School me on 4-links

[projektdotnet]

Ok guys been thinking about getting into "hardcore" mods and I would love the ride that can be had from a 4-link rear so here it goes. The problem I have with 4links is not understanding the way the forces act on a triangulated 4-link and how it flexes without binding so I was wondering if anyone had some good reading material so I can get out there and learn about them before really considering one.

I have been reading and understand why it works but not exactly HOW and there-in lies the problem so if anyone has good links about the mechanics of it, perferably with pics, it would be great

 

[Radd Cruisers]

Check pirates, the gods of link suspension have a hudge write up.

 

[woody]

honestly, pick up some small wooden dowels and some some screw-eyes and mock one up with some wood...for $10 in materials, you'll understand quite a bit without any reading at all.

http://www.offroadfabnet.com/forums/showthread.php?t=366 should have some good links to a couple books as well.

http://mysite.verizon.net/triaged/4linkcalcv15html/index.html
http://mysite.verizon.net/triaged/files/3LinkV1.0bBETA.zip

 

[projektdotnet]

 

[woody]

in all my discussions with Troy Meyers (owner of the Badlands in IN), he said there was one major rule with regards to suspension link design on a "stockish" vehicle

go with what fits That's your biggest limitation due to frame, fuel tanks, etc...meet the basic rules of triangulation and lengths, and mock up from there.

 

[projektdotnet]

meet the basic rules of triangulation and lengths, and mock up from there.

That is essentially where I get lost is getting lengths and Triangulation right even with the calculator I am trying to figure out WHY those numbers work I guess I'll have to look at the xls, scale the equation down and use the wood as you suggested. Thanks again Everyone

 

[ats4x4dotcom]

in all my discussions with Troy Meyers (owner of the Badlands in IN), he said there was one major rule with regards to suspension link design on a "stockish" vehicle

go with what fits That's your biggest limitation due to frame, fuel tanks, etc...meet the basic rules of triangulation and lengths, and mock up from there.

Or,

go with what you can make fit

 

[Grade8]

Making it fit is the most important thing like everyone else has said. They key thing you need to determine is the lenghts. Not too long to get hung up, but not to short either. Also a good rule is to make your uppers 75% of your lowers. I dont have any math into my 4 link at it works awesome. Maybe i am just lucky but it just works.

 

[Mace]

Also a good rule is to make your uppers 75% of your lowers.

Can you explain why..

 

[Grade8]

Dont ask me haha, thats just what i have always been told. Heck i built mine all the same length and it works great

 

[Tapage]

Can you explain why..

I'm pretty sure that you can

 

[Mace]

Actually, I can't...

It is a global "known" that works great for roundy round stuff but with any articulation it can (depending on link location) drive the pinion into the ground...

 

[projektdotnet]

honestly, pick up some small wooden dowels and some some screw-eyes and mock one up with some wood...for $10 in materials, you'll understand quite a bit without any reading at all.

http://www.offroadfabnet.com/forums/showthread.php?t=366 should have some good links to a couple books as well.

http://mysite.verizon.net/triaged/4linkcalcv15html/index.html
http://mysite.verizon.net/triaged/files/3LinkV1.0bBETA.zip

That middle link helped as I could line stuff up but the measurements I am supposed to plug in are a little confusing. I'd like to get a few more inches between a spring flip and a 4 link or possibly running my 55 rears in the front and doing the 4 link and buggy rear tube frame. The measurements that throw me off the most is CG X Y and Z I am not sure what the points for that are anyone have an idiot proof way to explain? I need to get some 1x1, 1/2" round tube and some of those eye hooks woody mentioned and start building models...maybe if I got some thin round stock I could bend up a mock tube frame...

 

[woody]

brake line works wonders for frame design

 

[projektdotnet]

brake line works wonders for frame design

good point

 

[projektdotnet]

Ok so here's my question on materials.
Would 2" OD .5" wall DOM with welded inserts be strong enough for the links?
Also would it be ok to use bushings at the frame end and 7/8" johnny joints at the axle or do you guys have something that you would recommend better. The vehicle that this will be done on will see lots of road time as it will be a long time before I can buy another vehicle to tow it with.

 

[Mace]

good setup..