I was online and found a site selling fiberglass leaf springs. Im not looking into buying them but would like to know how they do compared to metal ones, and if they're worth the extra price.
I am looking at possibly getting new springs for my ranger. I like them to have a good ride on the road but better out on a trial.

 

Composite springs have been around for,,,,,well lets say that a long time is an understatement.
Up until recently these were road use only with no intentions of running the on a trail truck.
Teraflex has a set for YJ wranglers, and I have been using them on a samuri project.
Problems in the past with the use of glass springs were running them on rocks, and tearing the surface. The end of a fiberglass spring is near if this occurs. New coatings help, but,,,,,,,

The only springs I have ever seen (that are composite) have all been monolinear springs.
This is good for weight, but not so good for axle control. Higher horsepower vehicles can expect axle hop problems, if no traction devices are used.
I do not know of too many composites that can handle the varying loads of a pick up truck.
Do you have a link that describes what you are looking at? I am curious.

 

This is the sight I found With the fiberglass springs. They even have a "Flex-Track" thing that would help with axle wrap. I havn't looked at prices on these, and if they can't handle being on a pickup like you said then Im probly not to interested unless they're really good at something- you said your using them on a sami?

Flex A Form Fiberglass Leaf Springs replace Steel Leaf Springs PRODUCTS

 

That is interesting.
I am sure there are plenty more available. The fact that they state that they will have to do some R&D for specific applications tells me that they are simply using a generic leaf, and cutting it down to compensate for different lengths. I do not know "anything" about how this will affect the rate of the spring, but like I said above, the things are pretty neat.
Gotta say they are the lightest thing I have ever installed.
For my application, I used a set of these composite springs that were available from Tera flex. Obviously thet do not manufacture them, simply re-name them, and package them as a kit. Mine were for a YJ Jeep, and I used them under a samuri. My pops is crazy about sami's (think he has 5 or 6), and one is pretty trick. I run 1.6L, 6:1 case, yota locked 8" axles with 5.29 gears, yota power steering (IFS box) high steer with crossover, blah, blah, and then these crazy springs. I had A YJ spring conversion already, and before I decided to 4 link it, these things came along. They ride nice, and get quite a bit of attention, but I am not too sure I would run right out and grab them new. I am not saying they are bad, just saying that I was not overly impressed.

 

Sounds to me that they aren't really all that special. Been thinking and remembered reading something about some explorers having fiberglass leafs. I think it was off the Ranger Station that I read it. You've got a pretty penny's worth into that samuri of yours.

 

Samis are fun I guess,,,,,I mean that thing only makes around 65 Hp. Yeah thats right
65. Maybe a little bit more, but really now. With real low gears and lockers, the little things go pretty good. I am actually suprised how well they do in the mud. Little guys are so light they move around pretty well.
Still nothing like dropping the hammer on a big block with a little help from the nitrous!
Thats a rush.

 

I'd have to agree that driving something little around can be fun- but there's nothin like being thrown into your seat by somthing big. Is that what your "'75 F350" has?

 

I have two of these ugly old trucks. One is a 75, and one is a 74. The 75 has changed quite a bit, and looks nothing like it used to, and is about as beat up as can be. Has been shortened, front axle moved foward, cab moved back, 14 bolt rear, D60 front, detroits, 5.13's, 44" rubber, blah, blah, oh yeah, and a 13:1 aluminum head 521 CI BBF. Full roller motor, with a Dominator carb and two stages of nitrous.
Nice little recipe for instant smiles. Guaranteed to put on one your face.