Which way do the fork springs go?


Information and questions on GL1100 Goldwings (1980-1983)
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bofler
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Which way do the fork springs go?

Post by bofler »



Re-installing my stock fork springs now, but didn't pay attention to the way they are oriented inside when I pulled them out. Tighter wound end towards the ground or towards the sky?
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redbug
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1986 Harley FLHT

Re: Which way do the fork springs go?

Post by redbug »

towards the sky and first in and then shorty. 9.8 oz.
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WingAdmin
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Re: Which way do the fork springs go?

Post by WingAdmin »

I've always put the tighter wound end at the bottom. This means it is the first to compress, before the lower rate section (looser wound coils) does. That way, the little bumps over the road compress the smallest amount of spring.

If you put it in the other way around with the tighter coils at the top, the smallest bumps have to push the entire looser coil end up and down in order to compress the tighter coils. This gives your suspension a lot more unsprung weight, and reduces the ability for it to keep the tire in contact with the road over bumps.
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redbug
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Re: Which way do the fork springs go?

Post by redbug »

Just going by the manual on page 12-16 for the 1983 narrow coils toward the top now i am confused.
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Maz
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Re: Which way do the fork springs go?

Post by Maz »

I just bought Hagon Progressives for my FJ1200 and the paperwork clearly states closer coils go at the top.
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Re: Which way do the fork springs go?

Post by WingAdmin »

Honestly, it isn't going to matter a lot - people have put it in both ways with no ill effects (or noticeable difference). But for me, for the reason I mentioned, I put them in shorter coils down.
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redbug
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Re: Which way do the fork springs go?

Post by redbug »

As soon as my message was sent a thought, its a racer/goldwing bag of trick thingies admin is talking about like oil weights drop a ounce on oil etc,got it..lets ride
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OldguyGlen
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Re: Which way do the fork springs go?

Post by OldguyGlen »

Just to muddy the waters, here are some thoughts....
I have a technical background, but am not a suspension guru, so feel free to disagree.
If you slowly compress the springs, each coil collapses per its spring rate and temper. It doesn't matter which end is up.
But if you hit the bottom sharply, as in a road bump, there is a progression, or wave effect as that shock travels up the length of the spring.
The bottom coil has to bend, at least slightly before the next coil gets the message that things are happening, and so on up the chain. The loose coils have to bend further to transmit the force to the next coil, but there are fewer coils per inch in the loose end. The tight coils have to bend a lesser amount to transmit the force, but there are more of these coils per inch. All this happens very quickly, and the math gets messy, and is dependent on inertial mass, sharpness of the impact, damping effect in the valves etc. In general I suspect the rider can't tell the difference which end is up.
Also the fork's fluid design acts to collapse quickly, then rebound more slowly to dampen any tendency to "dribble".
So why do the experts say to put the loose coil end downward? It has to do with unsprung weight. With tight coils on top, the larger mass of the tight end does not move vertically very much, as it is already in contact with the top. Meanwhile the looser end is travelling upward along with the mass of the wheel assembly. Thus it is the lighter end of the spring that travels vertically with the wheel... hence a lesser unsprung mass.
Just food for thought, for those with a penchant for contemplating interesting things, even if they aren't all that important.
bofler
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Re: Which way do the fork springs go?

Post by bofler »

Thanks for all the feedback from everyone! I ended up putting the tighter end pointing up, because it seemed like the right way based on what I had read and heard. Maybe that was wrong, based on some of the comments here. But seems to be handling ok so far.


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