Hey Folks. May I inquire as to the rate/lb. rating of the stock rear coils of a '75
914-4? Regards, -K-

I think they are in the 60 -75 lb range...but not 100% sure on that.

I can't remember either...
but have it stuck in my head that it might be 80lbs?

(pre- sag and pre- age)

brant

If you are buying new springs get the 140's# as replacements. The 80lb ones are too weanie.

I have 125s on adjustable perches and like 'em .

Guys,
the bird catalog shows stock springs as 100#
the bird never lies ( maybe)

Those are probably made by Weltmeister. I have a pair of Welt 100# springs on my car and they seemed to be a little stiffer than the stock springs when I replaced them. One thing for sure is that they raised the ride height noticeably from the original sagging spring position.

I have seen claims for the stock rear spring rate to be between 70 and 90 pounds.

914-4's were about 80# 914-6 about 90#. The spring rate is measured in the force (pounds) required to compress the spring one inch (after a preload.) Because the original springs were chosen waith a better ride in mind, they were taller and therefore had a larger range of movement than higher rated springs now have. Remember that the rear springs are a part of a system and if you drastically change one part of the system you must change others to compensate. You probabley could (and I have in the past) go to 100#ers with no other changes. I then added a stock sway bar in the front and was very pleased. I now have 140's on the car and have increased the front torsion bars to 21mm and I use a 19mm sway bar. The bar is usually set at full light and again the car has a very neutral set up.

Yeah, the original stock ones for -4's were around 75 lbs. Super soft. The "stock" replacements that the Bird sells are 100 lbs if I recall.

-Josh2

/4 springs on the left column, /6 spring info on right column