Author Topic: Sonic 1.2 Springs- Preload ?  (Read 913 times)

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Offline Brian_Depew_LA

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Sonic 1.2 Springs- Preload ?
« on: May 06, 2012, 05:53:13 pm »
I installed the Sonic 1.2 springs and changed the fork oil to Bel ray 15 W. I set the preload at #5. It fells kind of stiff. I didn't get to test ride yet just wondering what you guys use for preload with the sonic springs? I am 240 Lbs, aggresive rider and try to keep the bike light most of the times no saddlebags and just rain gear in the tail trunk. I might start at # 3 preload setting kind of the middle setting when I get a chance to test it out.

Offline Daytona_Mike

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Re: Sonic 1.2 Springs- Preload ?
« Reply #1 on: May 06, 2012, 11:02:01 pm »
Pre load has absolutely nothing  to do with softer or stiffer. All the way in and all the way out on the pre load will give  the exact same spring rate or as you would say 'stiffness'.
Pre loads' purpose is to set up the geometry  or ride height of the bike which is the sag setting. Screw it in and the bike goes up and nothing more then that.
 The only way to  change stiffness (rate) is to change springs.
Now rebound and damping is a different story. Your dampening may be too harsh. This is where emulators , fork fluid  viscosity and fluid level would help you.
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Offline Eddie-SC

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Re: Sonic 1.2 Springs- Preload ?
« Reply #2 on: May 07, 2012, 12:16:28 am »
Here's a link to a good article about setting static sag using preload.

Good luck!
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Offline mdr

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Re: Sonic 1.2 Springs- Preload ?
« Reply #3 on: May 10, 2012, 12:46:11 pm »
Not to pick a nit, but the primary effect of pre-load is to set the resting point of the suspension when it's got the rider on board, aka sag.  The ideal result is you use most of all of the suspension travel under 'normal extreme' conditions, that is not bottoming or topping out. 

Damping also plays a role in controlling the travel, but again, that's not it's primary job - unless it's being used to try to compensate (poorly btw) for too 'light' a spring.

Preload secondarily affects trail, which affects handling.  That can more directly be adjusted by raising the forks in the triple clamps to lower the front of the bike while maintaining the proper sag.  Lowering the front adds a bit more weight to the front so it can also affect the sag height, but it's a secondary effect.

Sport Rider has lots of articles about suspensions in addition to the sag article.  Your homework is to go poke around over there and learn up.  It sounds complicated, but when you break it down and change one thing at a time, you'll get a better feel for what does what and how to fiddle with it!
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