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Discussion Starter #1
So I had a Kawasaki ZR7. One of the things that alot of people did to stiffen the front was to add a pvc spacer that was longer than the stock one. I have looked through the forum and I could not find if anyone has done this to the strom as the lone temp fix for the problem.

The other question is this. I look at the top of the forks and I can not tell if the preload is all the way down. The center piece with the slot in it sticks up about 3/8 of an inch.

Thanks
Al
 

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So I had a Kawasaki ZR7. One of the things that alot of people did to stiffen the front was to add a pvc spacer that was longer than the stock one. I have looked through the forum and I could not find if anyone has done this to the strom as the lone temp fix for the problem.

The other question is this. I look at the top of the forks and I can not tell if the preload is all the way down. The center piece with the slot in it sticks up about 3/8 of an inch.

Thanks
Al
The screw preload on the front forks has rings around it. If you're seeing any rings, then the preload is not maxed out.

Something to realize about "stiffening" the front is that adding a longer PVC spacer, or increasing the pre-load with the adjuster does not make the front any stiffer. It only raises the ride height.

If you want a stiffer front end, you need stiffer springs.

Here's sonic's web site LINK

Do some searching around here. There are plenty of threads about upgrading your fork spings, and how to calculate which spring you need based on your weight. Also many threads about setting proper sag once you've got the springs installed.



There's a bit more to it than just dumping longer spacers in and hoping for the best.
 

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Discussion Starter #3
Good to know. Ill check out some of the other threads. The last thing I need is a taller bike since I am 5'6".
 

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Actually,, if you pull out your old springs, cut about 2 to 3 inches off of them, then make a PVC spacer that is 2 or 3 inches longer than the stock one (depending on how much spring you cut out) you will have stiffer springs. Cut the spring from the tigher coiled end since stock springs are progressive, then heat the last coil with a propane torch and push it flat. A little work with the grinder will finish the job. clean it good, reinstall with some fresh oil, and enjoy stiffer spring without throwing away $100 to someone else.

How it works. by cutting the spring you reduce the number of active coils. the fewer active coils, the more force is spread out amoung the remaining coils, coils only get stiff because of torque, fewer coils, same torque equals stiffer spring.
 

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Actually,, if you pull out your old springs, cut about 2 to 3 inches off of them, then make a PVC spacer that is 2 or 3 inches longer than the stock one (depending on how much spring you cut out) you will have stiffer springs. Cut the spring from the tigher coiled end since stock springs are progressive, then heat the last coil with a propane torch and push it flat. A little work with the grinder will finish the job. clean it good, reinstall with some fresh oil, and enjoy stiffer spring without throwing away $100 to someone else.

How it works. by cutting the spring you reduce the number of active coils. the fewer active coils, the more force is spread out amoung the remaining coils, coils only get stiff because of torque, fewer coils, same torque equals stiffer spring.
I'm not sure that's correct.
The stock springs take 0.7kg to compress one cm, untill the bottom out (ignoring the progressive aspect).
Since the PVC spacer won't compress, the rest of the spring still will take 0.7kg/cm to compress. It will, however, bottom out 2-3 inches sooner. I don't see that as an improvement.

When considering the progressive aspect, it makes a bit more sense. Say the spring is .6 low and .8 high. If you chop off half the spring from the low end, you'll get .8 springs--and half the fork travel. That's a hell of a lot sacrifice for a gain of .1 kg/cm.
With only 2 inches, you're not going to see any noticeable gain.



(Unless I'm wrong)
 

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I'm not sure that's correct.
The stock springs take 0.7kg to compress one cm, untill the bottom out (ignoring the progressive aspect).
Since the PVC spacer won't compress, the rest of the spring still will take 0.7kg/cm to compress. It will, however, bottom out 2-3 inches sooner. I don't see that as an improvement.

When considering the progressive aspect, it makes a bit more sense. Say the spring is .6 low and .8 high. If you chop off half the spring from the low end, you'll get .8 springs--and half the fork travel. That's a hell of a lot sacrifice for a gain of .1 kg/cm.
With only 2 inches, you're not going to see any noticeable gain.



(Unless I'm wrong)

Think of it like this..

You've got a spring that has 10 coils. When you put 100 lbs on the spring each coil compresses 1/10th of an inch compressing the entire spring 1 inch.
So your spring rate is 100lbs/inch

Cut 5 coils off the spring. Now when you put 100lbs on the spring each coil is still compressing 1/10th of an inch, but now the entire spring is only compressed 1/2 an inch. To get the 1 inch of travel you have to add 100lbs more weight, so now the spring rate for your shorter spring is 200lb/inch. The shorter spring is a stiffer spring.

You can only cut a spring down so much before it coil binds at or before full compression. So, be sure to measure all the gaps in the spring and add them up. If you've got more distance in the gaps including however much pre-load you put on the spring to get correct sag, than you have in suspension travel, you are good to go.
 

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I'm not sure that's correct.
The stock springs take 0.7kg to compress one cm, untill the bottom out (ignoring the progressive aspect).
Since the PVC spacer won't compress, the rest of the spring still will take 0.7kg/cm to compress. It will, however, bottom out 2-3 inches sooner. I don't see that as an improvement.

When considering the progressive aspect, it makes a bit more sense. Say the spring is .6 low and .8 high. If you chop off half the spring from the low end, you'll get .8 springs--and half the fork travel. That's a hell of a lot sacrifice for a gain of .1 kg/cm.
With only 2 inches, you're not going to see any noticeable gain.

