New fork spring rate recommendations - SV1000 Portal
 4Likes
Reply
 
LinkBack Thread Tools Rate Thread Display Modes
post #1 of 33 (permalink) Old 9th September 2020, 06:58 PM Thread Starter
Forum whore
 
tzk321's Avatar
 
Join Date: May 2003
 ♂ United States
Virginia
Posts: 2,731
New fork spring rate recommendations

My 2003 SV1000N has ~52,000 miles. The fork springs are still within spec but since I'm running out of things to tweak I thought I might change them anyway.

According to Race-Tech the stock spring rate is 0.98 kg/mm
Race-Tech recommends a rate of 0.86 kg/mm and the closest available is 0.90 kg/mm.

I currently have the preload at the max with the stock springs. If I use the springs that they recommend won't I have too much sag?

"Hypocrisy isn't the Republicans' weakness. It's their platform" - Seth Myers
tzk321 is offline  
Sponsored Links
Advertisement
 
post #2 of 33 (permalink) Old 9th September 2020, 07:48 PM
Weekend cruiser
 
Masta' C's Avatar
 
Join Date: Aug 2019
 ♂ United States
Posts: 137
You can pretty much ignore the stock rate they are reporting. Because the stock springs are progressive, the rate they provide is not a good indicator of how the straight rate springs will compare. Basically, the stock springs start at a rate much lower than 0.98 and then increase to somewhere around 0.98 as the spring fully compresses.

You'll actually find it easier to set correct sag with a proper straight-rate spring.

In your case, 0.90 would probably be the way to go.
Masta' C is offline  
post #3 of 33 (permalink) Old 9th September 2020, 10:39 PM
Disturbed, very...
 
Missing Link's Avatar
 
Join Date: Dec 2017
 ♂ Australia
Queensland, Orstraylya
Posts: 1,137
Garage
How hefty are you ?

If you have been honest on the calculator, then .90 will be fine.
They will be stiff at first, but will soften up nicely..

If you haven't done springs before, the new ones will be shorter....
Meaning you will have to make a spacer to make the new setup the same length as an orignal oem spring...
I made a alloy spacer washer to do the job, sat under the plastic spacer tube.....

One owner..... 311,000kms and counting...

2003 Copper SV1000S
Repainted Ford PE (Petroleum Mica)
Yoshi 2:1 collectors and Arrow titanium can...
Missing Link is offline  
 
post #4 of 33 (permalink) Old 10th September 2020, 08:11 PM
KNEE DRAGGER
 
schmidt314's Avatar
 
Join Date: Nov 2005
 ♂ United States
Portland Oregon
Posts: 5,043
Garage
Quote:
Originally Posted by Missing Link View Post
How hefty are you ?



If you have been honest on the calculator, then .90 will be fine.

They will be stiff at first, but will soften up nicely..



If you haven't done springs before, the new ones will be shorter....

Meaning you will have to make a spacer to make the new setup the same length as an orignal oem spring...

I made a alloy spacer washer to do the job, sat under the plastic spacer tube.....


Why will they be stiff at first then soften up?
If the spring is collapsing or changing rate significantly, that to me would be a poorly engineered/manufactured spring.

-ms
Longhair likes this.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
schmidt314 is offline  
post #5 of 33 (permalink) Old 10th September 2020, 10:12 PM
Disturbed, very...
 
Missing Link's Avatar
 
Join Date: Dec 2017
 ♂ Australia
Queensland, Orstraylya
Posts: 1,137
Garage
Quote:
Originally Posted by schmidt314 View Post
Why will they be stiff at first then soften up?
If the spring is collapsing or changing rate significantly, that to me would be a poorly engineered/manufactured spring.

-ms
Just from experience.....after the first few rides they seem to become more compliant.....seat of the pants thing i spose.......wait....maybe thats were i go wrong....i am sitting on the triples ?

One owner..... 311,000kms and counting...

2003 Copper SV1000S
Repainted Ford PE (Petroleum Mica)
Yoshi 2:1 collectors and Arrow titanium can...
Missing Link is offline  
post #6 of 33 (permalink) Old 19th September 2020, 08:02 PM Thread Starter
Forum whore
 
tzk321's Avatar
 
Join Date: May 2003
 ♂ United States
Virginia
Posts: 2,731
Quote:
Originally Posted by Missing Link View Post
If you haven't done springs before, the new ones will be shorter....
Meaning you will have to make a spacer to make the new setup the same length as an
Should the new spring + spacer combination be equal to the stock spring + spacer length?

"Hypocrisy isn't the Republicans' weakness. It's their platform" - Seth Myers
tzk321 is offline  
post #7 of 33 (permalink) Old 20th September 2020, 12:45 AM
KNEE DRAGGER
 
schmidt314's Avatar
 
Join Date: Nov 2005
 ♂ United States
Portland Oregon
Posts: 5,043
Garage
Quote:
Originally Posted by tzk321 View Post
Should the new spring + spacer combination be equal to the stock spring + spacer length?


In some cases yes, and some cases no.
-ms


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
schmidt314 is offline  
post #8 of 33 (permalink) Old 20th September 2020, 01:11 AM Thread Starter
Forum whore
 
tzk321's Avatar
 
Join Date: May 2003
 ♂ United States
Virginia
Posts: 2,731
OK. What about in my case?

