Help With Spring Choice?

Pelikan · January 31, 2011, 04:37:07 AM

Well, I've read a ton of threads and am still unsure what to do. I know that I don't much care for the stock springs. For most riding I don't notice too much trouble, but when I brake and/or downshift, the front end dips (annoying). I'm trying to clear this up without having an uber-stiff hard ride. I do some spirited runs from time to time, but I'm no street racer.

Given this, it seems like I should be leaning toward the progressives. Will they help with nose dive?

If I go with uprated springs, should I also get a Katana rear to keep things balanced?

Which oil weight?

Shepa · January 31, 2011, 05:51:27 AM

Why don't you try using a longer fork spacers and 15W fork oil for start ?
Much cheaper solution.

At first, I've tried a 45 mm longer spacers, but front was way too stiff and quite wobbly on higher speeds.
So I reduced them to 35 mm (longer than original), and in combination with 15W oil, I'm satisfied.
No more bottoming, no more floating around the road, and unexpected situations in corners.

I've instaled a SV650 rear shock, and with full spring preload (for open road only), the rear is firm and stable in all kind of corners, at any kind of speeds.

Pelikan · January 31, 2011, 06:14:52 AM

I don't want to chance stripping the cap threads, so I'm paying a guy to do it (I.e., $50 or so for the springs isn't much of a concern). Just want to get it right the first time. I hear people say linear is the way to go, I hear people say progressive is the practical option.

The only problem I'm really trying to fix is that nose dive, while still having a reasonably comfortable/livable/daily-driver ride quality.

Shepa · January 31, 2011, 06:48:33 AM

Well... when you live where I do, you have to improvise.

If you can have a right type of springs, with correct spring-rate for your weight, for a reasonable amount of $, and all that without having to wait for eternity to have it installed on your bike... what can I say...

Anyway, track racers I know swear that linear springs give a better feedback and are more predictable, so if I were you, I wouldn't opt for progressive ones. But that's just me.

centuryghost · January 31, 2011, 10:01:10 AM

My opinion, straight rate.

I have .90 sonic springs installed and it is by far the best thing I have ever done for my GS. I chose linear because I like a tighter suspension feel, plus I don't believe the GS has enough spring travel to make the progressives work properly, i.e they will still feel a bit soft.

Definitely upgrade the rear spring as well. I have the yellow SV on mine and while I like the height it offers, it still feels a bit soft but better than the stocker.

Money well spent

Pelikan · January 31, 2011, 02:44:22 PM

Mmm-kay...0.90 sonics ordered plus a really good condish Katana 600 rear. Fingers crossed.

GAS · January 31, 2011, 03:13:18 PM

Quote from: Pelikan on January 31, 2011, 02:44:22 PM
Mmm-kay...0.90 sonics ordered plus a really good condish Katana 600 rear. Fingers crossed.

I've made almost the same (used katana750 rear) and it was a really good combination.

I weight 180 pounds geared, the sonics website has a calculator tool for you bike and your weight, make sure .90 is indicated for you!

Pelikan · January 31, 2011, 03:19:13 PM

Couldn't find the sonic calculator, but the one on Racetech's website said about 0.88-0.89 is ideal for me (rounded up to 0.90). Am getting 15w oil to put in, if that makes a difference. Just trying to be done with this sloppy front fork.

Any idea what to set the preload for on the Katana? I'm about 190 geared.

Suzuki Stevo · January 31, 2011, 10:02:46 PM

Quote from: Pelikan on January 31, 2011, 03:19:13 PM
Couldn't find the sonic calculator, but the one on Racetech's website said about 0.88-0.89 is ideal for me (rounded up to 0.90). Am getting 15w oil to put in, if that makes a difference. Just trying to be done with this sloppy front fork.

Any idea what to set the preload for on the Katana? I'm about 190 geared.

http://www.sonicsprings.com/catalog/calculate_spring_rate.php?osCsid=e06e80eb983d8c77ba72b6037e50a561

Pelikan · February 01, 2011, 02:06:56 PM

In light of the above calculator and after speaking to Rich about my riding habits and needs, he suggested I bump down to 0.85 plus 15w oil. Imma go with that.

gearman · February 01, 2011, 04:36:39 PM

Quote from: Pelikan on February 01, 2011, 02:06:56 PM
In light of the above calculator and after speaking to Rich about my riding habits and needs, he suggested I bump down to 0.85 plus 15w oil. Imma go with that.

That's the setup we installed on my sons GS and it was a huge improvement. Still need to deal with the rear.

tundrav8 · February 01, 2011, 06:17:55 PM

I just ordered the .85 sonic springs for my GS- Is there an easy way to install them without pulling out the forks??

centuryghost · February 01, 2011, 06:20:46 PM

Quote from: tundrav8 on February 01, 2011, 06:17:55 PM
I just ordered the .85 sonic springs for my GS- Is there an easy way to install them without pulling out the forks??

There's the "lazy man's" way which is leave the forks on and pull the old springs out of the top and replace with new. But then you don't get to change your fork oil. I don't see a point in changing fork springs and leaving nasty old oil in there.

tundrav8 · February 01, 2011, 06:23:06 PM

my bike only has 2,000 miles- should i change the fluid?
Is there a good website to get the rear katana shock from? and what year katana shock will be a direct replacment?

centuryghost · February 01, 2011, 06:25:24 PM

Quote from: tundrav8 on February 01, 2011, 06:23:06 PM
my bike only has 2,000 miles- should i change the fluid?
Is there a good website to get the rear katana shock from? and what year katana shock will be a direct replacment?

Sonic Springs will recommend that use up the weight of your oil to 15w.

Katana shock = Ebay

SAFE-T · February 01, 2011, 09:47:11 PM

I always thought the RaceTech/Sonic spring rates were a bit too stiff for regular street riding. I think you will find the .85's will firm up the forks just the right amount. I know others who have put 'suggested' spring rates of .90 - 1.0 on their bikes and wound up going back to .85.

Straight rate springs are typically favored by suspension tuners for race bikes since the riding surface is more consistent and it allows them to tune the suspension using other components found in more advanced forks. On the GS500 I don't think I would get too wound up

about straight rate vs. progressive rate springs.

Shepa · February 02, 2011, 06:40:59 AM

Quote from: centuryghost on February 01, 2011, 06:20:46 PM
Quote from: tundrav8 on February 01, 2011, 06:17:55 PM
I just ordered the .85 sonic springs for my GS- Is there an easy way to install them without pulling out the forks??

There's the "lazy man's" way which is leave the forks on and pull the old springs out of the top and replace with new. But then you don't get to change your fork oil. I don't see a point in changing fork springs and leaving nasty old oil in there.

How about a large syringe with a piece of rubber hose (half a meter's more than enough) on it?

centuryghost · February 02, 2011, 09:31:05 AM

Quote from: Shepa on February 02, 2011, 06:40:59 AM
Quote from: centuryghost on February 01, 2011, 06:20:46 PM
Quote from: tundrav8 on February 01, 2011, 06:17:55 PM
I just ordered the .85 sonic springs for my GS- Is there an easy way to install them without pulling out the forks??

There's the "lazy man's" way which is leave the forks on and pull the old springs out of the top and replace with new. But then you don't get to change your fork oil. I don't see a point in changing fork springs and leaving nasty old oil in there.
How about a large syringe with a piece of rubber hose (half a meter's more than enough) on it?

That works. But you still will have old oil down in there, the syringe can't get it all. If you are going to go through the process of putting awesome new springs in there, why cut corners?

RichDesmond · February 02, 2011, 10:54:04 AM

Quote from: tundrav8 on February 01, 2011, 06:23:06 PM
my bike only has 2,000 miles- should i change the fluid?
Is there a good website to get the rear katana shock from? and what year katana shock will be a direct replacment?

It's the first few thousand miles that really gunk up the oil. Lots of wear metals from the bushings and sliding surfaces wearing into each other. After that first change I generally do the fork oil when I change a front tire, since getting the wheel off is half the work anyway.

RichDesmond · February 02, 2011, 11:02:43 AM

Quote from: SAFE-T on February 01, 2011, 09:47:11 PM
I always thought the RaceTech/Sonic spring rates were a bit too stiff for regular street riding. I think you will find the .85's will firm up the forks just the right amount. I know others who have put 'suggested' spring rates of .90 - 1.0 on their bikes and wound up going back to .85.

Straight rate springs are typically favored by suspension tuners for race bikes since the riding surface is more consistent and it allows them to tune the suspension using other components found in more advanced forks. On the GS500 I don't think I would get too wound up about straight rate vs. progressive rate springs.

We try with our calculator to let the customer tailor the options so that it matches their needs. Very important with the GS to pick the Standard/Sport Touring option instead of Sport Bike even if you have the F model. That said, if you have doubts at all about your rate please shoot us an email and ask, we're more than happy to make sure you get the right rate.

On the straight rate/progressive issue, we do firmly believe that straight rate springs are better, even on the street with widely varying conditions. For the average street rider though the difference isn't that huge, so you're right, no need to get "wound up" about it.

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Help With Spring Choice?