(Unless I'm wrong)
Cutting the springs do stiffen the ride. I know because I cut mine. But even after cutting they are not stiff enough. I will be installing a set of Sonic 1.0 kg/cm.
 

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What Kinda Bike Is That?
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It only raises the ride height.
The springs are housed in a fixed, length tube. Adjusting pre-load on the front does not adjust the height. But, adjusting the pre-load on the rear does.
 

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What Kinda Bike Is That?
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If you want a stiffer front end, you need stiffer springs.

The viscosity of the fork oil determines the "stiffness" of the compression stroke. The weight rating of the spring determines the "stiffness" of the rebound stroke. The two work in concert to achieve the desired ride, (based on bike weight, "add-ons" weight, your weight with riding gear, description of terrain that you travel on and riding style.)


B.
 

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FORUM GODFATHER.....R.I.P. PAT
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Changing the preload on the front forks absolutely changes the ride height, just like the rear. Both ends sit on top of a partially compressed spring. If either end has no sag and the spring is fully extended, the suspension is set up wrong and a terrible ride will result. While a heavier oil will have an effect on the suspension, the oil weight needs to be matched to the spring rate. Otherwise, too heavy an oil will not allow the forks to fully rebound on a series of washboard bumps and the suspension will pack down. Too light an oil will allow too much rebound and the forks will pogo, maybe even leaving the ground. The way to stiffen a fork or shock is to use a stronger spring and a heavier oil. Some stiffening of the front can be accomplished by adding more oil to reduce the air space so the air is harder to compress. I'm totally in Gramps' corner here.
 

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Changing the preload on the front forks absolutely changes the ride height, just like the rear.
I stand corrected on "pre-load changing ride height" on the forks.

My perspective was, there is minimal change in ride height by changing the fork pre-load as compared to the ride height I can affect by adjusting the pre-load on my rear Hyperpro shock.

Here is a quote from Rich Desmond's site:

"You can also use preload to make small changes to the ride height. Generally it's better to move the fork tubes up or down in the triple clamps to accomplish this, but on some bikes that's not possible. In those cases a little compromising between the perfect sag and the perfect ride height may in order. Sag is important though, so don't go any more than 10mm in either direction."

The link to the whole article is here: http://www.sonicsprings.com/catalog/preload_tech_article.php

Gramps' post stated, "If you want a stiffer front, you need stiffer springs." My response to that was to caution just changing the springs. The oil and springs work in "concert" with each other. Assuming that both are chosen correctly, (meaning matched), based upon the variables that I mentioned.

Thanks for the correction and clarifications, Pat.

Barry
 

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The springs are housed in a fixed, length tube. Adjusting pre-load on the front does not adjust the height. But, adjusting the pre-load on the rear does.

Actually it does. It adjusts sag which is ride height. The less sag there is, the higher in the fork travel the forks will be in their "resting" state, so the higher the bike will ride.

Sure it won't adjust out maximum height, but if you're running the forks topped out at max height, your ride is going to be terrible.

The rear shock is also a set length. Adding pre-load to the rear shock only makes the rear ride higher or lower in the total travel of the shock. It is still limited in height by the actual fully extended length of the shock, which never changes.

Now you can change the links on the rear to affect ride height, but that's not what we've been talking about.


EDIT: Oops, didn't see that your post was the bottom of one page and that there was another page of discussion..
 

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Gramps' post stated, "If you want a stiffer front, you need stiffer springs." My response to that was to caution just changing the springs. The oil and springs work in "concert" with each other. Assuming that both are chosen correctly, (meaning matched), based upon the variables that I mentioned.

You're right, I should have chosen my words better. The way I see it is that springs affect firmness, and oil affects stiffness.

Firmness being how the suspension responds to slow speed changes such as braking, and stiffness being how the suspension responds to higher speed changes like hitting bumps.

Sure it's overly simple, but I think it gets the ball rolling in the right direction when thinking about suspension. Remember that the OP was thinking that adding pre-load makes the front "stiffer", so that's where we were starting from. He was using stiffness in the way that I use firmness, so I was sticking with his words.
 

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Good reading here.

My 2 cents.... If anyone has any intention of taking their Strom off of pavement, it seems completely rediculous to cut and shorten the spring. Cutting the spring and adding a stiff spacer will decrease travel. Maybe for strict street riding or the Strom on the track.....it could be a good fix.

As far as I am concerned, $115 for Sonic Springs and new oil....tuned just right.....is the ticket and a very inexpensive upgrade. Dozens and dozens on this forum have reported phenomenal results.
 

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Good reading here.

My 2 cents.... If anyone has any intention of taking their Strom off of pavement, it seems completely rediculous to cut and shorten the spring. Cutting the spring and adding a stiff spacer will decrease travel. Maybe for strict street riding or the Strom on the track.....it could be a good fix.

Cutting the spring won't necessarily decrease total travel. Only if you cut it so short that it coil binds before full travel is reached. Best way to make sure you won't coil bind is to measure the gaps in the spring and add them up. Then when installed, as long as the measured gaps minus the amount of preload is equal to or more than total travel of the forks, you'll still have total travel.
 

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For those of you posting that are correct I doubt you will ever convince the I Know boys that you are correct. I'm just saying:sifone::var_52::party:
 
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