Fork spring advice please

roadriderg said:
Check rider sag front and rear, are they correct? Maybe too much pre-load?
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+1. I weigh 210 lbs. When I put .95 Race Tech springs in my ST I had to set my preload/sag to my weight by adding spacers. I would bet that at 165 lbs you'll need to remove some spacers. According to everything I've read, you want 36 mm sag for the ST.

Check you sag to see if you need to remove some spacers. If not just the oil change should work.
 
Reginald said:
+1. I weigh 210 lbs. When I put .95 Race Tech springs in my ST I had to set my preload/sag to my weight by adding spacers. I would bet that at 165 lbs you'll need to remove some spacers. According to everything I've read, you want 36 mm sag for the ST.

Check you sag to see if you need to remove some spacers. If not just the oil change should work.
Click to expand...

See my updated post concerning the target rider sag.
 
Update:
I rebuilt the forks using new bushings, seals, etc...and verified the springs are racetech .90 springs.
Used ss7 fluid to recommended racetech level.
I have not been out on a test ride yet.
I am curious if anyone has a simple procedure for checking the sag level that I can check on my own without another persons help.?
 
Put the bike on the center stand to unload the front end (forks and tire in air). Put a zip tie snugly around the fork tube, just above your seal wipers. Measure from this zip tie to the lower triple tree clamp.

Take the bike off the stand, and let the bike settle into the suspension. Very carefully, put it back on the center stand. Remeasure from the zip tie to the lower triple tree clamp.

This will give you a pretty close indicator of sag.

Sent from my SPH-L710 using Tapatalk
 
That's where I have mine set. Was told by both Racetech and Sonic that that is the sweet spot for the 1300.
 
If you leave the cable tie in place,go for a ride and you can then see how much the forks dive under braking/normal conditions.
 
I like 36mm but the bike will be slower steering and may run wide in corners because of the frame/steering geometry changes wrought by decreasing sag 10 mm or more with the new fork springs. Mine originally had 47 mm of rider sag. 11mm of front ride height change is huge. Depending on the presence and type of risers you may have you can slide the forks up in the clamps about 5 or 6 mm to regain some of the steering geometry change the new springs caused. Lots of guides suggest 30 mm of rider sag in the back but I run about 25 to regain most of the steering geometry lost with the fork spring changes.
 
Last edited:
Well, after a120mile ride I am quite pleased with the results of the work I've done. No more rocking front to rear and a much smoother ride.
Still performs great in the twisties.
Here'a summary of what I did:

Rebuilt front forks with new bushings, seals, and ss-7 fluid.
Verified they indeed have .90 racetech springs and filled to correct level.
Set preload to 36mm.
Refilled rear shock adjuster and set preload and rebound.

Thank you everyone for your assistance!
 
tonyp12 said:
Well, after a120mile ride I am quite pleased with the results of the work I've done. No more rocking front to rear and a much smoother ride.
Still performs great in the twisties.
Here'a summary of what I did:

Rebuilt front forks with new bushings, seals, and ss-7 fluid.
Verified they indeed have .90 racetech springs and filled to correct level.
Set preload to 36mm.
Refilled rear shock adjuster and set preload and rebound.

Thank you everyone for your assistance!
Click to expand...

Just to clarify did you set your front fork preload with 36 mm or is that your rider sag number?
 
Yes, that's rider sag. Some refer to it as static sag. Free sag is measured the same method but without a rider on the bike. The difference between rider and free sag gives an indication how much preload is required to support the weight of the rider ..... Which in turn indicates if the spring rate of the springs is good for his/ her weight.
 
tonyp12 said:
Just curious about something: Does more rider sag equal a softer ride?
Click to expand...
Yes, less preload equals more sag which gives you a softer ride but compromises your suspension travel. Meaning that you will be more prone to bottoming out. You will also have more fork dive when getting on the front brake.
 
It's a common misconception that adding preload (to reduce sag) results in a firmer ride. Adding preload changes ride height (reduces sag) but cannot change the spring rate of the spring so the ride quality of "softness" or "stiffness" remains the same. The kicker to that is that the ST1300 comes with progressive rate springs. The coils on one end are wound tighter and are easier to compress. Adding preload to a progressive rate spring takes up some of the progression and moves the beginning point of the spring rate further up the curve where it is slightly stiffer. So, adding preload to stock springs can increase stiffness to a small degree but if aftermarket straight rate springs are installed then all preload does is increase ride height and reduces sag.
 
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