layout of the cantilever any type of characteristic you want by altering motion ratios.

[Stede Bonnet]

Some of this helps but doesn't explain the dynamics very much like how it indexes and moves but I'm working on it. Just curious what the goal of this suspension was like is it a space saver is it to get a lot of hike with short amount of shock movement that kinda thing, is it a wheel loading thing like a lot of load for a small amount of travel does it make the spring progressive etc etc

We didn't hike cars back then and canti-levers didn't index at all, they were linear... If your asking about the Rumley devices "True" intention you'll have to ask the creator, everyone else can only guess. The original "Canti-lever" was a Z-Link based design, its purpose, as explained to me by its designer was to relocate where the chassis feels the spring. Forward canti-lever has a shorter front to rear spring base than anything else ever conceived. Rumley's device was just an add-on to a 4-link LR. How it functioned can only be speculated on by anyone outside the team. Actually even referring to the action of the Rumley device as having a canti-lever like feature is only a guess by anyone other than Kevin.

[HEAVY DUTY]

Does everyone think that 10 years from now, everyone will still be saying " The 4 link is the only thing that will win". Most all of your better racers are constantly trying different stuff to get better. Most realize the problems that a 4 link has, and are trying to find a better way. Most crutch problems with shocks. Rumley figured another, must have been better way. We went thru the 4 bar thing in the 80s, then went back to leafs. Then to Cantilevers. Then on to Swingarms. Now we are back to 4 links. Something else will come along, and everyone will jump on it. It is hard to try different things, when everyone is winning on 4 bars. Then if 90% of the cars are 4 links, the odds are that they are going to win.

[Lizardracing]

The question that needs asking...Is it popular because it's better or is it popular because everyone is using it already.

Marketing is an amazingly powerful tool. More powerful than most people even realize.

That being said, if whatever design is being used id to complicated to easily use, it's not going to be popular and quickly labeled "no good" and abandoned. I think that's where the cantilever went.

[7uptruckracer]

Does everyone think that 10 years from now, everyone will still be saying " The 4 link is the only thing that will win". Most all of your better racers are constantly trying different stuff to get better. Most realize the problems that a 4 link has, and are trying to find a better way. Most crutch problems with shocks. Rumley figured another, must have been better way. We went thru the 4 bar thing in the 80s, then went back to leafs. Then to Cantilevers. Then on to Swingarms. Now we are back to 4 links. Something else will come along, and everyone will jump on it. It is hard to try different things, when everyone is winning on 4 bars. Then if 90% of the cars are 4 links, the odds are that they are going to win.

This is kinda why I'm asking the more I understand about different suspensions and seeing what works and what doesn't and why and being able to reverse engineer things the more I think it will understand current setups as well as things I can try in the future plus I enjoy the convo

[Stede Bonnet]

Does everyone think that 10 years from now, everyone will still be saying " The 4 link is the only thing that will win". Most all of your better racers are constantly trying different stuff to get better. Most realize the problems that a 4 link has, and are trying to find a better way. Most crutch problems with shocks. Rumley figured another, must have been better way. We went thru the 4 bar thing in the 80s, then went back to leafs. Then to Cantilevers. Then on to Swingarms. Now we are back to 4 links. Something else will come along, and everyone will jump on it. It is hard to try different things, when everyone is winning on 4 bars. Then if 90% of the cars are 4 links, the odds are that they are going to win.

If your on 4m much, their already claiming nothing can win but a 4 link now, for at least the last 10 years. To me its both sad and funny that so many just accept their is nothing better than 4-link and just keep drinking the Kool Aid. I shared in another thread instance where supposed truths were proven wrong. Yes they took place over several years, I don't deny this, but in each instance it was believed impossible to be done and yet it happened. It only takes some courage to buck the trend, but even then the naysayers would have an excuse or theory as to why it was the exception and 4-link is the rule.

The swing arm cars were still winning in their last year of national presence, but the tide of popularity turned and those still on swing arm were berated on 4m and at the track as being behind the times and less sophisticated. Its like that these days, its a form of bullying and I blame the Rocketeers, not so much the company but their minions. As a group they more than any other, targeted and harassed swing arm racers, especially Rayburn racers for being, "behind the times" here on 4m. Sure CJ was stubborn and marched to a different beat, but I think he deserves respect not ridicule from a keyboard.


The question that needs asking...Is it popular because it's better or is it popular because everyone is using it already.

Marketing is an amazingly powerful tool. More powerful than most people even realize.

That being said, if whatever design is being used is to complicated to easily use, it's not going to be popular and quickly labeled "no good" and abandoned. I think that's where the cantilever went.
I agree on popularity and marketing driving trends. As far as complexity, trying to be quick with todays 4link/bump stop setups to me is way more complex than canti-lever ever thought about. I'm all about keeping things simple, not because I'm intimidated, but because I see opportunities to adjust yourself out of the game very easily.


This is kinda why I'm asking the more I understand about different suspensions and seeing what works and what doesn't and why and being able to reverse engineer things the more I think it will understand current setups as well as things I can try in the future plus I enjoy the convo
I'm enjoying the conversation immensly, swing arm & cantilever are very near and dear to me as well as some good ole leafs. I think people give the suspension designs setups of today a little too much credit and discount the impact horsepower increases, tire compounds/designs and shock technology have had on overall speed. We're nearly 200Hp+ from 1995 and with more advanced power curves so the HP is more usable. JMO

[LM14]

The reason we built a cantilever well after they were available from the major manufacturers was we felt they still had something to offer with the (at the time) newest and latest shock technology and better tires. The Rayburn and Shaw cantilevers used an extremely stiff shock (6 to 8) on the rear since the shocks were controlling 750-1000# springs. State of the art shock technology back then was a Carrera Hyper Charged chrome shock! Anything else didn't work well with them. We figured with gas, adjustable, dual tube, single tube shocks that were out when we built our car let us try stuff that they couldn't when the cars were common.

Cantilever cars basically had no to very minor roll steer. You didn't need it. Roll steer became common on the extremely tight 4 bar as a crutch. The cantilever cars were, for the most part, a very well balanced car with good forward drive and side bite. Cantilever cars ran well on rough, tacky and slick tracks. They were fairly forgiving. They did not have the forward bite of a spring behind 4 bar car on a slick track we have now.

I still feel a cantilever car is viable. It will take somebody that is willing to experiment and step away from the massive support that is out there for the 4 bar cars.

JMO,
SPark

[HEAVY DUTY]

I helped on the 155 car that Randy Boggs won the World with. It was a cantilever. I had a reverse ( Custom Style) cantilever of my own. There was another car here in our town that H E Vineyard drove that was a cantilever. About everyone who drove them said they were one of the fastest cars they ever drove. The small body 5" twin tube shocks were the problem. Always going bad. They were the best you could get then though. I would like to see a cantilever with some rod angle, and rear steer. They would be pretty good I would say. CJs new swing arm stuff is way different from just a year ago. I have ran it some on a mod, and it is pretty good.

[RCJ]

This stuff would work on the spec and limited motor classes.The upper left bar transfers the weight quicker and more efficient to the tire on a 4 bar.

[Krooser]

Xxxxxxxxxxxx

[old fan]

Take this, "godless tard" for instance, he asked when the last time a swing arm car won a major series event was and when I told him he asked me to "Get with the times". 4m ain't what it use to be, too many trolls getting their jollies picking fights and hurling insults. THE LAST TIME rayburn bush was in office and its outlawed by most sanctions but carry on