Anti Dive and Anti Squat Explained - Rock Rods Tech

[@BustedKnuckleVideo]

CHECK OUT THE NEW SHOP CHANNEL FOR MORE TECH VIDEOS! kzbin.info/door/bOUUPmH1YoFXHRQuZarA5A

[@fujiuser1968]

Sitting watching this 8 years after it was made,very informative,thank you very much.

[@BustedKnuckleVideo]

Glad it was helpful!

[@yepitsme431]

I know this video is 3 years old, but its so direct and clear how you put this in practical terms its not even funny; this should be a mandatory video for ANYONE trying to understand how a link suspension works.. great video and great work man, keep it up !!

[@BustedKnuckleVideo]

Thanks, we have some new videos coming soon!

[@denelvo]

Jake knows his stuff. One comment though: around 7:00, "when you hit a rock ledge,..." When a tire hits a ledge, the contact point is no longer the point you've drawn the line to the IC from. It rides up and forward, in essence messing up you carefully plotted anti-squat geometry. Only big tires or long links can save the day in that scenario. Great stuff.

[@BustedKnuckleVideo]

+denelvo good point

[@bustedknuckleoffroadllc5060]

+denelvo good point, and i am not sure that anyone has ever calculated the change in anti squat based on the point of contact with the tire to an obstacle. From physics, rotational force does not care what point on a circumference the force is applied. You would still apply the circumferential torque to the lever arm which in this case would be the theoretical point in which the 2 bars meet in space. Id be interested to see if i am correct but i believe the calculation would remain the same and anti squat would remain the same. you got me thinking...

[@denelvo]

+jake burkey now you've got me thinking as well! :-) Yeah, rotationally, it doesn't matter, torque is torque. And the IC doesn't change, but the point of contact between tire and earth does. So the last line you'd draw, from contact patch to IC, would end up higher and come closer to the CG, for more anti-squat. At least, that's how it plays out in my head. But I feel the need to fire up SolidWorks... Weird, eh, if 'ground level' is no longer ground level? It's a pretty important datum.

[@vincewhat1]

Dude epic vids I wish more people made straight tp the point vids like these

[@BustedKnuckleVideo]

More coming soon!

[@IwillGetyou00000]

Vince Galipo, I agree man. They should be more helpful to the new guys. It almost seems like they dont want anyone to now the their secretes lol.

[@erichill5208]

I like the simple cardboard model. It made it very visual easy to see how pinyon angle is effected by length and separation of link bars

[@BustedKnuckleVideo]

glad you dig it!

[@naturelovertx]

Ok class, pay attantion. Prof. Burkey has entered the room. Thanks Jake. I love the science behind these awesome machines too.

[@BustedKnuckleVideo]

+naturelovertx needs a lab coat, class is in session

[@travkel33]

Thank you Jake. I'm building a 1/10 scale rc rock bouncer on a 4 link and keep getting squat, roll overs.

[@BustedKnuckleVideo]

glad to help

[@exileinoblivion7]

This is the single most informative 4 link video ever created

[@BustedKnuckleVideo]

Facts

[@gyrocaptin]

I think that's the best explanation I've herd ever. THANKS SO MUTCH !!! I researched the topic for months and used that calculator to guess where my links ended up. Now I have a better understanding of what to expect from my buggy. It's not done yet. Keep up the good work

[@bustedknuckleoffroadllc5060]

+Ma Roder your welcome, im glad i could help!

[@mikekins6545]

I appreciate your cardboard cut out display. I am a visual learner and I have to actually see it work to understand it. I build 1/10 scale radio control rock buggies and this information is priceless...👍🏻👍🏻👍🏻

[@BustedKnuckleVideo]

visual always helps

[@D3thM3tal]

Thank you for taking the time and explaining how these things work. You should go over proper suspension seat and harness mounting - I've seen some sketch stuff over the years....

[@BustedKnuckleVideo]

+Kyle Quitter that is on the list for sure

[@CumminsDslPwr]

+BustedKnuckleVideo So, are you trying to say I should use hose clamps instead of tie wraps to anchor my safety harness to the roll cage,...........from now on? LMAO !

[@bustedknuckleoffroadllc5060]

Kyle, just wanted to let you know we shot the videos today about harnesses and seat mounting. It should be coming out soon, just wanted to let you know sir.

[@HeliPilot303]

Paper model was excellent. Really describes everything exceptionally well. Thanks!

[@BustedKnuckleVideo]

Thought that was a nice touch

[@robertkennedy5374]

Great presentation..Once I have an idea for the mounts I like to fab temporary mounts and use black pipe with nuts tack welded on for the rod ends then you can pull the springs and cycle the suspension with jacks to figure out what you have to change before chopping up the real stuff. Just be careful axles are heavy.

[@BustedKnuckleVideo]

always fully flex out the suspension to check for clearances

[@UncleManuel]

Thanks for explaining this complex matter in a relatively easy way. That paper model is just genius! Also the short clips thrown in to illustrate what you're talking about were really helpful... :-) As someone mentioned: RC models might be a good help to visualize articulation and the effects on the driveshaft. Axial offers f.e. the Wraith rock racer and the RR10 Bomber (a replica of Randy Slawson's KOH rig).

