Technical Discussion Topics related to Technical Issues

front fork spring rates.

Old 01-02-2013, 09:37 PM
Junior Member
Thread Starter
Join Date: Aug 2012
Posts: 21
jcvtr is on a distinguished road
front fork spring rates.

Hi guys. I am planning (and ordered a 6mm spacer for the rear shock.)
The question is what spring rate do i order for the front fork?
my weight is 220 pound without gear. the bike is used regularly for riding to work. with the occasional (intend ) for trackdays. what weight shd i go for?
I am inclined to 0.9kg/mm. what do u guys think?
jcvtr is offline  
Old 01-02-2013, 10:35 PM
Join Date: Aug 2007
Location: Lake View Terrace, CA
Posts: 5,942
8541Hawk will become famous soon enough
There is no cut and dry answer. It depends on your riding style and what "feels" right to you.

For most riders in your weight range 0.9 -0.95kg\mm seems to work fine.

Though to give an example, when I was running the stock forks I ran 1.05kg\mm springs because I tend to brake late and that is what worked best for me.

One thing I will say is you will need to have the valves set for whatever spring you install.
8541Hawk is offline  
Old 01-03-2013, 02:29 AM
Junior Member
Thread Starter
Join Date: Aug 2012
Posts: 21
jcvtr is on a distinguished road
Thanks man. I figure i have to do both or us leave it stock.
jcvtr is offline  
Old 01-03-2013, 03:40 AM
Senior Member
mikstr's Avatar
Join Date: Apr 2005
Location: Montreal
Posts: 5,561
mikstr is on a distinguished road
I agree with Mike. YOu can check both the Race Tech and Sonic springs web sites as they have rate calculators to help with this type of thing. Curiously, RT recommends slightly stiffer springs than Sonic does.....
mikstr is offline  
Old 01-03-2013, 06:31 AM
Senior Member
JamieDaugherty's Avatar
Join Date: Aug 2005
Location: Fort Wayne, IN
Posts: 1,836
JamieDaugherty is an unknown quantity at this point
Pretty straighforward:

115-150lb > 0.80kg/mm
150-180lb > 0.85kg/mm
180-215lb > 0.90kg/mm
215-250lb > 0.95kg/mm
250-280lb > 1.00kg/mm

This applies to everyone for street and track. The only exception would be an expert track rider on race tires. I've only ever found it necessary to deviate from these rates for VERY special circumstances, so almost never.

Now, if you are on the edge, say 180lb, then you need to make a decision. For most street riders I will go softer unless they are fairly aggressive. Being on step off of ideal is probably not the end of the world but it's best to try and "get it right" if you can. For you = 0.95kg/mm.

I've found +6mm at the rear shock to be a bit much. I think for an otherwise stock bike it makes the handling "feel" better, but +3mm is what I suggest. If you go +6mm now that would be ok, but with other changes (springs/valving in shock and valving in the forks) you will want to drop down for best results.

I hope this helps!
JamieDaugherty is offline  
Related Topics
Thread Starter
Last Post
01-08-2010 09:20 AM
Technical Discussion
05-31-2008 09:22 PM
Technical Discussion
03-25-2008 10:43 AM
Technical Discussion
07-18-2007 06:00 PM
Technical Discussion
04-12-2007 02:18 PM

Thread Tools
Search this Thread
Quick Reply: front fork spring rates.

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.