"Hypocrisy isn't the Republicans' weakness. It's their platform" - Seth Myers
tzk321 is offline  
post #9 of 33 (permalink) Old 20th September 2020, 06:28 AM
KNEE DRAGGER
 
schmidt314's Avatar
 
Join Date: Nov 2005
 ♂ United States
Portland Oregon
Posts: 5,043
Garage
Quote:
Originally Posted by tzk321 View Post
OK. What about in my case?


My numbers show that with a 0.9kgf/mm spring with the preload adjusters backed all the way out, you need 12mm preload onto the spring when the cap is installed.
-ms


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
schmidt314 is offline  
post #10 of 33 (permalink) Old 20th September 2020, 10:42 PM
Forum whore
 
Join Date: Feb 2011
 ♂ United States
SW Pennsylvania, USA
Posts: 2,148
I have .90 RaceTech springs and the stock spacers needed to be cut about an inch IIRC. Easy way to do it: have front end lifted off of ground with forks fully extended. Place spacers and caps with preload adjusters fully wound out and see how far you must compress the stack to get them to thread in. Stock spacers were WAY out needing a really hard effort to compress and get threads started...which is no good. Cut spacer until maybe 1/4" needs to be compressed to get the threads started and this will be about right. If you can't get your sag set properly...either cut more of the spacer or add washers to suit. Not hard and no real measuring needed....if you can compress the spring a bit to get the cap on it's going to be really close.
RecoilRob is offline  
post #11 of 33 (permalink) Old 20th September 2020, 10:48 PM
Disturbed, very...
 
Missing Link's Avatar
 
Join Date: Dec 2017
 ♂ Australia
Queensland, Orstraylya
Posts: 1,137
Garage
Quote:
Originally Posted by schmidt314 View Post
My numbers show that with a 0.9kgf/mm spring with the preload adjusters backed all the way out, you need 12mm preload onto the spring when the cap is installed.
-ms
I have 1.0kg springs in mine..... (gixxer front end) what should i be using spacer wise ? I just matched the spring/spacer combo.....had to cut the spacer down to
get that figure...

One owner..... 311,000kms and counting...

2003 Copper SV1000S
Repainted Ford PE (Petroleum Mica)
Yoshi 2:1 collectors and Arrow titanium can...
Missing Link is offline  
post #12 of 33 (permalink) Old 20th September 2020, 11:13 PM
KNEE DRAGGER
 
schmidt314's Avatar
 
Join Date: Nov 2005
 ♂ United States
Portland Oregon
Posts: 5,043
Garage
Quote:
Originally Posted by Missing Link View Post
I have 1.0kg springs in mine..... (gixxer front end) what should i be using spacer wise ? I just matched the spring/spacer combo.....had to cut the spacer down to

get that figure...


It depends on what front end. In most cases though on those forks if you buy the exact right spring, you use the stock spacers.
-ms


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
schmidt314 is offline  
post #13 of 33 (permalink) Old 21st September 2020, 07:04 AM
Disturbed, very...
 
Missing Link's Avatar
 
Join Date: Dec 2017
 ♂ Australia
Queensland, Orstraylya
Posts: 1,137
Garage
Yeah...i had a look on Racetech, they have 10mm as the preload.....

So, i measure the free length of the spring....270mm from memory, then with the preload adjuter right out, the spring should be compressed 10mm ?
If more, then the spcer is too long, or less, i need more spacer.... me thinks thats right, ya ?

One owner..... 311,000kms and counting...

2003 Copper SV1000S
Repainted Ford PE (Petroleum Mica)
Yoshi 2:1 collectors and Arrow titanium can...
Missing Link is offline  
post #14 of 33 (permalink) Old 21st September 2020, 11:09 PM
Disturbed, very...
 
Missing Link's Avatar
 
Join Date: Dec 2017
 ♂ Australia
Queensland, Orstraylya
Posts: 1,137
Garage
....revisited the Racetech page....says 2 things.... see attached

Recommended Preload - Actual 10mm

Recommended Preload - Relaxed 30mm (click for details doesn't work)

Now, me wonders what it means, as they show sag as 35mm elsewhere....

I would email them, but, previous experience has taught me that the one word answers they give
dont inspire confidence or assurance.....

So, can someone shed some light please ?
Attached Images
File Type: jpg preload.JPG (46.6 KB, 6 views)

One owner..... 311,000kms and counting...

2003 Copper SV1000S
Repainted Ford PE (Petroleum Mica)
Yoshi 2:1 collectors and Arrow titanium can...
Missing Link is offline  
post #15 of 33 (permalink) Old 22nd September 2020, 01:44 AM Thread Starter
Forum whore
 
tzk321's Avatar
 
Join Date: May 2003
 ♂ United States
Virginia
Posts: 2,731
What do they mean by actual and relaxed preload???
Missing Link likes this.

"Hypocrisy isn't the Republicans' weakness. It's their platform" - Seth Myers
tzk321 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the SV1000 Portal forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes Rate This Thread
Linear Mode Linear Mode
Rate This Thread:



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome