orientation progressive springs

[Brendan W]

Changed the fork oil yesterday and one of the springs was upside down. But which one? Why are progressives supposed to be close end up?

[Steve]

Why are progressives supposed to be close end up?

Because there is more mass (weight) at that end. Putting that end down increases your unsprung weight, although ever so slightly.

.

[Brendan W]

Thank you. I noticed the difference in the unsprung immediately
Deliberately overfilled and got a lot of dark grey stuff out until it ran clear. Springs are longer than stock 474mm and the spacer is a one inch aluminium plug with an o-ring on the outside and four position ramp preloaders on top - no air.
Suzuki manual says Caution about the orientation and I was wondering why. Could they end up anti-,progressive?

[Grimly]

I've always (car and bike) mounted them with closer-wound coils to the top - works well enough for me.
Progressives often work well, but not on every application and not under all circumstances. Sometimes they're a waste of money and the suspension requirements would be better served with a straight spring of the correct rate.

[Brendan W]

Could I be using the wrong term here. There doesn't seem to be progressive change in pitch- is bilinear the right name?

[Grimly]

Could I be using the wrong term here. There doesn't seem to be progressive change in pitch- is bilinear the right name?

How about Duo-Rate (sounds fancy enough to get some to part with the cash).

[mrbill5491]

Sonicsprings.com