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I just bought that second set from Eric. Hmm hope I didn't make a mistake. After reading all the input on this subject I wonder why they work for some and pretty much not at all for others. Also why would the car get loose on a road course setting with this type of spring?
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I've wanted to run these for years for the huge unsprung weight reduction, but durability testing at Chrysler (Chelsea PG) had ALL fiberglass / composite springs failing, and this was on an undriven rear axle (minivan).

If I could be convinced that something has changed / improved...

Rick



wrack71 just found cracks in his Flex A Forms he bought a year ago. Don't know the milage on them. But Mitch Lelito has had them for years. So have others.

So...





Well, while his info does come fram valid research, Rick does sometimes quote oudated data. While Chrysler may have had some failures at some time in the past, GM has used fiberglass leafs for some time as does Peterbuilt. However, like any part, you can break them if you don't take care of them or use them outside their design parameters. Are they right for you, I'd say that depends on if you are willing to do regular inspections or if you are a set it and forget it type of guy.

As to why a car would get loose with this tpe of spring..any significant change in wheel rate will change the handling characteristics of a car regardless of material used. If the rear is sliding, then you have too much rate. This is loose or oversteer. As pointed out way back early in this thread, if you change from a 140# 340 style leaf to a 175# replacement leaf, your a$$ is going to be all over the place, whether the change is to a fiberglass or steel spring.

Conversely, if you stick huge t-bars and a massive sway bar under the front with no change in the rear, you will tighten the car up so much it won't want to steer into a turn and the front will now slide. This is understeer.

This dynamc is called roll couple.