Progressive Fork Springs

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olympus

olympus

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Hi Guys
With progressive front fork springs.... Closed coil of the spring to the top or bottom....
I have read on here both orientations
Would appreciate your views
 
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olympus said:
Hi Guys
With progressive front fork springs.... Closer coil of the spring to the top or bottom....
I have read on here both orientations
Would appreciate your views
Click to expand...
Closed coils always go to the top,thats what the experts say.
Brett
 
I'd fit the closer coil to the top for less unsprung weight, others may know better?
 
Closer coil to the bottom = less unsprung weight (the closer coils should move first, leaving the ‘solid’ coils above it where they are sprung weight).

Opinions do vary according to different theoretical points of view, but frankly, put them whichever way you like, you won’t detect any difference in the real world.
 
I thinking some folks are applying perceived Valve spring wisdom to their suspensiono_O In front fork applications the tight /close wound coils should be fitted uppermost.
 
Because the close wound coils go coil-bound first, when they are at the bottom that mass of collapsed spring becomes unsprung weight.

Not a fan of progressive springs as I feel they compromise the damping, ie over damped soft spring and under damped harder spring, now if you have progressive damping then a progressive spring could work, maybe.
 
How do you control the spring rate of progressive springs ? - With non-progressive springs getting the spring rate right is difficult enough. To me, progressive springs seem to be a dual purpose thing and a compromise strategy. Might work well if you use your bike both on bitumen and on the dirt, and you have lots of suspension travel.
 
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I went down the progressive spring way but didn't like them and after a few big rides I decided to spend the money and invest in one of Johns Lansdown internals with stock springs, so glad I did made the whole bike a lot better and able to adjust to my riding style, the progressive springs stiffened the front end up good but was harsh on the bumps and ride, but for the price its a cheap way to stiffen the front end up.

Ashley
 
Esmerela said:
Alistair Campbell could not have put it better :p
Click to expand...

Well, I can’t vouch for Mr Campbell’s levels of expertise on such matters!

I can however vouch for mine, and will unequivocally state I am NO expert on springs, or forks, or Norton’s, or etc !

I’m just looking at this discussion from a logical perspective. And the logic of it looks to me thus:

If the close windings are there to soften the ride under normal conditions, thus allowing the firmer windings to come into play under more arduous conditions (which is what I understand their claimed purpose is), then it stands to reason that under normal riding conditions, the close windings will not be coil bound. If they were, they would be pointless. Therefore, under normal riding conditions, having the close windings to the bottom will reduce unsprung weight.

However, when those windings do become coil bound (hitting a bigger bumps, braking harder, generally riding outside of normal conditions) then the weight of the rest of the spring will transfer from sprung to unsprung.

However # 2... I would defy ANYONE to actually be able to detect any effect on the motorcycles handling whichever way the springs are fitted !

All only IMHO of course.
 
Springs I do believe are in the nebulous area between sprung and unsprung weight. I suspect the closer to the wheel spindle the mass of the spring is located the more it would behave as unsprung conversely the closer to the triple clamps the more like sprung weight. Therefor I would think one would want the greater mass (close wound coils) nearer the triple clamp. Having said that
Fast Eddie said:
I would defy ANYONE to actually be able to detect any effect on the motorcycles handling whichever way the springs are fitted !
Click to expand...
With the possible exception of top level professional rider.
 
oldbeezer said:
Springs I do believe are in the nebulous area between sprung and unsprung weight. I suspect the closer to the wheel spindle the mass of the spring is located the more it would behave as unsprung conversely the closer to the triple clamps the more like sprung weight. Therefor I would think one would want the greater mass (close wound coils) nearer the triple clamp. Having said that

With the possible exception of top level professional rider.
Click to expand...

Being closer, or not, to the wheel spindle is t really the deciding factor per se, IMHO.

The deciding factor is what moves (up and down) and what doesn’t.

What moves up and down is classed as unsprung weight.

A closer wound spring will move before a wider wound spring. In this scenario the wider wound part of the spring is just ‘weight’.

If this weight is put where it’s moving up and down, it’s unsprung weight.

Therefore, if the wider windings are mounted below the closer windings, that portion of the spring will become unsprung. I believe...
 
Interesting subject not quite akin to an oil debate (yet)
I would assume the bottom of the spring would move more than the top making it unsprung weight
So the coils that are closer and compress more will still compress more wherever they are
But if they are at the bottom they will move a lot
And if they are at the top they will move less?
Maybe spring compression and spring movement are being muddled here?
Just my opinion
 
The link I posted earlier was interesting
It said if you place the close coils at the bottom the extra coils can take up oil capacity in the fork leg!
Something I'd never considered before?
 
Closed coils at the bottom = more metal for a given space= less oil in fork slider?
 
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