: Leaf Spring Design


coyote
02-12-2002, 02:27 PM
Guys, Just got off the phone with Alcan Spring and well got an education, I always thought that springs with greater arch don't flex as good as ones that are flat no matter the design, however according to Alcan if its designed properly that isn't a problem given the proper weight ratings for the springs and such. Please let me know(constructively) what you think, yes or no...

gnob
02-12-2002, 03:04 PM
i thought alcan were spring gurus they would probably know.
the reason for instance, APs packs have 9 leaves as apposed to NWOR 3 leafers.
APs packs i belive have 5-7mm leaves (correct me if i am wrong)
and NWOR are probably 3/8 inch plus.
the thinner the leaf, the softer, thats why it requires more little leafs to amount the same lift as a thicker leaf pack.

does that make sense

RHINO
02-12-2002, 03:27 PM
yep its true, and ive said it before. i think the reason why most aftermarket type lift springs are stiffer is simply because the extra fabrication and upgrades to allow the axle to actually move is not on the mind of the average truck guy. by that i mean alot of ppl just want to lift a truck and fit bigger tires to look cool. we all know the more arch to a spring the more it lengthens if you let it move and flatten. so that requires such things as long shocks. long shackles long spline D-shafts, all the stuff only the real four wheelers are looking to do, and we all know that springs are just now starting to flex out of the box. thanks to the guys who DID all the work to show these companies that some of us actually do more off roading than dirt roads to desert keg parties.
sorry for the long winded reply.

coyote
02-12-2002, 06:39 PM
Originally posted by RHINO
yep its true, and ive said it before. i think the reason why most aftermarket type lift springs are stiffer is simply because the extra fabrication and upgrades to allow the axle to actually move is not on the mind of the average truck guy. by that i mean alot of ppl just want to lift a truck and fit bigger tires to look cool. we all know the more arch to a spring the more it lengthens if you let it move and flatten. so that requires such things as long shocks. long shackles long spline D-shafts, all the stuff only the real four wheelers are looking to do, and we all know that springs are just now starting to flex out of the box. thanks to the guys who DID all the work to show these companies that some of us actually do more off roading than dirt roads to desert keg parties.
sorry for the long winded reply.

Funny that you mention long shackles as Alcan doesn't care for them and prefers to use the spring as the longer shackle puts undo stress on the spring. They only recommend a slightly longer then stock spring, roughly 4" or so...given my expeience these guys seem to be an expert!

Explorer
02-12-2002, 07:48 PM
These are Nationals.
http://www.explorer4x4.com/rr_spring.jpg

http://www.explorer4x4.com/rr_spring2.jpg

http://www.explorer4x4.com/pumpkin_rrflex.jpg

Since these photos were taken I flipped the shock mounts 90 degrees to allow them to travel freely with the twist of the axle. The shocks are still limiting the travel. I need to punch through the floor and get longer shocks.

coyote
02-12-2002, 08:03 PM
Hey Explorer, From your picture's your getting good flex and even ripple or spring distortion which can't be good for its life, looks like a slightly longer bumpstop might help....also your arb line will hit your exhaust very soon and I would reroute your exhaust....but that's just me....other then that looks like your flexin good.......

also you flipped the springs 90 degree's sideway's or did you me 180, might try changing the angle of the shocks to a little bit further back(towards the bumper)....mine use to bind and went that route and now they don't limit me anymore.....don't see to many explorers runnin offroad....

Explorer
02-12-2002, 08:10 PM
The ARB line is an optical illusion because the photo is in 2 dimensions. It's actually no where near the exhaust.

I've been running those springs for 1-1/2 without the springs getting any permanant kinks or flattening them out. Those things flex like crazy.

I flipped the shock mounts 90 degrees not the springs. The bolt now runs forward and backward instead of side to side.

Explorer
02-12-2002, 08:13 PM
A more recent photo:
http://host.explorerforum.com/rawdeal/PB080799.jpg

http://host.explorerforum.com/rawdeal/PB080798.jpg

coyote
02-12-2002, 08:36 PM
Ok, Thought you were doing a hybrid roller but you just changed the axle mounts....looks good

RHINO
02-12-2002, 08:44 PM
nice pics explorer, thats how my rear shocks are mounted.
coyote i didnt mean like foot long shackles, sheesh, i'm sure even alcan will attest to the benefits a 4-1/2" shackle has over a 3" stock cruiser one.

ROKTOY
02-13-2002, 07:36 PM
The thing with flat springs is they sit more neutral in the travel range.
So they provide lighter up travel and less axle steer as they articulate.
Arched springs should have more natural dampening though.
Jay

coyote
02-13-2002, 07:50 PM
Rhino don't take it the wrong way, Alcan told me that a 6" shackle was extremely long and got to go to a smaller one. And I've seen some trail goer's with long shackles with multiple pin holes....and I just laugh...didn't mean to offend you when I learned 4.5 is great but add another 1.5 and it goes bad or not ideal......learning lessons everyday!