[@BustedKnuckleVideo]

+UncleManuel good point on the RC Rig

[@wolf16731]

@@BustedKnuckleVideo I've been using this info to help with a mod on a rc, a Losi Baja Rey that I'm using for racing. Definitely good info for me to try some stuff to see if I can get it to perform better at the track. Ironically I noticed I had some driveshaft binding so this video helped me with that in addition to learning about the anti squat values I originally came to this video to learn about lol.

[@petrcejka6674]

Easy and fast way to understanding.I like your teach style,great and useful info only in every video.Can save a lot of time.Thanks.

[@BustedKnuckleVideo]

thanks much more on the way!

[@rodrigoxavierferreira7492]

Good morning, first congratulations for the videos, they are real classes. I watch all your videos and more than once. I'm Brazilian and now I'm going to start changing my JKU's suspension to do heavy trails. I have F250 axles and 40” tires. However, I really enjoy riding the Jeep on road and I have some doubts about the rear suspension. I don't know if I make it 4 triangularized links or with panhard. I was told that using panhard the car is more stable in onroad, is this true? thanks a lot

[@BustedKnuckleVideo]

Is it it long arm or short arm currently? I would stick with a panhard for the road

[@nathanielhays3183]

Great Info! Technique is a science. TRIAGE pronounced (tree-ahh-ghe) is a term medical first responders use when referring to the prioritizing of injured based on severity. The use of TRIAGED is appropriate in this application since it refers having prioritized critical points based on priority. Think french, Target (Tar-get) vs (Tar-ghey). You guys are awesome!

[@BustedKnuckleVideo]

thanks!

[@jamesmerkel9442]

jump to 13:10 for cardboard model & basic angles & arm ht set up & length as it relates to squat.

[@cartyparty7119]

this was awesome. I'd love to see a breakdown of professional suspension comparisons or something like thr genright EXS suspension. antisquat, rollcenter etc

[@BustedKnuckleVideo]

surely they know their stuff

[@tomconner5067]

Chassis inertia (u said momentum) the wheels are trying to force the chassis over and themselves and them selves under the truck with the help of the housing acting as a counter-rotating idler sprocket, (imagine the truck, on the sprocket on the wheel stacked on each other twist the wheel forward with sprocket motionless other than rotation (idling) torque and linear force because the axle housing or differential (IRS) has the equal amount of force counter-acting on it (twisting backward/axle wrap) where your springs and or links are located on the drivetrain and the frame directly determine what happens to the chassis due to limitations of the diff housing’s rearward twist/pinion up, remember an old Chrysler with a pinion snubber, everything mounted on the differential housing or solid axle that is forward of the center of the axle on the same plane will be force loaded upward and rearward equally in an arc relevant to its distance from the center of the axle, the same for what is mounted rearward (9:00-3:00 either side) 12:00 to 6:00 (left rear viewed from the right of the machine) changing the elevation changes the upward to rearward force ratio (fore) and the to downward to forward ratio (aft) Figuratively speaking, if the coils are mounted forward and significantly below axle center the engine torque will apply axle counter force forward and upward do attach the other end of the component where you want that force applied. Just ask yourself why and to what degree to suit your goals. I woukd illustrate but its lat-early! Man i gotta hit the rack

[@BustedKnuckleVideo]

wow that is a lot of info

[@tomconner5067]

Sorry I was on a roll!

[@stevenpope9304]

Thanks for the video. You do an outstanding job explaining the concepts. And you are spot on about the forum.

[@BustedKnuckleVideo]

Thanks for watching, we have more on the way

[@Tapage]

Guys .. this it's awesome stuff .. glad to be the first one in say thanks and keep those tips coming .. another less interesting topic might be tires, and combination of boggers with SX front and rear or even when you groove them. Even tho I believe there is much more we can discuss about suspension, related to shock and suspension frequency for different applications.

[@BustedKnuckleVideo]

+Tapage We have a ton on tap. Stay Tuned!

[@patrickschliesing1294]

A scenario you explained at 9:01 spoke to me. I built a long arm 4 link + panhard front for an XJ recently which is having a hop issue when climbing uphill. When designing the long arm suspension, space was the ultimate constraint, but we tried to triangulate the lowers by 15* and triangulate the uppers maybe 5-7* around the oil pan, but it still needed a panhard bar. The uppers are nearly flat (parallel with the ground) and the lowers are sloped down a bit from the frame to the axle mount. When I plug in the final actual measurements, the anti-squat summary calculates to 102% (using 4BarLinkV3.1d). Is this 102% value the "reason" why the front axle hops when climbing up a hill? The scenario is you get to the crest of a hill but you need to keep spinning the tires, hunting for traction, to get over that final crest. Instead, the front tires just spin and hop, lifting the tires about 1/2" off the ground per hop, and it's nearly every rotation of the tire...so imagine some pretty violent and annoying hopping. If I reduce the front's anti-squat number to somewhere in the 80% range, will this help or hurt the issue?

