Suspension Wizz kids -- What's up in my forks??

[Baatfam]

Taking the forks apart on the 1100E for new seals and progressive springs and found something interesting....

First...the dampers had 2" spacers on them that do not appear factory...
They don't appear in the manual or in any on-line parts diagrams...

Then I noticed the springs had been cut down to 16"...should be 17.4" per the manual....

So...the question is...what did this accomplish...??
It appears that the travel has been limited and the front end lowered...
This seems to fit, as there are other clues that lead me to believe this bike was drag raced in it's younger days...

How would this affect handling...???

Thoughts??

 

[salty_monk]

They have raised the spring rate slightly by cutting off the 1.4" & replacing it with solid spacer & then also increased the preload by 0.6" (as the spacer is 2").

Pretty commion "poor man's progressive" modification on those forks although I would have cut off more like 3" of spring myself....

 

[Baatfam]

They have raised the spring rate slightly by cutting off the 1.4" & replacing it with solid spacer & then also increased the preload by 0.6" (as the spacer is 2").

Pretty commion "poor man's progressive" modification on those forks although I would have cut off more like 3" of spring myself....

Yes...but they put the spacer on the rebound side of the damper...that's what I found curious...

 

[Billy Ricks]

Most likely to limit travel like you suggested instead of strapping the fork down. The springs were cut as I'm sure you know to stiffen the spring. I'd remove the spacers on the dampers and if they are the correct diameter to fit above the spring move them there and check the sag when you reassemble. After that it's going to be a matter of riding the bike to see if the spring rate fits your needs.

Handling wise it is good for the strip, not for the street. Raising the forks in the clamps would also quicken the steering.

 

[RichDesmond]

Taking the forks apart on the 1100E for new seals and progressive springs and found something interesting....

First...the dampers had 2" spacers on them that do not appear factory...
They don't appear in the manual or in any on-line parts diagrams...

So...the question is...what did this accomplish...??
It appears that the travel has been limited and the front end lowered...
This seems to fit, as there are other clues that lead me to believe this bike was drag raced in it's younger days...

How would this affect handling...???

Thoughts??

The PO cut the springs to stiffen them, and then used the spacer to make up the difference and add preload.

Edit. Whoops, I didn't snap to the fact that the spacer was under the top out spring. So yes, this did lower the bike and limit the travel.

 

[Baatfam]

Most likely to limit travel like you suggested instead of strapping the fork down. The springs were cut as I'm sure you know to stiffen the spring. I'd remove the spacers on the dampers and if they are the correct diameter to fit above the spring move them there and check the sag when you reassemble. After that it's going to be a matter of riding the bike to see if the spring rate fits your needs.

Handling wise it is good for the strip, not for the street. Raising the forks in the clamps would also quicken the steering.

That's kind of what I thought....
The spacer is coming out...I have a set of progressive springs that are going in...
So the front end should ride a little higher...

 

[bonanzadave]

FYI

Stock 1100EZ Top

Progressive replacement Bottom

 

[Baatfam]

FYI

Stock 1100EZ Top

Progressive replacement Bottom

Yup...my progressive's measure right at 18"....

 

[Nessism]

I keep telling people that cutting the stock springs is a great way to stiffen up the front end and save the money of purchasing Progressive springs, but no one listens. Sniff, sniff. (just kidding). Cutting off the tightly wound coils are the ones to cut off since they are the soft ones.

 

[Billy Ricks]

I keep telling people that cutting the stock springs is a great way to stiffen up the front end and save the money of purchasing Progressive springs, but no one listens. Sniff, sniff. (just kidding). Cutting off the tightly wound coils are the ones to cut off since they are the soft ones.

I'll be doing it to my Gixxer forks at some point Ed. You don't happen to have that formula for the ratio of stiffness to the amount cut off?

 

[Baatfam]

So what will I notice going back to stock ride height? Slower steering?

We are only talking about 1 1/2".....

 

[posplayr]

I'll be doing it to my Gixxer forks at some point Ed. You don't happen to have that formula for the ratio of stiffness to the amount cut off?

If the spring was linear, then the stiffness goes up to the ratio original length over cut length.

K_Cut = K_Original *(Length_original/Length_Cut)

K is the spring constant typically given in Kg/mm

Taking 4" out of a 20" spring will increase 25% (e.g. 20/16 = 1.25%)

If the spring is progressive then the answer if different as the spring rate is variable and also depended on how progressive it is and where in compression you are.

 

[Billy Ricks]

So what will I notice going back to stock ride height? Slower steering?

We are only talking about 1 1/2".....

1 1/2" is huge if the fork was actually lowered that much. The mods the PO did probably didn't change the overall length of things much though. Just because the springs were shortened and spacers added doesn't necessarily mean ride height changed. If you gain 1 1/2" in length the steering won't be as quick but the bike will be more stable.

 

[Baatfam]

1 1/2" is huge if the fork was actually lowered that much. The mods the PO did probably didn't change the overall length of things much though. Just because the springs were shortened and spacers added doesn't necessarily mean ride height changed. If you gain 1 1/2" in length the steering won't be as quick but the bike will be more stable.

OK...so shorting the spring 1 1/2" wouldn't lower that much because the spring would be stiffer, correct?

Still, it was definitely lower than stock, Joe Nardy noticed that at Fennimore last fall...

 

[Billy Ricks]

OK...so shorting the spring 1 1/2" wouldn't lower that much because the spring would be stiffer, correct?

Still, it was definitely lower than stock, Joe Nardy noticed that at Fennimore last fall...

I doubt it dropped the full 1 1/2".

 

[RichDesmond]

In this case it isn't the spring being shorter that's lowering the bike. Not directly anyway. That spacer is between the underside of the damper rod lip and the topout spring. That's preventing the fork from extending as far. It's lowered by the length of the spacer. (Well, technically the length of the spacer times the cosine of the rake angle. )
The spring has to be shorter so it's not creating a ton of static preload in the new configuation.