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Beta450

Race Tech Spring Rate Calculator

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This is for the suspension tuners.  

How accurate is the Race Tech Spring Rate Calculator in determining your spring rate and should one round up or down when in between rates?

 

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From my experiences with them, the calculator seems really accurate for popular "mainstream" brands and models, but less so for smaller, lesser known brands.  Probably a reflection of just how much they have researched and developed products for each.

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28 minutes ago, Beta450 said:

This is for the suspension tuners.  

How accurate is the Race Tech Spring Rate Calculator in determining your spring rate and should one round up or down when in between rates?

 

For fork spring rates seem pretty on par, but bad quality springs to be had from them.

For progressive shocks springs i would not trust or use theirs, the rates advertised are not what you get atleast on the 3 springs over years ive had from them

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Generally pretty close but there are so many variables that we very often do not use the same rates. Most of R.T.s springs are Eibach. Good springs. The Variable we do not use Eibach or WP simply due to the rate curve. Tuning a variable rate spring is not as easy to hit the sweet spot as a straight rate. It may take some homework to make a variable work. Before we hit the sweet spot with Noah Kepple last endurocross season we tested I believe 5 variable springs with two of them custom rate curves along with a couple straight rates.  We found a variable that "really" worked with the valving tuned accordingly. Among the variable springs there was an Eibach and a WP in the mix.

Spring rate example is the Baja team. 185lb rider 40yr old pro class, CRF450X we ran .50kg forks springs. Single track 185lb rider 450X we may well run .46 A lighter spring will also have better cornering performance as it will sink a bit lower in the turn so you can rail like Nantista and his compatriots or even like Bikeslut on his old compliant DRZ. Surprisingly fast in the corners but have you ever seen him rip a whoop section?

Some people like to ride the spring. KTM open bath forks are an example of riding the spring meaning less valving and more spring. This is more lively for rocky sections, single track etc. Not such an advantage at high speed but great for tight rocky stuff.

I would rather error on the stiff side as there are more advantages and safety. Too soft can be harsh and dangerous in whoops, hidden rock, or crossing a road with the high speed hit. Generally the plushness will not suffer as long as you are in the ballpark.

One last thing. Most times for most people if you are in the ballpark, regarding spring rates especially if it is a substantial change from your previous springs most are enamored with the improvement.

 

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And. When our shock dyno is installed and running we will be testing many springs on the dyno. This will give us quality info and give info to match spring to damping.

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Good Info Giorgio Thanks,

"I would rather error on the stiff side as there are more advantages and safety"

and from experience heavier springs surprisingly can feel more plush than too light springs which don't keep the suspension up and allow the valve to do its job starting from "fully"(more static position) extended.

Unauthorized use of my name without prior consultation?.........PS thanks for the props Mr.  

  FYI for the discussion

 my Husky TE300 has .46s up front and a 5.8 in the back, (I'm at .....210lb at least that's what I keep saying....), note out back the WP TRAX shock does react differently than a standard shock

on my former race spec set up Red Husky TE310 and TXC310R midi Italian 4 strokes I used .48s with 6.0 on the back, 4 strokes dove more with off throttle compression braking, and for chassis balance I used the 6.0 to keep the normal ride height level with the .48s up front, on those I used right at 100mm race sag.

My 3 red Husky 450s used .48s and 6.2 out back for a while I used .50 but went back to .48

My stuff is setup to work in "Tecate"* Single Track

so with these spring numbers you can see that they are all very close even between machine models

* tight rocky single track with scattering of open faster stuff in between.

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FYI- additional,  I found a happy medium place for my fork projection so I can leave it there and make sag adjustments for different riding  ex. I keep close to 100mm race sag for "Tecate" type stuff and for NHHA I drop the rear to near 105mm to get that more safe chopper, higher speed slower steering more stable chassis feel. (and this has saved me big time!!)

My easy no banging/drift punch advantage with this is that I have the Xtrig 8mm screw spring adjuster on my shock with a nice permanent marker line on the adjuster ring, so I break out the speed handle and crank a turn or 2 of the ring to make quick changes to race sag from 100-105 mm race sag is actually right at 2 turns of the spring comp ring.

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Thank you for all of the advise.  The bike that I'm looking at replacing the springs on is a 2007 KTM 525 exc.  I would like to take out some of the harshness on square edges with springs for my weight before doing a revalve.  So what spring brand is recommended?

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32 minutes ago, Beta450 said:

Thank you for all of the advise.  The bike that I'm looking at replacing the springs on is a 2007 KTM 525 exc.  I would like to take out some of the harshness on square edges with springs for my weight before doing a revalve.  So what spring brand is recommended?

Just take it to George at suspension101 and have him figure it out all for you probably has stuff in stock for that bike too. Tell him sdar member

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I used George in the past and nothing but good things to say about him and his work but with a move to Texas and back was in 4 months I have been placed on restriction by the Warden.  

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   Good Morning Gentlemen,

   Mr. Suspension 101 ( George ),  Do you use a rule of thumb for rider weight differences.  Or, as I suspect, is it a more  complex formula?  For example, a rider of 185lbs has setting A vs rider B of 195lbs.  Just raise spring rates one step for every 10lbs as a simple rule of thumb.  I know the answer :unsure:,  straight rate, variable, valving plus rider character. When you did my set-up, I believe you used stiffer spring front and rear because of the everyday water and tools carried, plus my chatter about camping gear. Rider characteristics.  

Suspect it would be dangerous ( literally ) to use my buddies settings simply because he/she has the same moto.

  Thanks for the discussion. Bagstr

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1 hour ago, Bagstr said:

   Good Morning Gentlemen,

   Mr. Suspension 101 ( George ),  Do you use a rule of thumb for rider weight differences.  Or, as I suspect, is it a more  complex formula?  For example, a rider of 185lbs has setting A vs rider B of 195lbs.  Just raise spring rates one step for every 10lbs as a simple rule of thumb.  I know the answer :unsure:,  straight rate, variable, valving plus rider character. When you did my set-up, I believe you used stiffer spring front and rear because of the everyday water and tools carried, plus my chatter about camping gear. Rider characteristics.  

Suspect it would be dangerous ( literally ) to use my buddies settings simply because he/she has the same moto.

  Thanks for the discussion. Bagstr

Of course there are variables.  The springrate calculator on the Racetech website asks what level of expertise you think you are (sort of subjective, I guess), what type of riding you will be doing: trail riding, enduro/desert, motocross or supercross, also asks how tall you are and whether or not you are over 45 years old.  At least it asked these questions the last time I used it to look for spring rates on a specific model.

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