[@BustedKnuckleVideo]

Good question. I will consult jake on this one

[@mirhanadewi5242]

Nice skill jake. Thank you video matt

[@BustedKnuckleVideo]

Thanks for watching!

[@HiddenInstinct]

Great videos. Helped me a lot with my front 3 link and hoping to do my 4 link this winter.

[@BustedKnuckleVideo]

4 link for the win

[@husq2100]

Anti dive is calculated slightly different, including brake area. It’s a braking force, not acceleration force hence the difference. Under acceleration you have anti lift in the front not anti squat. The tyres are rotating the same way, the axle housing opposing the same way, but the links are on the other side of the front housing.

[@calpdal1]

Great video!!!!

[@BustedKnuckleVideo]

Thanks!!

[@Dew411]

Thanks so much for all the info ! I am starting a new 07 jku project with dana 60,4 link just getting started !

[@BustedKnuckleVideo]

heck yeah super 60?

[@Dew411]

Can friend me on face book ? Then I can send pic detailed info !

[@BustedKnuckleVideo]

I have an 08 JKU I plan on doing the same with

[@RCscooterMods]

i am watching these videos to learn on my rc rock racers and monster trucks haha. awesome videos, love it.

[@BustedKnuckleVideo]

That is awesome!

[@eliinthewolverinestate6729]

You can tune for anti squat with air bags or electronic shocks. I don't like wheel hope. I added coil over shocks for anti dive. I run parallel 3 link upper wishbone that are eye to eye same length as driveshaft. And rear pinion pointed straight at output at ride height. Dropped transfer case 2" with a sye. Need to change front end uppers and steering geometry. One trip wheeling destroys the track bar.

[@BustedKnuckleVideo]

it takes a lot of work to dial in a suspension right

[@brandonc4897]

Great videos! Could you touch on bottom triangulated 4 links? When the top bars are straight and bottom bars are triangulated?

[@BustedKnuckleVideo]

+Brandon Cobb We only do double traingulated on rock bouncers

[@hillrodfilms5262]

get a rc to use to show in scale . love it learned a lot thanks

[@BustedKnuckleVideo]

+Arkansas andy not a bad idea

[@electricdeckhead3083]

@@BustedKnuckleVideo these vids have helped me a lot with my custom scale rc builds.

[@Mcneds]

CYCLOPATH same but I build mine out of lego

[@Sawdust65]

Ur cardboard model of the suspension is awesome!

[@BustedKnuckleVideo]

It helps it make sense

[@KaosProject21]

what if we drop the upper closer to the axlebin the *back* to increase our squat? obviously reducing link separation isnt great for axle wrap, but if your sticking a mild lift kit on a basic solid axle, the shock perch on the axle usually gives you at least one lower hole, usually two, that will change your instant center...

[@miked90123]

Great info! Thanks for taking the time to dumb it down lol! Even though I'm 3 link front and 4 rear already, the suggestion of a multi mount link mount for shake down is great! I'd like to see the pro/con of suck downs when time is limited and changes need to be made when mother nature throws in her two cents. Thanks again

[@BustedKnuckleVideo]

+miked90123 suck down winch is a good idea on steep climbs

[@Jonesz24]

Sweet video . I have built a crawler with a gradder ball in the rear and four linked the front , taking everything you said into consideration my question now is will different shocks play a factor into this ? I mean like a 2.0 air shock vs coil over w bypass ...

[@BustedKnuckleVideo]

+bjonesmoto2424 it will not change the way the suspension moves. Just how fast or slow it moves.

[@jsburkey]

The 4 link geometry will remain consistant with different shock combinations. Shocks will simply dampen the spring oscillations and therefore the frequency of suspension movement.

[@rompdude]

+Jake Burkey See I mentioned this a few years back on pirate and got shot down. In theory, if you have a large damping amount, the bounce frequency will be reduce (and possibly gone?)

[@jsburkey]

You are correct, a large shock valving would reduce the oscillation of the anti squat bucking (think solid block between the chassis and rear end) but this is NOT the proper way to do it. You would end up suffering in all other aspects of suspension performance to reduce it.

[@Jonesz24]

+Jake Burkey ok , for give my lack of knowledge .. I'm currently running 18" fox 2.0 and when In 2 wheel and apply the brake some times the front will completely raise up , throw it in gear or N it lowers back to ride height .. Granted the 2.0 are maxed out (psi) , so I was wondering if I run coil overs on front if this will help .

[@TheHighDesertLife]

should make a video about roll cage strength design and proper gusseting seat highth and proper head clearance I see a lot of people on the web in forums build there cage without factoring head clearance , loved the videos very educational ,

[@BustedKnuckleVideo]

Here you go- kzbin.info/www/bejne/jJnFfpdpZqmpp8k

[@roadhouse71]

Thanks for being a straight shooter. Hope to met you at Boo Bash next weekend.

[@BustedKnuckleVideo]

Riot is done for the season and For Sale while we build the new Riot 2.o

[@rifleman7313]

Great analysis and explanation, I was just thinking about building a lifted 4x4 crown victoria (6" lift on 30"-31's with an Atas II transfercase). I know hardly an off-road build looking more of a streetable ultra4 police interceptor build. I think that the wheelbase (roughly 114" wheelbase) and tire size (30"-31") is probably going to be way off. What do you think?

[@BustedKnuckleVideo]

sounds like an interesting build

[@marckilpatrick]

Calculator made simple , awesome video!

[@BustedKnuckleVideo]

+Marc Kilpatrick thanks

[@guillermopayne9950]

Wow! That sure made it a little easier to understand. Going to follow you some more and see how much I can learn. Thank you!😳🤔

[@BustedKnuckleVideo]

More Tech vids coming soon from Jake!

[@sebwiers1]

Great video, hope you do / have done more of this sort of thing. I started looking for info like this about 5 years ago when I wanted to build a 4 link front end for a motorcycle, I ended up buying a program that does many of the same things as the "triaged" spreadsheet but specifically for pivot based motorcycle front ends. Amazing to see how much crossover there is (but not exactly shocking - the physics and even some of the parts used don't change). The whole reason I started my project was that motorcycle forks all inherently have very low anti-squat value (in fact its a negative calculated value) and I wanted to try some higher values, and even more to be able to adjust the value and see what it feels like. As you say, you don't know what works until you try it, and (for motorcycles) it seems like very few people have ever actually "tried it" with different values of front anti-squat, simply because conventional forks have no such option. I dug up a copy of the 'triaged' spreadsheet (after finding many dead links - looks like its about 10 years old). I've wanted to try doing something similar to that (and to the program I purchased) but as a web app, could be the spreadsheet will give me a chance to dig out some math. Doing my own would allow me to address some cases the software I bought does not allow, wondering if mybe there's some oddball cases in 4 wheeling that might be worth considering. (Also not sure what all triaged does, having not played with it yet; I'm aiming for charts of dive, trail, & rake vs suspension position).

[@BustedKnuckleVideo]

way to think outside the box for a motorcycle, it's not surprising that many of the principals apply the same

[@sebwiers1]

Its not my thinking, I just built one. BMW sells one (on the K series bikes) and the patents (from both Norman Hossack and Claude Fior) are so old the have expired. An old school girder fork has the same 4 links as well, but tends to have large camber & trail length changes if set up for anti-dive.

[@Boogerweldz]

These vids are quite good and grab the main concepts in a way easy to understand both in your visual aides, and your descriptions of actual scenarios on an trail obstacle or a Mcourse. It got a little ambiguous in how AS/AD work at high or low figures, almost describing them the same, but the your trail scenario examples draw a better mental pic. If I could add, the caster changes throughout suspension travel are low on priority in most cases. This is articulation, not jumping or desert. Much of what you described is more prevalent in a front or off set axle at the ujoint, But is almost nonissue for centered, especially a rear when caster means nothing, only a ujoint bind would be of concern. The entire axle needs to do these huge changes, not much of this happens in articulation and should be less of a concern if you are forced to mount a link shorter/longer/etc because of available space on the chassis. A simple limit strap at the axle center or above the diff wi t hamper flexing, but will keep the driveshaft happy. You can use it for loose attachment of ARB lines, brake lines, etc safely protected from over extension as well. You can’t feel AS or AD numbers changing from 40-55%, it’s likely the vehicle won’t even yield a performance difference. It’s 40-130 that’s apparent and has elements of concern. 40 being great in the rear, but not so much as a fronts where brake dive would be an issue. Yet 130 would be wasted propulsion forces in a rear suspension as lifting, in front it would work as a traction aid and a force in opposing brake dive. More important that anything for the most part is not how instant center relates to CofG, but roll centers can totally foul up a vehicles handling and if not a dedicated crawler, a potential disaster. If you don’t respect and understand roll centers and buikd them flat or at least out of oversteeer, then stay the F@ck off public highways! Way more important than an As/AD or caster changes through whole axle compression/droop. A short arm TJ lift of 4+” is a great example of how everything can be ruined in a lift kit that only lifts. An 80 series landcruiser at higher lifts(so I’m not being a racist, lol) quickly has similar issues and both are hugely evident if you use the online spreadsheets by Dan Barcroft (triaged) described in these videos. Lastly, when hitting a rock or log on the trail, it’s affect on suspension would be vaguely the change in instant center to new contact patch(a raising of instant center and AS/AD affectively, but there’s an element of tangent not accounted for in that, the closer to parallel and inline with instant center the less impact that creates on vehicles motion. But a 3 foot boulder at 20 mph is what it is, lol. Long (32-38”) flat links are always and have always been good advice. 25% of tire diameter isn’t relevant if you build the link mounting points at a ‘strength’ level consistent with the increased torque they would absorb with less seperation. Or vice versa. But it’s a safe figure for generic brackets of a36 .250 from anywhere and your average welder. That could easily be 6” on a 40” tire safely with more elaborate brackets supported in multiple planes (not two lower link tabs welded downhand on a 14 bolt axle tube for example)and wrapping around axle tubes further. Again, nice to see someone making videos that truly represent concepts so anyone can relate instead of bad info on a google search from ill informed web Nazi’s!!! Hats off to you sir. I gotta subscribe and watch them all!

[@BustedKnuckleVideo]

Wow you wrote a lot, I'll send Jake over to answer.

[@Boogerweldz]

Yeah, sorry, I was on the toilet and lots of time because last nights dinner was huge!🤪 Finally someone who grasps things in both front verses rear driving axle and the push/pull on the links working opposite. not some boner shooting for the same figures on both from total ignorance. Cool description on the conflicting way some designs work(or kinda don’t) in east coast hill bouncers in loose dirt vs west coast style of say ‘back door, or wrecking ball just over wheelbase length waterfall launches.

[@markwyatt3088]

So a 2door TJ Wrangler with a 2" lift because it has a 93" wheelbase can't run 35" tires? I agree; I switched to 31s and the street squirreliness was noticeable, anti squat & dive effects decreased. I 'wuz wondering if totally stock Jeeps have suspensions tuned for the stock tire/4 link/ spring rate & shocks or if they can be improved with mods.

[@BustedKnuckleVideo]

they can all be improved with mods, especially when you correct the geometry

[@chandraprakashrnaidu4867]

Hi there biggggg fan of yours!!! If possible can u make a video on suspension calculations on grid sheets and softwares later all together or suggest a link for that???

[@BustedKnuckleVideo]

we have more suspension videos coming soon, there is a 4 link calculator on google that is helpful though

[@eldiablobiker]

Looking for advice. 05 Tj 3.5” rubicon express long arm, 1” body 38” tires. Currently has the radius arm in the front and I am switching it to 3 link. I plan on using the calculator to figure out where to place everything. What my question is, is what numbers am I looking for to make my front end not so light? It loves to lift the front. I am stock wheelbase and a stretch is not in the budget.

[@BustedKnuckleVideo]

there are a lot of good threads on the internet about how to design your 3 link to work best.

[@jacobrocha5734]

Thank you for making these videos. I have learned a ton.

[@BustedKnuckleVideo]

Glad to hear it! We are working on some new ones now

[@rebvarmameh9313]

Hi.i have a question. Why toyota in 80 and 100 series use 5 link suspension? Why they dont use 4link with triangulated design instead of 5link and panhard in rear suspension??? Which one is better? And Thanks alot for your good video.

[@BustedKnuckleVideo]

they do a 5 link for better road manners and safety

[@PhilipHousel]

Great job presenting these technical details. I'm curious, is there binding in the triangulated 4 link when articulated one wheel high the other low?

[@BustedKnuckleVideo]

If done correctly there should not be.

[@Motoxfmx27]

Busted Knuckle/Jake, I've watched your 4 link explanation and your anti dive/anti squat videos numerous times. The videos are definitely helping me understand a link suspension in greater detail than before. I have a leaf sprung solid axle swapped GMT800 Sierra. I'm planning on linking the truck within a couple years. My question...when I go to measure the height of the CoG, do I use the stock height or the height of whatever it measures to since my truck is lifted? Thank you.

[@BustedKnuckleVideo]

it will be different since you lifted your truck

[@Motoxfmx27]

@@BustedKnuckleVideo Thank you for your response. I'm doing a lot of reading on Pirate and other forums. I'd guess my truck is lifted around 9 inches. Once I feel comfortable enough to link the front end, I plan on lowering to around 6 inches of lift. I figure I'll set the truck at the new lower ride height I want and then use the CoG height (either centerline of cam or top bell housing bolt) when I'm ready to use the 3/4 link calculator. How does that sound? Thank you for your videos and your willingness to help and answer questions.

[@ilikspltv8377]

Thanks brother that was the best video an example of this! Even for 2020!

[@BustedKnuckleVideo]

glad it helped

[@kc5zmv32]

good stuff on late model dirt car i had 3bar on rear whats the diff i won races thinkn bankn and forward bite

[@donniefeathermanjr2835]

Great videos, I have a 1979 Scout II project that I plan on building to be my daily driver and weekend trail rig. Im down to a rolling chassis at the moment. I find your videos very helpful but Im lost when it comes to choosing shocks. How do I choose the correct location,and position of the shock? Then choose the correct shock for the application? Also does the shocks range of travel effect anti-squat/dive and design based on desired ride height? Is there a video that you have or plan on making to add to your suspension design series that may answer these? Thank you

[@BustedKnuckleVideo]

Good questions we will dive into these very soon

[@donniefeathermanjr2835]

BustedKnuckleVideo sounds good looking forward to it

[@TheAmericanUhate]

So for a crawler, I'm thinking high anti-dive/low anti-squat, will pull both ends down. Also what about roll center on side hills?

[@BustedKnuckleVideo]

roll center needs to be low as possible

[@justevan938]

Thanks Jake. This tutorial was awesome!

[@BustedKnuckleVideo]

More Suspension tech to come

[@justevan938]

I'm working on a "75 CJ5 crawler with a ford 9" rear and dana 44 front axle and am currently swapping over from the stock 1.75'' leafs to 2'' with boomerang drop shackles. My front is already 4 linked, but I like the leafs in the rear and am using this video and the world wide webs to build my ladder bar in the rear. THANKS AGAIN!!!

[@BustedKnuckleVideo]

awesome, sounds like a fun rig

[@justevan938]

Videos to come...

[@micahhaislett3792]

I’ve watched this five or six times over the past year. I’m finally about to start setting up my four link rear and three link front in my tj, mostly rock crawling with some steep hill climbs (typical Jeep crawling trails type stuff) I’m pretty sure based on what I’ve read and what you said that for my application I should shoot for about 100-120% anti-dive or as close to it as I can get with all the shit in the way. And it looks like with how I have it set up right now my anti squat is going to be about 150-160. I might be able to get it a little lower, but again space is limited, and separation at the frame at this point would mean lowering my lower mounts, losing clearance. Am I on the right track here? I’m building this by myself with no prior knowledge and no one around me that knows anything about it, so the internet has been my only mentor. Thanks for taking time to do this stuff bub. 👍🏻

[@BustedKnuckleVideo]

100 is a good number

[@tree18is]

the least I could do was drop this comment for an awesome video! that cardboard HP was awesome

[@BustedKnuckleVideo]

lol, thanks for watching!

[@OffroadMilitia]

If 100 is neutral is that also considered high for a rock crawler should I shoot for 110 or should I shoot for around 90%

[@BustedKnuckleVideo]

Over 100 will make it rise when throttle is applied, less would make it squat. 80-90 is good.

[@husq2100]

With your scale model, WITHOUT changing the Antisquat, if you shorten the upper links it DECREASES the rising RATE of Antisquat through droop.

[@danielmay7107]

This video helped me so much! thank you! I also found something interesting. When the upper and lower four links are of different length, the anti squat value can change a lot as you start squatting.

[@BustedKnuckleVideo]

lots of variables when calculating these numbers

[@jeffyoung2089]

great videos and information!!!!

[@BustedKnuckleVideo]

+jeff young thanks more to come

[@kookertech]

Really enjoy your tech videos. Can any of this be applied to independent suspension?

[@JbassPlayer28]

Yep. Apply same concept of instant centers to side view with the frame mounting points. Draw an axis for upper a arm and another for lower

[@BustedKnuckleVideo]

it can be

[@LawrenceTimme]

Another absolute amazing video. 👌🇺🇸🇺🇸🇺🇸

[@BustedKnuckleVideo]

more of these coming in 2020!

[@LawrenceTimme]

@@BustedKnuckleVideo great to hear. I hope you had a great Christmas 👍

[@longrifle.]

Very informative, thanks Jake.

[@BustedKnuckleVideo]

he knows his stuff

[@devenbelanger8463]

I wonder if I’ll get a response from him. Here we go, I’m making an off road buggy. I have a retired sprint car frame a sb350 th400 trans and a 203 tcase. Where my axle will be mounted is right at the rear of the frame which leaves me with a rear driveshaft that is 18”-20” long. What would be the best set up to keep my shaft from grenading. Front axle and suspension is a little easier as I have more room and shaft length to play with and adjust. Thanks in advance for any input

[@BustedKnuckleVideo]

there are a lot more variables needed to make that decision

[@devenbelanger8463]

BustedKnuckleVideo it’s basically gunna be a universal rig. Not a whole lot of rocks but mud and trail riding. Braking trails like a go cart on steroids. I have 40” loader tires that will be goin on it. Not sure what else you need I just don’t want to have to keep tearing it apart and rebuilding it. I love all yer videos and watch them religiously. You explain things so well and the visual aids are awesome. I appreciate the response man. Thank you

[@devenbelanger8463]

BustedKnuckleVideo I wish I could show you a picture of it but I don’t think I can on here

[@markm7779]

Excellent ! Simple and informative I like it.

[@BustedKnuckleVideo]

+Mark M thanks more to come!

[@MrGuitarguyadam]

I’m building a 600hp bbc powered leaf sprung trail rig... how do I tune for anti squat and anti dive on that?? Traction/ladder bars put in the correct places?? But then I sacrifice ground clearance with some vulnerable bars down there

[@BustedKnuckleVideo]

You don't. You swap the leaf springs for a properly setup 4 link.

[@michaelbaca7093]

Leaf springs are a "Load bearing device." You squish them from the top, then apply enough force to turn the tires, but without peeling out. Leaf springs are a "Static" or "Stable" device for steady drivers. Cal-trac bars are meant to stop the leaf springs from getting wound up and hopping on a street vehicle. Technically, that makes leaf springs a no-anti squat 4-link, but that might be an insult to 4-links. These Busted Knuckle guys are more experienced than the Engineering Explained guy, and are giving you very valuable advice. A 4 link with multiple holes is a formidable implement.

[@tonyfields5195]

Awesome video. Thanks!

[@BustedKnuckleVideo]

Glad you liked it!

[@nickbagby36]

Do the upper link bars on a rear 4 link have to be at 40 degrees? My lowers are at 45 degrees but to keep the bars the same length I would need the uppers to have a little less triangulation. Is that ok?

[@jacknicholson5794]

Great video. 1 question though, when inputting the tire diameter is it a good idea to take into account that it might be smaller than the printed diameter as well as how much it will squish down with weight on it at a given psi? Supposing I know the distance from the ground to my axle centerline with all variables considered, could I multiply that by 2 and call it my tire size to get the most accurate instant center? Thanks

[@BustedKnuckleVideo]

+Jack Nicholson It is just a guestimation. Your tire size will change as you air up or down and hit obstacles.

[@bustedknuckleoffroadllc5060]

+Jack Nicholson take the measured tire diameter for the tire size input.

[@tonybriley2100]

Great video Jake

[@BustedKnuckleVideo]

+Tony Briley he has this instructional stuff down

[@tonybriley2100]

+BustedKnuckleVideo I have been on Pirate for years and I learned more from Jake in that video than I ever did on the forum. The visual aids helped big time.

[@BustedKnuckleVideo]

+Tony Briley we try, so much more on the way

[@jacobaaron978]

let me start off by saying I'm a jeep guy, weekend warrior at best. one thing I've heard thrown around on the forums is really simple and wanted to know what your thoughts were. they simply say 4" separation at frame and 8" at axle with equal length uppers and lowers. opinions?

[@bustedknuckleoffroadllc5060]

you cannot have set numbers that work for any vehicle. There are too many variables for those numbers to stay true under all circumstances. you will need to plug your numbers in the calculator to be sure your building the suspension properly

[@scraptech3152]

dude i appreciate all your videos. your videos are well done and all the info is priceless. im working on my own build following your videos however i cant find what mods you did on your axles before you went to the custom 14 bolt in the front. were you running a spool

[@BustedKnuckleVideo]

spool for sure

[@jesseortega8598]

Awesome Tech Video on anti squat! I was wondering if you were going to do a Video on Engine Horsepower and wheel speed. It seems that some guy's don't have the power or wheel speed or momentum to get up the Hills like you and the other high horsepower Buggies. It sucks because I see em struggling.

[@BustedKnuckleVideo]

There are so many variables to get wheel speed, horsepower, trans, t-case and axle ratio all play a factor

[@ipodtouch4321]

Thanks for sharing. I love watching your videos!

[@BustedKnuckleVideo]

+Jake Montgomery Thanks for watching!

[@ChrisSuperTube]

Can you get into suspension setup with regards to torque twist please?

[@BustedKnuckleVideo]

+ChrisSuperTube ill see what we can do

[@timothysirmon1655]

If you’re using a 4 link as a lift does the center of gravity need to be taking now or when the vehicle is at new ride height

[@BustedKnuckleVideo]

ride height

[@timothysirmon1655]

@@BustedKnuckleVideo and how do you know where the center of gravity is when you are doing a solid axle and other modifications during the four link build to make sure everything is set where you want it

[@rowdyridesbryanacres3106]

Please help. Im building a big diesel bog truck. Every truck like what I’m building I’ve seen, when accelerating they squat tremendously. I’m running 67” tall tires and the truck is a crewcab short bed 2500 ram. My goal is when I am accelerating or hooked to another truck on the tug pad my truck doesn’t squat like everybody else’s but I also don’t want the suspension to look ridiculous. Thanks for any help.

[@BustedKnuckleVideo]

Anti squat is your friend in that case

[@rowdyridesbryanacres3106]

@@BustedKnuckleVideo yes but with my instant center so high my link bars would be at extremely steep angles up to achieve this. The truck will be around 11’ tall. It didn’t seem possible unless the bars look ridiculous.

[@highoctain113]

Building a 4 link that can take a beating, how can i determine most efective mounting angles or positions for the shocks and springs

[@BustedKnuckleVideo]

thatll be a whole nother video. Straight vertical is how they are built to be mounted.

[@elcapitain9709]

awesome videos, keep up the good work.

[@BustedKnuckleVideo]

+elcapitain9709 thanks

[@rafhonda2011]

hello, i have a question about adjusting my suspension arms I do a lot of winter trail running and what I noticed is that I do a lot of wheel ops on the front tires and I would like to know how to reduce the wheelop without taking too much of my low traction in the rocks? I have a 4.5 suspension with adjustable arm but on the oem brackets on my jeep jlu diesel is sque I should watch more vote antisqwat or antidive pcq I have at least 125% antisqwat but more around 70/80% antidive thank you

[@BustedKnuckleVideo]

Long arm is your best option to prevent that. A good set of shocks might help bandaid it some. My Jeep JKU with short arm 4.5 kit never wheel hopped.

[@robertmorris7998]

Trying to figure out how the 4 link calculator works .... did the rear just fine but the front is off the page forward the front axle . Tried all i could come up with .... any tips ?

[@BustedKnuckleVideo]

good question, not sure what would make it do that

[@robertmorris7998]

I had to run - numbers for my link lingth it shows up correct on the layout

[@danyst-gelais9505]

Great video but I just can't get over the fact that the truck at 11:34 didnt even broke when he landed 🤯

[@machinistzhang3632]

So more length separation at chassis, more likely it'll do a wheelie when taking off. Is that correct ?

[@BustedKnuckleVideo]

on the front?

[@machinistzhang3632]

@@BustedKnuckleVideo the rear I mean.

[@desmvp]

On the calculator what is a "high antisquat #" , mid # and low #" just looking for an example. Great vid.

[@JKGearandGadgets]

Hacker 4 Life OSS think of 100% as neutral.115 would be high, 80 is lower.

[@desmvp]

@@JKGearandGadgets thanks that helps

[@reubenhunt7750]

After installing a spool in the rear axle now I'm getting crazy bad body roll. Can you explain why

[@BustedKnuckleVideo]

roll center might be too high

[@FRCyoung]

when u built your buggy and did the suspension setup what ratios did you use and why

[@BustedKnuckleVideo]

+FRCyoung +Jake Burkey will have to answer that one

[@bustedknuckleoffroadllc5060]

+FRCyoung my buggy was built by Jimmy Smith motorsports originally. I think he licked his finger and went with where the light shined off. For the 2016 season i have made drastic changes to my suspension to help performance. Unfortunately, im not going to tell all my secrets... Gotta stay on top!

[@onemeangreen]

First thank you, I know this is an old video, so is my project, started 4 years ago. Accidents happen. Question, watching your cardboard 4 link the lower pivots at the center of the axle, what change is seen if you move it to a real location say 3-4" in front of the axle and below the tube center line 1"? I am reading other articles stating make the upper arm longer than the lower to keep pinion angle directed at output as you said, yet stated in the same paragraph the rule of thumb is make the uppers length 75% of the lower. Is the link length based on the frame mounting point as longer or the actual link length since the upper link mounts farther back and on top the truss and the lower mounts in front of the axle. My upper links are 2.5" longer than my lowers but my lowers mount 3-4" further forward than my uppers. This is a daily driver/toy that started as a dual use toy. Again thanks for the time

[@u-genefabricationmachine4725]

can I run a triangulated four link on the street or is this just for off road only?

[@BustedKnuckleVideo]

PLenty of people run them on the street

[@MrMrsregor]

0:22 so true. funny how even the pros know about the pirate pricks

[@BustedKnuckleVideo]

yeah Pirate isn't good for asking questions

[@snek9353]

I haven't found the forum useful in years, ask a simple question get flammed, ask a hard question nobody knows, call them assholes or flame back get banned. F'n useless.

[@tjmiller8309]

I'm still having a hard time understanding this in a long arm jeep application. On the front most companies have a choice of a single sided radius arm or a 3 link type set up. I get that the absolute center changes in these setups but what exactly does that do? The goal is to use anti squat to reduce unloading on a climb. But in a normal street driven weekend warrior type build is this overthinking it? I'm not racing ultra 4 or looking to do the baja 1000. Is the 3 link the new trend so everyone wants it even if they dont need it? Is the reduced potential to bind the u joint with a radius arm more of a benefit over the anti-squat?

[@BustedKnuckleVideo]

radius arms bind by design

[@tjmiller8309]

@@BustedKnuckleVideo true if it's a dual radius arm but there are kits out there that have a radius arm on one side and a lower control arm on the other. Thus eliminating the bind in the same way as a 3 link.

[@50kngocdn]

Thanks I figured It out 😁💪

[@BustedKnuckleVideo]

Nice job!

[@nathan00campbell]

so for street use i would want 0 antisquat/dive to keep my caster angles exact at all times, truck is not a hot rod and will see lots of street use. mostly low speed off road trail riding, mud, and dirt, not much climbing as its all flat country here. does this sound right,,, this will be my first time building a 4 link the rear im going to go for just enough antisquat to keep the ass from diving under full throttle acceleration on pavement tires are right at 40" and the arms will all be as long as possible while keep the triangulated angles no less than 40* as you stated in your last video i want an off road capable truck that dont beat me to death to drive it, currently its leaf spring all the way around and rides like a lumber wagon and is so stiff it dont even need swaybars even at 10" of lift

[@BustedKnuckleVideo]

sounds like you have a good handle on it.

[@bustedknuckleoffroadllc5060]

0 anti dive will cause the vehicle to dive when the brakes are hit. You want a higher number in the front to keep the nose up when your on the brakes. Other than that, your right on

[@JohnDoe-ft8zs]

Your the best bro, dont hate, educate. Sometimes you sound like your speaking Spanish to us laymen's.

[@BustedKnuckleVideo]

there it a lot to know about suspension

[@JohnDoe-ft8zs]

@@BustedKnuckleVideo well thanks for the insights brother

[@BustedKnuckleVideo]

John Doe glad we could help

[@SpokesandRotors]

Love these videos keep them coming.

[@BustedKnuckleVideo]

+Three Percent Patriot thanks more on the way

[@aoi-saezuru-tori]

Great job bud!

[@BustedKnuckleVideo]

glad to help

[@piotr.maruwka]

greetings from Poland ! Thank U

[@BustedKnuckleVideo]

+Piotr Maruwka greetings! they have offroad in poland?

[@johncranfordpersonal4146]

Very, very helpful.

[@BustedKnuckleVideo]

Glad you think so!

[@ChrisArters]

Great video!

[@BustedKnuckleVideo]

+Chris Arters thanks!